HK1029544B - Multipurpose folding hand tool - Google Patents

Description

Folding hand tool

Disclosure of Invention

The present invention relates to a multi-function hand tool and more particularly to such a tool having eccentric locking pliers that can be folded into a compact configuration.

Background

Folding multi-function hand tools have become well known in recent years. Representative of several of this type of tool are disclosed, for example, in U.S. Pat. No.4,238,862 to Leatherman, U.S. Pat. No.4,888,869 to Leatherman, U.S. Pat. No.5,212,844 to Sessions et al, U.S. Pat. No.5,267,366 to Frazer, U.S. Pat. No.5,697,114 to MacIntosh, U.S. Pat. No.5,791,002 to Gardiner et al, and U.S. Pat. No.5,809,599 to Frazer. While many such tools have folding pliers, only the pliers disclosed in Thai, U.S. Pat. No.5,029,355, are capable of being locked by an over-center locking mechanism and the jaws are capable of folding to make the tool more compact. Kershaw Multi-ToolTM is currently marketed with eccentric locking pliers, but the jaws cannot be folded. Of course, the best known locking pliers is Peterson Vise-Grip , but it neither folds into a compact stowable shape, nor is it multi-functional.

Previously known multi-function tools with eccentric locking pliers have been of a viable construction but lack strength or practicality, or are unattractive in appearance, or cannot be folded into a suitably compact shape; these tools have not fully achieved their intended purpose.

In multi-function folding tools, various locking mechanisms have been used, such as those proposed in U.S. patent Nos. 5,765,247 to Seber et al and 7,781,950 to Swinden et al, to hold the folding tool head and blade in a desired position, i.e., folded and stowed in a cavity provided in the handle, or rigidly and safely unfolded for use. However, existing latching mechanisms have various disadvantages, both from the standpoint of operability, strength, and reliability, and from the standpoint of manufacturing costs.

Socket wrenches and hexagonal-head screwdrivers are well known. Connectors for connecting hex heads or sockets or both to multi-function tools are also well known. Please see, for example, U.S. Pat. No.4,519,278 to Heldet, U.S. Pat. No.5,033,140 to Chen, U.S. Pat. No.5,251,353 to Lin, U.S. Pat. No.5,280,659 to Park, and U.S. Pat. No.5,809,600 to Cachot. However, the tool bit drive connectors are additional components that must be carried and stored with the multi-function tool to ensure that they can be used to drive the tool bits. Furthermore, the recently available screwdrivers are not well suited for use with special tool bits, such as corkscrews, which require pulling rather than pushing when in use.

Disclosure of Invention

Accordingly, it is desirable to have an improved folding multi-purpose tool comprising pliers with eccentric locking jaws capable of applying high gripping forces, and wherein the jaws are foldable. It would also be desirable to have a folding multi-function tool that includes an improved mechanism for locking and releasing various blades, and a folding multi-function tool that includes an improved holder for holding a hex head tool. Preferably, such tools have a spaced, reliable structure, can be manufactured at reasonable cost, have an attractive appearance, and can be folded into a compact stowed configuration for easy portability and convenient readiness when needed for use. It is also preferred that most of the movement and positioning of the various components of the tool is automated or intuitive to the user when it is desired to use the tool.

The present invention overcomes some of the above-identified problems of the prior art and meets some of the above-identified needs by providing a folding multi-function tool having adjustable locking pliers jaws that can be expanded to an operative configuration in which the tool can be adjusted to grip objects of different sizes and locked by an eccentric mechanism while providing a gripping force on one or more objects positioned between the jaws.

In a preferred embodiment of the tool, a pair of jaws are mounted on a jaw pivot at one end of a first handle, and a corresponding end of a second handle is removably attachable to a lower jaw to control movement of the jaws toward an upper jaw.

In a preferred embodiment of the invention, a jaw shifting device comprises a pair of legs extending between the handles, and the jaws are positioned between the legs when the tool is folded into the compact folded position.

As another separate feature of the invention, a folding tool includes locking pliers with a jaw moving device comprising a pushing body that connects a portion of the jaw moving device to a jaw of the pliers through a swivel joint, the joint comprising cooperating concave and convex surfaces that contact each other, through which the jaw moving device pushes a root of the jaw.

In one embodiment according to this feature of the invention, a snap-lock latch arrangement is provided to enable the swivel joint to be assembled as required and easily disassembled to allow the jaws to be folded into the handle, thereby allowing the tool to assume its compact folded configuration.

It is a separate feature of the present invention to provide a latch mechanism to hold one or more folding blades or tool heads in a selected position relative to a handle of the multi-function folding tool.

In one embodiment according to this feature of the invention, the mechanism includes a latch release lever mounted on a pivot located in a slotted portion of a handle and a spring forming a portion of the handle to retain a catch on the latch release lever in engagement with at least one blade.

In one embodiment according to this feature of the invention, each blade includes a base defining a notch therein from which the catch body is releasable to allow the blade to move between the folded and unfolded positions while the catch body still prevents the blade from moving beyond its predetermined unfolded position, the handle and the latch release lever cooperating to prevent the catch body from moving beyond its predetermined blade release position.

It is a further separate feature of the present invention to provide a tool bit drive sleeve with a threaded bore at an inner end thereof to enable the tool bit drive sleeve to receive not only a tool bit therethrough, but also a special tool bit having threads at one end thereof.

The above and other objects, features and advantages of the present invention will be more readily understood upon reading the following detailed description of the invention and upon reference to the accompanying drawings.

Description of the drawings

Fig. 1 is a perspective view of a folding multi-function tool of a preferred embodiment of the present invention with the jaws of the locking pliers in the deployed and operative position.

Fig. 2 is a right side view of the folding tool of fig. 1 in a fully folded configuration.

Fig. 3 is a top view of the tool of fig. 1 and 2 in the fully collapsed configuration of fig. 2.

Fig. 4 is a left side view of the folding tool in the fully folded configuration shown in fig. 2.

Fig. 5 is a bottom view of the folding tool in a fully folded configuration.

Fig. 6 is a right side view of the folding tool of fig. 1, with the locking pliers jaws moved to separate the two handles from each other in the first step required to convert the tool from the fully folded configuration to the unfolded and operative configuration.

Figure 7 shows the next step required to convert the locking pliers jaws to the operative configuration.

