AU662547B2 - Grapple lifting implement - Google Patents

Description

OPI DATE 23/02/93 ACJP DATE 29/04/93 APPLN. ID 23253/92 l IIllllll llllll IIIIII IIIli PCT NUMBER PCT/AU92/00351 11111 Ii l111111 11111Il I AU9223253

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(51) International Patent Classification 5 (11) International Publication Number: WO 93/02010 B66F 9/18 A l (43) International Publication Date: 4 February 1993 (04.02.93) (21) International Application Number: PCT/AU92/00351 Published With international search report.

(22) International Filing Date: 15 July 1992 (15.07.92) Priority data: PK 7324 19 July 1991(19.07.91) AU6 5 4 7 (71)(72) Applicant and Inventor: LUCAS, Geoffrey, Wilfred [AU/AU]; R.M.B. 1090, Beechworth, VIC 3747 (AU).

(81) Designated States: AT, AU, BB, BG, BR, CA, CH, CS, DE, DK, ES, FI, GB, HU, JP, KP, KR, LK, LU, MG, MN, MW, NL, NO, PL, RO, RU, SD, SE, US, European patent (AT, BE, CH, DE, DK, ES, FR, GB, GR, IT, LU, MC, NL, SE), OAPI patent (BF, BJ, CF, CG, CI, CM, GA, GN, ML, MR, SN, TD, TG).

(54)Title: GRAPPLE LIFTING IMPLEMENT (57) Abstract The invention relates to a lifting implement incorporating a grapple device adapted to be mounted on a self-propelled lifting device and operable to pick up and hold loads such as logs, stumps, rocks, pipes, hay bales, wool bales and other bulk material for carrying and placement as required. The grapple device consisting of an upper jaw member (10) and a lower jaw member pivotally connected in a linkage system (16-23) is wholly mechanical in operation and does not require separate controls for the operation of the jaw members 10). The device is operable when tie lower jaw member is engageable under a load and when lifted the downwardly applied weight on the lower jaw member causes the upper jaw member through the operation of the linkage system (16, 23), to close onto the load which is then securely held between the jaw members 10) and may be lifted through the load lifting linkage of the lifting device. A manually operated release mechanism (27-30) is also provided.

I, 1 i~ -1- GRAPPLE LIFTING IMPLEMENT Fiel d of the Invention: THIS INVENTION relates to a lifting implement incorporating a grapple device adapted to be mounted on the three point linkage of a tractor or like machine and operable to pick up and hold non-fragile items such as logs, stumps, rocks, pipes, hay bales, wool bales and other bulk material for carrying and placement as required.

Whilst the implement of the present invention is primarily designed for fitment to the three point hydraulic linkage of a tractor, it could also be attached to and operable from other self propelled lifting devices such as forklifts, bobcats and front end loaders.

Background of the Invention: Grapple devices are known for attachment to tractors but such known devices comprise hydraulically operated grapple members requiring individual control means and subject to damage in use of the hydraulic mechanisms and the hydraulic fluid supply lines.

It is an object of the present invention to provide a grapple-type lifting implement which is wholly mechanical in operation and operable directly through a loadlifting system of a self-propelled lifting device such as the three point linkage of a tractor, without the necessity of separate controls for the operation of the grapple jaw members.

Is also an object of the present invention to provide manually operable release Smeans to disengage the grapple jaws to allow an item being carried to be dropped to Sreleased therefrom at a desired location.

Summary of the Invention: In accordance with the invention there is provided a lifting and grappling implement which does not require power operation for the g' ppling function, which implement comprises: a jib pole member having pivotal attachment means at a first end thereof for connection to a load-lifting linkage system of a self-propelled lifting device; I upper and lower grapple jaw members pivotally mounted on each other at a second end of the jib pole member; r y t -2the upper and lower jaw members being connected through a linkage system adapted to be actuated by the weight of a load engaged by the lower jaw member to bring the upper jaw member downwards to engage firmly and retain the load between the jaw members and the linkage system being connected between the lower jaw member, the upper jaw member and the jib pole member; and a manually operable jaw release mechanism pivotally mounted between the jib pole member and the upper jaw member and adapted to actuate the linkage system to open the upper and lower jaw members to release a load.