Fig. 8 is a side view of the folding tool showing the next step, the locking jaws of the tool ready for use, and showing a plurality of folding tool blades carried by the second handle of the tool.

Fig. 8A is a side view of the folding tool in an operative configuration with the jaws of the adjustable locking pliers open and ready for use.

Fig. 9 is a side view of the folding tool in an operative configuration with the jaws closed as shown in fig. 1.

Fig. 10 is a cross-sectional view taken along line 10-10 of fig. 9.

Fig. 11 is a top view taken along line 11-11 in fig. 9, showing the bracket assembly and lower handle portion of the tool, but with the upper handle and folding tool blade shown in fig. 8 omitted for clarity.

Figure 11A is an isometric view of the rear side of the bracket assembly from the top right.

Figure 12 is a side view, partially in section, of a portion of a handle on a locking pliers jaw and tool.

Fig. 13 is a cross-sectional view of a portion of the upper handle and tool jaw taken along line 13-13 of fig. 12.

Fig. 14 is a view of a portion of a tool jaw taken in the direction of line 14-14 of fig. 12.

Fig. 15 is a view of a portion of the tool in the same direction as fig. 9, but with a portion of the handle cut away to show the operational relationship between the various tool elements located in the handle.

Figure 15A is an isometric view of a thrust block and detent spring from the upper right front side with the carriage assembly shown in phantom.

FIG. 16 is a detailed view in the same direction as FIG. 15, showing on an enlarged scale a thrust block and a portion of the lower handle and a heel of the lower jaw.

FIG. 17 is a view similar to FIG. 16, but showing the thrust block removably attached to the lower jaw root.

Fig. 18 is a cross-sectional view taken along line 18-18 of fig. 17.

Fig. 19 is a right side cross-sectional view of the tool taken along line 19-19 in fig. 3.

Fig. 20 is a view similar to fig. 19, showing a view of a tool bit aligned with a tool bit drive socket in the upper handle of the tool.

Fig. 21 is a view of the tool taken along line 21-21 of fig. 20 showing the adjustment block of the locking pliers and also showing the bracket assembly attached to the upper handle.

FIG. 22 is an exploded perspective view of a portion of the lower tool handle and blade lock lever.

Fig. 23 is a sectional view in the same direction as fig. 19, showing a portion of the handle with one of the tool blades locked in the deployed position.

FIG. 24 is a view similar to FIG. 23 showing the blade locking lever moved to a blade release position to move the blade to the folded position.

Detailed Description

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Folding type jaw

Referring now to the drawings which form a part of this disclosure, in one preferred embodiment of the present invention, the folding multi-function tool 30 shown in FIG. 1 has an upper handle 32, also referred to as the first body member, and a lower handle 34, also referred to as the lever. A pair of jaws, an upper jaw 36 and a lower jaw 38, are attached to the handles 32 and 34, respectively. In one preferred embodiment of the multi-function tool 30, the handles 32 and 34 have a generally channel shape facing each other and may be made, by way of example, from fine-blanked stainless steel approximately 0.05 inches thick, while the jaws 36 and 38 may be made by investment casting and appropriate trimming.

The tool incorporates an eccentric jaw locking mechanism that can be adjusted using an adjustment knob 40 located at the rear end 45 of the upper handle 36 to lock the jaws 36 and 38 together while grasping objects of various sizes. The various folding tool blades are generally housed within the lower handle 34 and are rotatable about an axis defined by a pivot shaft 42 extending transversely at a rear end 44 of the lower handle 34. The tool blade may be held in either a folded or an unfolded position by a locking mechanism that includes a locking bar 46. The lock bar 46 may be metal die cast and supported by a lock bar pivot pin 48, the pivot pin 48 extending transversely through holes in both sides of the lower handle 34.

After the lower handle 34 is detached from the lower jaw 38, the multi-function folding tool 30 may be folded into a compact folded configuration, as shown in fig. 2, 3, 4, and 5. The upper jaw 36 and the lower jaw 38 are both carried by the upper handle 32 and are rotatable relative to the upper handle about a main jaw axis of rotation 50 from the position shown in FIG. 1 to the position shown in FIG. 2, the axis of rotation 50 being defined by a jaw pivot 52 extending across both sides of the upper handle 32 near a front end 53 of the upper handle 32. The jaw pivot 52 may be a rivet or may be a solid or tubular bolt and nut engaged by mating threads. The large end of the jaw pivot helps prevent lateral play and misalignment of the jaws.

It will be appreciated that different configurations may be employed to enable the lower jaw 38 to rotate relative to the upper jaw 36 about an axis that does not necessarily coincide with the axis of rotation 50, if desired.

When the multi-function tool 30 is in the folded configuration shown in fig. 2-5, a heel 54 of the lower jaw 38 extends outwardly through a hole 56 located on the outside, i.e., rear portion 58, of the upper handle 32. Similarly, a portion of the upper jaw 36 also extends outwardly through a hole 60 located on the outside, rear portion 62 of the lower handle 34.

When the multi-function tool 30 is in the compact folded configuration shown in fig. 2-5, the front end 53 of the upper handle is flush with the front end 64 of the lower handle 34, and the upper and lower handles 32 and 34 are positioned alongside one another with an inner side or edge 66 of the upper handle 32 abutting and facing an inner side or edge 68 of the lower handle 34. An arcuate projection 70 on each side 71 of the channel of the upper handle 32 adjacent the jaw pivot axis 50 fits snugly into a corresponding recess 72 on each side 73 of the channel of the lower handle 34.

The locking pliers jaws 36 and 38 can be unfolded from the folded configuration shown in fig. 2-5 to the operative configuration shown in fig. 1 by the steps shown in fig. 6-9. First, as shown in fig. 6, the lower handle 34 is moved downward and rearward from the upper handle 32. A bracket assembly 74 connects the upper and lower handles 32 and 34, and a pin 76 that snaps into slots 78 on each side of the upper handle 32 connects the bracket assembly 74 to the upper handle 32. The forward end 82 of the bracket assembly 74 is connected to the forward end 64 of the lower handle 34, as will be described in greater detail below.

When the lower handle 34 is in the position shown in FIG. 6, the jaws 36 and 38 can be rotated outwardly about the main jaw axis of rotation 50 to the position shown in FIG. 7. As shown in FIG. 7, the upper jaw 36 in the deployed position rests on the rear portion 58 of the upper handle 32 at the upper handle front end 53. The lower jaw 38 is also rotated counterclockwise from the position shown in FIG. 6, such that the heel 54 of the lower jaw 38 is exposed below the side 71 of the upper handle 32.