In order that the invention and its manner of performance may be more fully understood reference will now be made to an embodiment of the invention as illustrated in the accompanying drawings wherein: Description of the Drawings: Figure 1 is a perspective view of the lifting implement with a load being engaged therewith; Figure 2 is a perspective view of the lifting implement with the load lifted and securely engaged between the implement jaw members; Figure 3 is a view similar to Figure 2 and illustrating hidden parts in broken Figure 4 is a side elevation after operation of the overcentre toggle trip mechanism; Figure 5 is a side elevation of the jaws in the drop position after operation of the overcentre toggle trip mechanism; Figure 6 is a perspective view of the connection of the jaw members; and -p Figure 7 is a cross-sectional view taken along the line 7-7 of Figure 6.

SDescription of the Preferred Embodiments: Referring to the drawings the lifting implement of the embodiment illustrated comprises a jib pole member 5 for attachment at one end thereof to a load-lifting linkage system of a self-propelled lifting device. It will be appreciated that the attachment of the jib pole member may be to the 3-point hydraulic linkage of a tractor or may be adapted through suitable linkage members for attachment to other self propelled lifting devices such as forklifts, bobcats, front end loaders and the like.

At the other end of the jib pole member 5 a lower jaw member 8 is hingedly WO 93/02010 PCT/AU92/00351 -3attached by pivot pin 7 through cheek plates 9 of said lower jaw member 8 and an upper jaw member 10 is pivotally mounted on lower jaw member 8 through pivot pin 11 located between cheek plates 9 of the lower jaw member and extending through cheek plates 12 of the upper jaw member 10. Upper jaw member 10 is bifurcated at 13 at its outer end for engagement over lower jaw member 8 in a closed or near closed position of the jaw members 8 and 10 and is preferably serrated at 14 to enhance the gripping effect on a load to be engaged between the jaws. A handle is attached to upper jaw member 10 for the purpose of manual release of the jaws.

At the pivotal end of upper jaw member 10 there is located a tubular member 16 housing a compression spring 17 engageable by a pin 18 pivotally attached between link members 19 extending downwards for pivotal attachment at 20 on cheek plates 9 of lower jaw member 8. Compression spring 17 and link members 19 act as an overcentre spring linkage operable to hold the jaw members in the open position against gravity forces acting on the i jaw members. Tubular member 16 is preferably provided with lugs 6 to provide an enlarged bearing area for pin 18 in slots 21 of tubular member 16.

In order to or crate the lifting implement to drop or release a load there is provided a manually operable trip mechanism consisting of a screw threaded extensibly adjustable bar member 22 pivotally attached at one end by pin 23 between the lower ends of cheek plates 12 of upper jaw member 10. At its other end bar member 22 is hingedly attached to pivot pin 32 on one end of ayf wefeem= toggle 24 pivotally mounted at its other end on pedestal member 25 secured to jib pole member 5. Bar member 22 has a longitudinally extending flange member 26 which is latched in locked position by a flange member 29 extending from and secured at a substantially right angle to a rod member 27 pivotally mounted on a pedestal member 30 on the jib pole member and engageable above and against flange member 26. Attached to the other end of rod member 27 is a rope or the like 28 which, when pulled, releases flange member 29 from its latching engagement on flange member 26 and trips the oewem toggle 24 which swings over in a forward direction with attached bar member 22 under the weight of the load and the jaw members to allow the jaw members to swing down and move apart and drop or release a load held therebetween. In order to reset the grapple device in readiness to engage another load WO 93/02010 PCT/AU92/00351 -4the lower jaw member 8 is engaged with the ground or some other base structure and then moved in the reverse direction to the operation of the grapple device whereby actuation of the linkage system connecting the jaw members moves bar member 22 with toggle member 24 into its latching locked position beneath flange member 29.

In operation of the implement of the invention when a load is engaged by the lower jaw member and then raised, the movement of the lower jaw brings the upper jaw downwards at a ratio of 3:1 of movement of the lower jaw by reason of the linkage system between the jaws and the location of pivots 11, 23, 32 and 7, thereof whereby pivot 11 rotates around pivot 7 with pivot 23 being restrained by adjustable bar member 22 at pivot 32 causing rotation of upper jaw 10 to grasp a load between it and lower jaw 8. Whilst the overcentre spring mechanism 16, 17, 18, 19 and prevents gravity forces from closing the jaw members 8 and 10, and load on the lower jaw 8 that overcomes the overcentre spring mechanism generates by gravity a jaw closure force equal to approximately one half the weight of the load being applied to upper jaw 10 through the mechanical linkage system 7, 23, 22 and 32 thereby applying a compound force on the lower jaw 8 approximately equal to one and one half times the weight of the load being lifted and carried, thus the closure force is directly proportional to the weight of the load to be lifted. This closure or holding force is adequate to hold the load whilst the lifting device is travelling and to allow I20 operations on the load such as chain sawing a log. The grasping action of the jaw members is reversed when the load being carried is placed on the ground or at the point of placement by ieason of the lower jaw moving upwards which forces the top jaw away therefrom thereby releasing grasp of the load. In order to prevent excessive opening of the jaw members there may be provided a stop member 31.