The lower handle 34 is then pushed forward such that the forward end 64 thereof releasably engages the heel 54 of the lower jaw 38, thereby allowing the forward end 64 of the lower handle 34 to rotate about the heel 54 of the lower jaw 38. This is most easily accomplished by rotating the knob 40 to the position shown in fig. 8, and by rotating the lower handle 34 (counterclockwise when the tool is shown) until engagement occurs, the nose 64 engages the heel 54. Once the nose 64 engages the heel 54 of the lower jaw 38, the jaws 36 and 38 can be moved toward one another and toward the jaw position shown in FIG. 9 by rotating the lower handle 34 clockwise about the heel 54 as shown in FIG. 8A.

The lower handle 34, i.e., the lever, is limited in its movement toward the upper handle 32, leaving a space between the upper and lower handles 32 and 34 that can be easily manipulated to move the jaws 36 and 38 away from or toward each other as desired. This limitation of movement of the lower handle 34 is accomplished by a pair of limit stops 84 on the lower handle 34. Preferably, the positive stop 84 is in the form of a similar shoulder formed by a cut out on each side of the lower handle 34 and bent slightly inward into the space between the two sides 73 of the lower handle 34, as shown in FIG. 10.

Referring to fig. 11 and 11A, the carriage assembly 74 includes a pair of carriages 86, preferably made of steel plate, separated at the rear end 80 of the carriage assembly 74 by a carriage block 88, the carriage block 88 being cylindrical in a preferred embodiment of the invention. The pin 76 passes centrally through corresponding holes in the bracket block 88 and bracket 86. Preferably, the pin 76 is a tight fit and must be pressed into the hole 90 to hold the bracket 86 securely on both sides of the bracket piece 88.

When the jaws 36 and 38 are in the deployed and operative configuration shown in FIG. 9, one of the stop arms 92 on each bracket 86 will be aligned with the positive stop 84. A shallow V-notch 93 is preferably provided at the end of each arm 92 to prevent further movement of the upper handle 32 toward the lower handle 34 beyond the position shown in fig. 9. As explained below, this relationship of the positive stop 84 to the stop arm 92 is important in that it enables the jaws 36 and 38 to be locked when grasping an object.

Adjacent to the stop arms 92, a U-shaped portion of the bracket 86 may be beveled to a sharp edge, as shown in fig. 6, to form a wire stripper 99. The wire to be stripped is supported by an adjacent portion of the top edge 68 of the lower handle 34.

Both the upper and lower jaws 36 and 38 are rotatably mounted on a jaw pivot shaft 52, as shown in FIG. 12. When the upper jaw 36 is in the deployed position, as shown in FIGS. 12 and 13, it is held by friction between a small raised cam portion 94 and a retaining spring 96, the retaining spring 96 being defined by a pair of short parallel slits 98 on the rear, outer side 58 of the upper handle 32. This structure is also seen in fig. 3. As shown in FIG. 13, jaws 36 and 38 can be provided with cheek plates 100 and 102, which can be material additionally cast onto the jaws and project laterally from the base of jaws 36 and 38, respectively. The cheek plates 100 and 102 are mirror images of each other in shape and extend laterally outward along the main jaw axis of rotation 50 to centrally retain the jaws 36 and 38 between the sides 71 of the upper handle 32.

As shown in FIG. 12, the upper portion of the upper jaw 36 carries a rearwardly facing surface 106 which abuts the forward end 53 of the rear portion 58 of the upper handle 32 to prevent counterclockwise rotation of the upper jaw 36 relative to the upper handle 32 in a supporting relationship. As a result, when the jaws are in the position shown in FIGS. 1 and 12, the upper jaw 36 can remain stationary relative to the upper handle 32 while the lower jaw 38 can freely rotate about the jaw pivot axis 52.

A short torsion spring 108 has radially extending ends each of which engages a notch in a respective one of jaws 36 and 38 and overcomes the frictional forces between lower jaw 38 and the adjacent surface on upper handle 32 and upper jaw 36 and jaw pivot 52 with sufficient force to separate outer ends 112, 114 of jaws 36, 38, respectively, from one another. Thus, unless the jaws 36, 38 are clamped by manipulation of the handles 32, 34, the jaws 36, 38 will tend to separate from each other until limited by the shape of the jaw base 115 shown in FIG. 12.

When jaws 36 and 38 are rotated about jaw pivot 52 to move them from the extended, operative position to the collapsed position shown in FIGS. 2-5, a small inwardly projecting lug 104, preferably formed by pressing against left side 71 of upper handle 32, will bear against cheek 100 of upper jaw 36 with sufficient friction to hold jaws 36 and 38 in the position shown in FIG. 2 against the opening force of spring 108.

As shown in FIG. 12, the gripping surface of the upper jaw 36 is angled slightly downward relative to the upper handle 32 to provide a comfortable angle for holding the tool 30 when an object is gripped between the jaws 36 and 38. Each jaw 36 and 38 includes a spine portion 116 that is slightly narrower than the working surfaces of the jaws 36 and 38, respectively. Preferably, each face outer end 112, 114 is provided with a narrow V-shaped groove 118 (see fig. 14) to allow for the gripping of small round objects such as nails; or to hold a narrow object firmly, such as the shank of a long saw blade, and to use the tool as a saw. In a preferred variation of the tool 30, each jaw 36 and 38 is provided with a sharp cut-away portion 120. In another not shown variant of the tool 30, different cutting edges may be provided.

Referring now to fig. 15-18, the lower handle, i.e., the front end 64 of the lever 34, is preferably attached by fasteners such as screws 122 to a thrust block 124 that is part of a jaw moving apparatus that includes the carriage assembly 74. The thrust block 124 is made of metal and is preferably made by metal die casting, but may be made in other ways.

A detent spring 126 made of thin spring material is overlapped at its central portion by the thrust block 124 with the inner surface of the rear portion 62 of the lower handle 34, and a pair of parallel side portions of the detent spring 126 extend from the central portion immediately adjacent to respective sides of the thrust block 124, as shown in fig. 11, 15A and 18. A pair of detent flanges 128 are formed on the sides of the detent spring 126 and face inwardly toward each other and are aligned with each other to resiliently grip the heel 54 of the lower jaw 38 and fit within the detent recess 130 to connect the front end of the lower handle 34 to the heel 54 in an easily releasable manner.

A pair of coaxial pivot arms 132 are provided on the thrust block 124 and are positioned on either side of the thrust block 124 and extend laterally toward the inner surface of the adjacent side 73 of the lower handle 34, as shown in fig. 18, to serve as jaw levers in the jaw moving arrangement to connect the thrust block to the carriage assembly 74.

Thrust block 124 has a concave forward face 134 and root 54 has a convex aft face 136. The two surfaces 134 and 136 are preferably cylindrical and have nearly equal radii so as to slidably and concentrically fit together to allow the thrust block 124 to rotate relative to the root 54 about an axis of rotation 138 extending transversely of the tool 30.

When the lower handle 34 is engaged with the heel 54, the detent spring 126 holds the heel 54 in addition to the thrust piece 124, while the surfaces 134 and 136 are in a mating relationship with each other to enable relative rotation about the axis 138. The locking pin flanges 128 are preferably positioned such that the distance between their centers is slightly less than the distance from the axis 138 to the concave surface 134 of the thrust block 124 so that the camming action of the pocket 130 on the locking pin flanges 128 will hold the surfaces 134 and 136 against one another when the locking pliers are in use.

The detent spring 126 can flex under the camming action of the recess 130 to disengage the detent flange 128 from the recess 130 simply by rotating the lower handle 34 counterclockwise from the position shown in figure 9 and past the position shown in figure 8A. The leading edge 140 of the rear portion 62 will straddle the heel 54 and meet the lower jaw 38 at 142 so that continued rotation using the heel 54 as a fulcrum allows the lower handle 34 to flex away from the heel 54 under the camming action of the recess 130.

Jaw adjustment and locking

The bracket assembly 74, which is part of the jaw moving apparatus, can be connected to the thrust block 124 by snapping each pivot arm 132 into a corresponding slot 144 in each bracket 86 at the forward end 82 of the bracket assembly 74. In one method of assembly, after the brackets 86 are first installed in the opposite sides of the thrust block 124 and the pivot arms 132 snap into the slots 144, the pins 76 may be inserted through one of the slots 78 into the holes 90 in the brackets 86 from the outside of the upper handle 32 and through the bracket block 88.

In another construction (not shown), the bracket block 88 may be mounted to the bracket 86 by a separate fastener, and the pin 76 may be removably mounted or may even be formed as a spring-loaded pin to completely separate the handles 32, 34 from one another.

The rear end 80 of the carriage assembly 74 is longitudinally movable along the upper handle 32 of the folding multifunction tool 30 within the confines of the slot 78 with the opposite end of the pin 76 engaging the slot 78. Movement of the rear end 80 is also limited by the position of the front end 146 of the adjustment screw 148, which limits rearward movement of the carriage block 88.

As shown in FIG. 19, the threads of the adjustment screw 148 engage threaded bores 152 in an adjustment block 154 mounted to the rear end of the upper handle 32. Adjustment block 154 may be made by metal die casting and retained by a fastener such as set screw 156. set screw 156 fits into a boss 155. boss 155 extends from adjustment block 154 and through a corresponding hole in rear portion 58. Axial forces are transmitted from the adjustment block 154 to the upper handle 32 by way of the boss 155, the screw 156 and a pair of ears 158, the ears 158 forming part of the adjustment block 154 and bearing against a respective one of the cut-out vertical surfaces 160 on each side 71 of the upper handle 32.

When the upper handle 36 is in the deployed position and the lower handle 38 is in the operating position, and the heel 54 cooperates with the thrust block 124 such that the front end 64 of the lower handle 34 is connected to the heel 54 of the lower jaw 38, the jaw control device will control the position of the lower jaw 38 relative to the upper handle 36. Movement of the lower handle 34 to which the thrust block 124 is attached will cause the pivot arm 132 to move relative to an imaginary line of force action 162 extending from about the axis of rotation 138 to about the axis of rotation of the pin 76. it will be appreciated that the actual location of force application in the jaw control arrangement will depend primarily on contact between the surface 134 of the thrust block 124 and the surface 136 of the root 54, and on the resolution of the force on the end 146 of the adjustment screw 148, the outer surface of the bracket block 88, and the inner surface of the handle 32. As the pivot arm 132 rides in the end of the elongated hole 144 adjacent the rear end 80 of the bracket assembly 74, as the central axis 164 of the pivot arm 132 approaches the imaginary line 162, the heel 54 is pushed away from the pin 76 by the thrust block 124 and thus pushes the lower jaw 38 to rotate about the jaw pivot shaft 52 toward the upper jaw 36.

When the handles 32 and 34 are separated and the jaws 36 and 38 are open to each other, the central axis 164 is located on the side of the imaginary line 162 proximate the lower handle 34. When the center axis 164 of the pivot arm 132 is located on the imaginary line 162, the distance between the upper and lower jaws 36 and 38 is at a minimum determined by the particular position of the front end 146 of the adjustment screw 148. As the lower handle 34 continues to rotate about the rotational axis 138 toward the upper handle 32, the central axis 164 will traverse the imaginary line 162 a small off-center distance. In this position, the stop arm 92 will contact the positive stop 84, as shown in FIGS. 9, 10 and 15, with little relaxation of the pressure between the jaws 36 and 38 and the object held therebetween. Thus, the tool 30 provides an eccentric locking pliers whose jaws can be folded into a compact configuration. The force used to push jaws 36 and 38 apart from each other is transmitted through the jaw control device and pushes stop arm 92 toward limit stop 84, thereby maintaining the off-center relationship of jaws 36 and 38. To release the grip of the jaws 36 and 38, the handles 32 and 34 need only be separated from each other far enough to move the central axis 164 back off-center toward the lower handle 34.

The spacing between the outer ends 112 and 114 of the jaws 36 and 38 can be increased by rotating the adjustment knob 40 to move the adjustment screw 148 rearwardly. The adjustment screw may also serve as an extension of the upper handle 32, thereby providing the upper handle 32 with a greater lever length when the jaws 36 and 38 are further apart.