Bar member 22 being longitudinally adjustable allows for adjustment of the attitude of the lower jaw member 8 to meet varying heights of operation of the implement in lifting a ioad from ground level or an elevated location thereabove such as the tray of a truck whereby lower jaw member 8 is positioned in a horizontal attitude when engaging the object to be lifted.

Jib pole member 5 may be formed, in known manner, so as to be extensible to allow access of the grapple device to locations beyond the normal reach of the implement and retractable for lifting heavy loads.

I

Claims (11)

1. A liftinz and erappline implement which does not require power operation f i i for the grappling function, which implement comprises: a jib pole member having pivotal attachment means at a first end thereof for connection to a load-lifting linkage system of a self-propelled lifting device; upper and lower grapple jaw members pivotally mounted on each other at a second end of the jib pole member; the upper and lower jaw members being connected through a linkage system adapted to be actuated by the weight of a load engaged by the lower jaw member to bring the upper jaw member downwards to engage firmly and retain the load between the jaw members and the linkage system being connected between the lower jaw member, the upper jaw member and the jib pole member; and t i J S. a manua the jib pole linkage syste

2. A lifting im] members are form connection and th cheek plates of the cheek plates of the

3. A lifting iml controlled linkage on the jaw membe lower ends on the spring member loc plates of the upper slots in *the upper ends of said pair o tubular member. Ad Ily operable jaw release mechanism pivotally mounted between member and the upper jaw member and adapted to actuate the m to open the upper and lower jaw members to release a load. plement according to Claim 1 wherein the upper and lower jaw ed with spaced apart cheek plates in the region of their pivotal e cheek plates of the upper jaw member are located within the lower jaw member and wherein a pivot pin extends through the upper and lower jaw members. ,lement according to Claim 2 wherein there is provided a spring- for holding the jaw members open against gravity forces acting rs comprising a pair of link members pivotally mounted at their outer side of the lower jaw member cheek plates, a compression :ated in a tubular member mounted on and between the cheek jaw member, the tubular member having diametrically opposed end thereof housing a pin member secured between the upper f link members and engaging against said spring member in said i Ii' *1 -6-

4. A lifting ement according to any one of Claims 1 to 3 wherein the upper jaw member is bifurcated at its outer end for engagement over the lower jaw member in a closed or near closed position of the jaw members.

A lifting implement according to any one of Claims 1 to 4 wherein said manually operable jaw release mechanism comprises a bar member pivotally attached at one end between the lower ends of the cheek plates of the upper jaw member. and at its other end to one end of a toggle pivotally mounted on the jib pole member and locked in position thereon by a trip mechanism.

6. A lifting implement according to Claim 5 wherein the other end of said toggle member is pivotally mounted on a pedestal member on the jib pole member.

7. A lifting implement according to Claim 5 or Claim 6 wherein said trip mechanism comprises a rod member pivotally mounted on a pedestal member at one end thereof and engaging the end of said bar member pivotally connected to said toggle member in the locked position and whereby actuation of said rod member releases its engagement with the end of said bar member and trips the toggle member to allow movement of the bar member to actuate said linkage system and cause the jaw members to swing down and move apart so as to release a load held therebetween.

8. A lifting implement according to Claim 7 wherein an angularly located flange on said rod member engages over a longitudinally extending flange on the bar member whereby lifting of the other end of said rod member as by a rope or the like Sconnected thereto actuates the trip mechanism.

9. A lifting implement according to any one of Claims 5 to 8 wherein said jaw release bar member comprises two screw threaded parts to provide adjustment of the length thereof so as to maintain a horizontal attitude of the lower jaw member at varying operating height: above ground level. A lifting implement according to any one of Claims 5 to 8 wherein the linkage system incorporates the pivotal connection of the jib pole member to the lower jaw member, the pivotal connection of the jaw members and the pivotal connections at each end of the bar member.

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11. A lifting implement according to any one of the preceding Claims wherein the jib pole member is extendible lengthwise to allow access of the grapple device to locations beyond the normal reach of the implement and may be decreased lengthwise for lifting heavy loads. i it DATED this 3rd day of October, 1994. GEOFFREY WILFRED LUCAS By His Patent Attorney. JAMES MURRAY CO. I 4 I 555 ~i ~x c;i I