It will be appreciated that the forces urging the lower jaw 38 toward the upper jaw 36 are compressive forces that are transmitted from the rear end 45 of the upper handle 32, through the adjustment block 154 and adjustment screw 148, through the front end 146 of the adjustment screw 148, through the intermediate assembly 74, through the bracket block 88, pin 76, bracket 86, the rear end of the elongated hole 144, and pivot arm 132 to the thrust block 124, which are then transmitted by the thrust block 124 through the surfaces 134 and 136 in contact with each other to the root 54 of the lower jaw 38. Due to the geometric relationship between the thrust block 124 and the rest of the jaw moving device, the attachment of the lower handle 34 to the thrust block 124 will never require the application of a significant force and thus the screw 122 need not be too large.

As shown in fig. 19, when the tool 30 is in the compact folded shape, the rotating arm 132 is located at the front end of the long hole 144. As can be seen in fig. 2, this allows the stop arms 92 to slide into the space defined by the slot between the sides 73 of the lower handle 34 without engaging the limit stops 84, the limit stops 84 fitting in the U-shaped area of the gap 86 alongside the stop arms 92. Referring also to FIG. 19, when pivot arm 132 is positioned forward of slot 144 and bracket assembly 74 is moved to forward end 53 of upper handle 32 such that pin 76 is moved rearward of the forward end of slot 78, the end of upper handle 32 can be aligned with the end of lower handle 34 and thrust block 124 is assembled adjacent to rear surface 106 of upper jaw 36. Jaws 36 and 38 are positioned between brackets 86, and brackets 86 extend against cheek plates 100 and 102 at forward end 82 of bracket assembly 74.

Once the jaws 36 and 38 are in the position shown in FIG. 6, the alignment just described above can be achieved without any special action by simply moving the handles 32 and 34 to the shape shown in FIG. 2. While some of these designs and configurations are complex, most of the movement and positioning of the various components is automated or intuitive to the user during tool use.

As shown in FIG. 11, a lug 168 projects outwardly from one of the brackets 86 toward the inner surface of the adjacent side 73 on the lower handle 34 and presses against the inner surface with sufficient friction to maintain the brackets 86 in the folded position in the lower handle 34 to hold the upper and lower handles 32 and 34 together when the tool 30 is in the compact folded configuration. The lug 168 may be formed by pressing the left bracket 86. The right bracket 86 may have a hole 170 for small radius bending of the wire and providing access to the adjustment lug 168 after assembly of the tool 30.

As shown in Figs. 19-21, adjustment block 154 defines a rectangular retention cavity 172 therein, the open side of which faces inwardly of the slot defined by lower handle 34. A projection 174 on the lower handle 34 extends into the cavity 172 to laterally and longitudinally retain the lower handle 34 relative to the adjacent upper handle 32 when the tool 30 is in the compact, folded configuration. It will be appreciated that the retention cavity 172 need not have any particular shape, but that the cavity 172 and the projection 174 preferably have substantially the same size and shape.

The protruding portion 174 may be, for example, a portion of the base of some folding tool blade carried on the blade spindle 42, i.e., tang 210, and preferably a portion of tang 210 of phillips head screwdriver 176, as shown in fig. 1. The phillips head screwdriver 176 is shaped so that it can be made by metal die casting, but other machining methods can be used.

Referring also to FIG. 19, it can be seen that a retaining spring 178 is mounted in the upper handle 32, with the base of the retaining spring located between the adjustment block 154 and the inner surface of the rear portion 58, and the retaining spring 178 is held in place by the set screw 156. An outer end of the retention spring 178 extends through a bore 180 defined by the adjustment block 154 and presses against the surface of the adjustment screw 148 to prevent inadvertent movement of the adjustment screw 148 and thus removal from the threaded bore 152 when the tool 30 is not in use and to prevent undesirable changes in the adjustment position of the jaws when the tool 30 is in use.

The portion of the adjustment block 154 nearest the rear end 45 of the upper handle 32 defines a tool head drive socket, such as preferably but not necessarily a hex socket 182, the smallest dimension of which is at least slightly larger than the outer diameter of the threads 150 of the adjustment screw 148, although the threads 150 may be formed to some extent in the wall of the tool head drive socket. The tool bit drive socket is sized to receive a shank of a tool bit, such as a hex shank 184 aligned with the open end of the socket 182 as shown in fig. 20. The outer end of the retention spring 178 extends through a wall of the sleeve 182 to press against a tool bit shank located in the sleeve 182. The spring 178 is preferably positioned relative to the length of the sleeve 182 such that its outer end may extend slightly into a latch slot 186 defined by the shank 184 to retain the tool shank 184 in the sleeve 182.

It will be appreciated that engagement of the projection 174 in the cavity 172 maintains the upper and lower handles 32 and 34 in alignment with one another when the tool 30 is used to rotate a tool head with the shank 184 inserted into the socket 182.

Locking mechanism for folding tool blade

Referring to fig. 22-24, the aforementioned locking mechanism is explained in detail below. As can be seen in FIG. 22, an opening 188 is defined on the outer side of the lower handle 34, i.e., the rear portion 62, adjacent the rear end 44, and a remaining portion of the rear portion 62 forms an elongate spring 190 that extends axially into the open area of the opening 188 relative to the lower handle 34 from a remaining cross bar 191 on the rear portion 62. The locking bar 46 has a pair of ears 192 that are each closely positioned along the inner surface of the side 73 of the lower handle 34, thus spanning the spring 190. Ear 192 defines a co-linear aperture for receiving pivot pin 48, and pivot pin 48 extends transversely of lower handle 34 through the co-linear aperture in side 73 and the aperture in ear 192. As shown in FIG. 23, the locking bar 46 has a flange 193 at its rear end, and when a tool blade, such as the combined file and screwdriver blade 194, is rotated about the blade pivot 42 to the extended position, the flange 193 rides over the free end of the spring 190 and slightly bows the spring 190 inwardly relative to the lower handle 34.

In addition to the file 194 with the straight screwdriver, other tool blades may be provided, such as a small size straight blade screwdriver 196 combined with a bottle opener, a medium size screwdriver 198, a cutting blade 200, and the aforementioned crosshead screwdriver 176.

In order that adjacent blades do not carry one another, the tool blades are preferably spaced from one another along the blade pivot axis 42 by shims (not shown) that are disposed within the handle 34 and are not rotatable about the axis 42. A short cable suspension loop 201 made of thin metal sheet is arranged between the file 194 and the combined blade 196 of the small screwdriver and the bottle cap opener. It will be appreciated that the lanyard hanger 201 need not be located at this location, but that it may be mounted at this location simply because the screwdriver 196 is small in size and may be reduced in thickness, thereby providing suitable space for the lanyard hanger 201 to be positioned along the small gauge screwdriver 196. The preferred shape of the lanyard suspension loop 201 is symmetrical with respect to an imaginary line 203 shown in fig. 23, thereby simplifying the assembly process of the tool 30 and allowing it to be rotated into the handle when not in use.

The small 196 and medium 198 drivers are preferably flat on their sides facing away from each other and beveled on their surfaces facing each other and adjacent the centrally located phillips head driver 176 to give the edges of each driver 196 and 198 the desired thickness to provide space for the phillips head of the phillips head driver 176 between them.

Each folding tool blade 176, 194, 196, 198, and 200 has a tang or base 210, respectively, and each tang or base 210 has a corresponding hole 214, respectively, for fitting closely through the blade pivot shaft 42 to enable each blade to rotate about the blade pivot shaft 42. The tang or base portion 210 of each tool blade also has a corresponding notch 202 for receiving a detent body 204 at one end of a detent arm 206 of the lock lever 46. On the other side of the rotational axis defined by ears 192 and pivot pin 48, the rear end of lock lever 46, lock lever release button portion 208, is disposed, preferably with non-slip surfaces on the outside, such as the parallel grooves shown in FIG. 22.

The tang or base 210 of each tool blade 176, 194, 196, 198, and 200 has an arcuate surface 216 on a side nearly opposite the notch 202 that is spaced approximately 160 and 180 degrees from the notch 202, and a cam lobe 218 is disposed adjacent to the arcuate surface. Between the cam lobe 218 and the notch 202 is a generally circular arc edge surface 220 having a radius greater than the circular arc surface 216 and preferably centered on the axis 42. Each tool insert has a convex or rear seating surface 217, respectively, to prevent each insert from moving too far into the groove of the lower handle 34.

Within notch 202 is an arcuate bottom surface 222 that meets an anti-fold surface 224 that extends inwardly from surface 220 and forms one side of notch 202. A support surface 226 is located opposite the anti-fold surface 224 and forms the other side of the score groove 202. The radial dimension 228 between the blade spindle 42 and the arcuate surface 216 and the radial dimension 230 between the blade spindle 42 and the arcuate bottom surface 222 of the notch 202 are preferably equal to each other and at least equal to the minimum dimension required for the tang 210 to have sufficient strength. The arcuate surfaces 216 and 222 are preferably circular and concentric with the tool spindle 42 to provide maximum radial dimensions 228 and 230 to meet the actual requirements, although other slightly different curves or locations for these surfaces are possible in accordance with the present invention.

As shown in fig. 24, retainer 204 includes a rear surface 232, a bottom surface formed by arcuate surfaces 234, and a front surface 236, which correspond to anti-fold surface 224, arcuate bottom surface 222, and support surface 226, respectively, of notch 202.

The button end 208 of the lock lever 46 overhangs the opening 188 on the rear portion 62 of the handle 34 as shown in fig. 23 and 24 such that the edge 238 of the opening 188 constitutes a positive stop to limit the range of motion of the button, lock lever release portion 208 of the lock lever 46 as shown in fig. 24. Typically, spring 190 against flange 193 will urge the lock lever to rotate to the position shown in FIG. 23, where retainer 204 is fully engaged in notch 202 of any tool blade that is ready for use in the deployed position.

When the rear end of the locking bar 46, i.e., the button portion 208, is fully depressed to the position shown in fig. 24, the rear surface 232 is disengaged from the anti-folding surface 224 of the notch 202, thereby allowing a deployed tool blade, such as the combined file and screwdriver blade 194, to freely rotate in a clockwise direction in fig. 24 to a folded position for stowage in the handle 34. Nevertheless, because of the greater length of the front surface 236, a portion thereof remains within the notch 202 and faces the support surface 226, thereby preventing the deployed tool blade from being excessively displaced about the blade pivot axis 42 in a direction away from its folded stowed position within the handle 34. Thus, although the button end 208 of the lock bar 46 is depressed, the blade is prevented from folding in its opening direction beyond its normal deployed position.

When the upper handle 32 is separated from the lower handle 34, if the button end 208 of the lock lever 46 is pressed to the restrained position shown in FIG. 24, any deployed tool blades can be rotated back to their stowed position in the lower handle 34 and the arcuate surface 234 of the detent body 204 will ride on the outer arcuate surface 220 of one or more of the tangs 210. When retainer 204 thus rides on curved surface 220 of one blade, the other blade is still free to rotate between a folded position within handle 34 and an unfolded position. Preferably, a small amount of lateral pressure is provided to maintain the folding blade in the folded position. Additionally, if one of the folding tool blades 176, 194, 196, 198, and 200 is moved out of its folded position in the lower handle 34, the cam 218 will lift the retainer 204 as that blade is moved out, thereby releasing the blade, which is now in the deployed position, to be able to rotate about the blade pivot shaft 42.

When all of the tool blades 176, 194, 196, 198 and 200, or other blades located in the lower handle 34 to replace these particular blades, are folded, the spring 190 acting on the flange 193 will push the retainer 204 against the arcuate surface 216 and against the cam 218 of the tang 210 of any blade that begins to rotate out of the folded position, thus holding the folded tool blades in their respective folded positions.

The arcuate surfaces 234 corresponding to the arcuate surfaces 216 and 222 provide space between the detent body 204 and the blade pivot axis 42 so that the tang 210 has sufficient material to meet strength requirements. This shape also provides space in the confined space of the compact folding tool to allow the anti-folding face 224 to be of sufficient size and to allow the front surface 236 to extend radially into the lower handle 34 a greater distance than the rear surface 232, thereby keeping the front surface 236 from disengaging from the support face 226 when the rear surface 232 disengages from the anti-folding face 224.

It should be noted that the phillips head screwdriver 176 in the folded position is angled up towards the edge of the side 73 of the lower handle 34 so that it can be lifted from the folded position by engaging the outer end of the phillips head screwdriver. Thus, the rear seating surface 217 of the score groove 202 on the phillips screwdriver tang 210 is disposed at a slightly different angle so that the phillips screwdriver 176 has its shank properly aligned with the lower handle 34 when in the extended position.

The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow.

Claims (42)

1. A folding hand tool (30) comprising:

(a) a first body member (32) having a leading end (53) and an inner side (66);

(b) a main jaw spindle (52) located at said forward end of said first body member;

(c) a first jaw (36) mounted on said first body member by said main jaw pivot shaft and movable about said main jaw pivot shaft from an extended position to a collapsed position;

(d) a second jaw (38) rotatable relative to said first jaw (36) and movable relative to said first body member (32) from an operative position to a folded position; and

(e) a jaw moving device extending between said first body member and said second jaw,

(f) characterised in that the first jaw (36) moves inwardly of said first body member when in the deployed position to the collapsed position, the second jaw (38) is adjacent said inner side (66) of said first body member when in the collapsed position, the jaw moving means comprising a jaw lever (124), said jaw lever (124) being releasably connected to and acting on said second jaw (38) when said second jaw is in said operative position, and being releasable from said second jaw when said second jaw is in said collapsed position to move the second jaw to the collapsed position by moving the jaw lever.

2. The folding hand tool (30) of claim 1, wherein said jaw moving means comprises a pair of legs (86) spaced apart from one another in a transverse direction of said hand tool, said jaws (36, 38) being positioned between said pair of legs when said jaws are in their respective folded positions.

3. The folding hand tool (30) of claim 1, wherein said first body member (32) includes a rear side (58) and a support seat (53) in said rear side, a portion (106) of said first jaw (36) abutting said support seat when said first jaw is in said extended position.

4. The folding hand tool (30) of claim 1, further comprising an operating lever (34) connected to said jaw lever.

5. The folding hand tool (30) of claim 1, wherein said jaw moving means is movable through a range of jaw moving positions to an over-center jaw locking position when said jaws (36, 38) are in their said extended and operative positions, respectively.

6. The folding hand tool of claim 5 further comprising a handle (34) defining a cavity opening toward said first body member, said jaw moving means comprising a bracket (86) having a stop arm, said handle including a limit stop (84) positioned in said cavity, said limit stop for blocking said stop arm and thereby establishing said over-center jaw locking position.

7. The folding hand tool (30) of claim 6, wherein said handle (34) includes a slot having a pair of sides, and said limit stop (84) is an inward projection on said sides.

8. The folding hand tool (30) of claim 6, wherein said bracket (86) is part of a bracket assembly (74) that includes a forward end (82) that is connected to said jaw lever (124) such that said jaw lever is capable of moving longitudinally from a first position in which said jaws are in said extended and operative position to a second position in which said stop arm is past said limit stop and said bracket assembly (74) is movable into said cavity of said handle (34) a greater distance than when said jaw moving means is in said over-center jaw locking position.

9. The folding hand tool (30) of claim 5, wherein said first body member (32) and said lever (34) are handles of said hand tool and are spaced apart when said jaw shifting means (74) is in said over-center jaw locking position.

10. The folding hand tool (30) according to claim 5, further comprising an adjustment mechanism (148, 154) in said first body member (32) and acting on said jaw shifting device (74) to move a portion of said jaw shifting device relative to said first body member (32) to provide an adjustable jaw spacing between said jaws (36, 38) when said jaw shifting device is in said jaw locking position.

11. A foldable hand tool (30) according to claim 1, having a compact folded configuration wherein said first and second jaws are each in said folded position and said first body member (32) is a first handle, said hand tool further comprising a second handle (34) attached to said jaw lever (124), said handles being parallel to each other and positioned side-by-side in close proximity.

12. The folding hand tool (30) according to claim 11, wherein said jaw moving means comprises a housing assembly (74) having a forward end connected to said jaw lever (124), said jaw lever being longitudinally movable along said housing assembly from a first position in which said jaws are in said extended and operative positions to a second position in which said folding hand tool is in said compact, folded configuration.

13. The folding hand tool (30) of claim 11, wherein said first handle (32) includes a rear end and has a block (54) at said rear end, said block defining a retention cavity (172) open to said second handle, and said second handle having a projection (174) associated with said retention cavity, said projection extending into said retention cavity when said folding hand tool is in said compact, folded configuration.

14. The folding hand tool (30) of claim 1, wherein at least one of the jaws (36, 38) includes a sharpened cutting edge (120).

15. The folding hand tool (30) of claim 1, wherein said first body member includes a rear side and a spring defined by a pair of openings in said rear side, said first jaw including a projection, said projection engaging said spring when said first jaw is in said extended position.

16. The folding hand tool (30) of claim 1, wherein said first body member (32) includes a slot having a pair of sides, one of said sides including an inwardly extending lug (104) that engages said first jaw (36) and prevents movement of said first jaw away from said folded position when said first jaw is in said folded position.

17. The folding hand tool (30) of claim 1, wherein the hand tool includes a spring (108) that engages said first and second jaws (36, 38) and rotates them in a direction away from each other.

18. A folding hand tool (30) comprising:

(a) a first jaw (36) mounted on a first support;

(b) a second jaw (38) movable relative to said first jaw about a jaw axis of rotation (50) during operation of said hand tool;

(c) a jaw moving device;

(d) a movable jaw control handle (34);

it is characterized in that the preparation method is characterized in that,

(e) said second jaw (38) having a root (54) spaced from said jaw axis of rotation; extending between said first support (32) and said root (54) of said second jaw, jaw moving means comprising a jaw lever (124) acting on said root of said second jaw, said movable jaw lever having a forward end connected to said jaw lever; the jaw control rod comprises a thrust body;

(f) said tool comprising a detachable joint connecting said thrust body to said root of said second jaw (38), said joint comprising a convex first portion (136) and a concave second portion (134) in contact with each other, said thrust body pressing on said root (54) through said joint and urging said second jaw (38) to rotate about said jaw rotation axis in a jaw closing direction when said tool is in use.

19. The folding hand tool (30) of claim 18, wherein said first support member (32) is a first handle.

20. The folding hand tool (30) of claim 18, wherein said convex first portion (136) is contained within said heel (54) and said concave second portion (134) is contained within said thrust body (124).

21. The folding hand tool (30) of claim 20, wherein said heel (54) includes a detent recess (130) and said adapter includes a detent flange (128) and a spring (126), said spring urging said detent flange into said recess when said urging member (124) is coupled to said heel through said adapter.

22. The folding hand tool (30) of claim 20, wherein said convex first portion (136) and said concave second portion (134) comprise cooperating generally cylindrical surfaces, each of said cylindrical surfaces having a respective cylindrical axis (138) parallel to said jaw axis of rotation (50).

23. The folding hand tool (30) of claim 18, wherein said detachable joint includes a spring-operated locking pin (128, 130) releasably connecting said thrust body (124) to said heel (54).

24. The foldable hand tool (30) according to claim 18, wherein said jaw moving means comprises a bracket assembly (74) extending between said first support member (32) and said pusher member (124) and urging said pusher member toward said heel (54) of said second jaw (38).

25. A folding hand tool, comprising:

(a) a first handle (32);

(b) a first jaw (36) connected to said first handle (36) and movable relative to said first handle (32) between an extended position and a folded position;

(c) a second jaw (38) connected to said first handle (32) and movable relative to said first handle between an operative position and a folded position;

(d) a second handle (34), characterized in that,

(e) said second handle having a front end removably connected to said second jaw (38) and an opposite rear end spaced from said second jaw; and

(f) the tool includes a holder assembly including a forward end rotatably connected to said second handle (34) between said forward end and said rearward end, said holder assembly having a rearward end connected to said first handle.

26. The folding hand tool (30) of claim 25, wherein said stand assembly (74) includes a pair of spaced apart legs (86) and said jaws (36, 38) extend between said legs when said jaws are in their respective folded positions.

27. The folding hand tool (30) of claim 25, wherein said rack assembly (74) includes a rack block (88) located at said rear end of said rack assembly and between said pair of racks (86) to laterally space said racks from one another.

28. The folding hand tool (30) of claim 25, wherein said rearward end of said bracket assembly (74) is longitudinally movable relative to said first handle (32) to provide a desired range of movement of said second jaw (38) relative to said first jaw (36).

29. The folding hand tool (30) according to claim 28, wherein the hand tool includes an adjustment screw (148) mounted in said first handle (36) and adjustably supporting said rear end (80) of said carriage assembly (74).

30. The folding hand tool (30) of claim 28, wherein said first handle (32) includes a slot (78) extending longitudinally thereof, and said bracket assembly (74) includes a transverse pin (76) engaged in said slot.

31. The folding hand tool (30) of claim 30, wherein said transverse pin (76) is selectively disengageable from said slot.

32. The folding hand tool (30) of claim 25, wherein the bracket assembly (74) comprises a bracket (86) having a sharpened U-shaped wire stripping section (99).

33. A folding hand tool (30) comprising:

(a) a handle (32) having an end (145) defining a tool head driving socket having a wall, an outward opening and an opposite inner end,

(b) wherein said wall defines an aperture through which said tool bit drive sleeve (182) communicates with the interior of said tool bit drive sleeve;

(c) an adjustment threaded bore (152) extending axially from said inner end of said tool head drive sleeve (182) relative to said handle;

(d) an adjustment screw (148) extending through said tool bit drive socket (182) and removably engaged in said threaded bore; and

(e) a retaining spring (178) mounted in said handle and extending into said interior of said tool bit drive socket (182) and abutting said adjustment screw (148) in said tool bit drive socket.

34. The folding hand tool (30) of claim 33, wherein said spring (178) extends into said tool bit driving socket (182) at a position such that said spring retains a tool bit received in said socket after said adjustment screw (148) is removed from said socket.

35. The folding hand tool (30) of claim 33, wherein said handle includes an adjustment block (154) connected to said first handle and defining said tool head drive sleeve (182) and said adjustment threaded aperture (152), said spring (178) including a base portion located between said adjustment block and said first handle member.

36. A folding hand tool (30) comprising a handle (34) and at least one folding blade (176, 194, 196, 198, 200), each blade having a base portion (210) defining a rotation aperture (214), said blade being rotatable about a pivot axis (42) mounted in said handle between respective extended and folded positions, said tool having a blade locking mechanism comprising a notch (202) in said base portion of said blade, a retainer (204) mounted on a lock release lever (146) movable about a lock axis (48) relative to said handle (34), and a spring (190) urging said retainer toward a position engaging said notch (202), characterized in that:

(a) said retainer (204) having a rear surface (232) and said notch (202) having a corresponding anti-fold surface (224);

(b) said retainer (204) having a front surface (236) and said score groove having a corresponding support surface (226), said front surface and said support surface having respective heights greater than the heights of said rear surface and said anti-fold surface; and

(c) the notch (202) has an arcuate bottom surface (222) spaced a radial distance from the axis of rotation (42), and the retainer has an inner surface (234) between the rear surface and the front surface and shaped to correspond to the bottom surface (222) of the notch.

37. The folding hand tool (30) of claim 36, wherein said handle (34) includes a portion (238) for preventing excessive movement of said latch release lever about said latch axis (48) to cause said front surface (236) of said retainer to disengage from said support surface (226) of said notch (202) when said latch release lever (46) allows said retainer (204) to move freely away from said pivot axis (42) far enough to allow said rear surface (232) of said retainer to disengage from said anti-fold surface (224) of said notch.

38. The folding hand tool (30) of claim 36, wherein said base portion (210) of said at least one folding blade (176, 194, 196, 198, 200) includes an anti-splaying shoulder (218) angularly spaced from said anti-folding surface (224) of said score groove (202) relative to said axis of rotation (42), and wherein said base portion of said blade further includes another arcuate surface (216) disposed adjacent said anti-splaying shoulder and extending angularly (42) about said axis of rotation and spaced from said axis of rotation by at least said radial distance (230).

39. The folding hand tool (30) of claim 36, wherein said handle (34) has a rear portion defining an opening (188), and wherein said tool includes a spring (190) extending into said opening and contacting said lock release lever (46), said spring urging said lock release lever in a direction urging said retainer (204) toward said spindle (42).

40. The folding hand tool (30) of claim 39, wherein a portion of said handle (34) is formed from sheet metal and said spring (190) is an integral part of said sheet metal.

41. A folding hand tool (30) comprising:

(a) a handle (32) including a member defining a tool head driving sleeve (182), said sleeve having a wall and defining an open outer end such that said sleeve is capable of receiving and driving engagement with a shank portion of a tool head, said sleeve having an inner end opposite said outer end; and

(b) a threaded bore (152) extending from said inner end and accessible through said outer end of said sleeve.

42. The folding hand tool (30) according to claim 41, comprising a retaining spring (178) attached to said handle, said wall of said tool head drive sleeve defining an aperture (180) through which the interior of said tool head drive sleeve is accessible, and a portion of said spring passing through said aperture and into said interior of said tool head drive sleeve.