GB2332417A

GB2332417A - Safety latches for an attachment device

Info

Publication number: GB2332417A
Application number: GB9827626A
Authority: GB
Inventors: Samuel Joseph Hughes
Original assignee: REDROCK ENG Ltd
Current assignee: REDROCK ENG Ltd
Priority date: 1997-12-16
Filing date: 1998-12-16
Publication date: 1999-06-23
Anticipated expiration: 2018-12-16
Also published as: GB2332417A9; GB9827626D0; IE981051A1; GB2332417B

Abstract

An attachment device for releasably securing implements to eg. an excavator or digger comprises a locking device (10 Fig.1) comprising a first recess 150 closeable by a first safety latch 104 eg. a substantially L-shaped latch, and a second recess 152 closeable by a second safety latch 134 eg. a pair of safety hooks or an elongate bar. In use, when the first latch is open the second latch is closed and when the second latch is open the first latch is closed. The locking device may be hydraulically or pneumatically operated. Such an attachment device has the advantage that only one mounting pin of an implement can be released at any one time, therefore said implement will be safely retained by at least one of the two mounting points when in use.

Description

2332417 ATTACITIMEINT DEVICE FOR EXCAVATING OR DIGGE-N G APPAIRLATUS The

present invention relates to an attachin, ent device for excavating or di,c,,cing apparatus.

Ptevicualyconsidered digga- bijr-- or othar iaplaraTts can be rsraubly certta: to ti--- arrn of an acarat-cr cr a digging c-cprat-s in crder to be eD-d when a different Slze bLrJet cr arother tml is regaired.

c Irh previcL:aly-cxsjder---i atbdiital cre 1 with tD reTcvc-ble pim Wrch are- md in =Jer to c over frcm ene atdchTent t3D cyiotirzr. 2e em-- of b-da-.ts ard to:ils:m tti,s,e[y is tme ccnsumxg and regilres a lot of effcrt.

A qiick attaclTmrt device h9s been ca-sidered, 9hjch Lq flmBd to the duper. ILth sj::h a device, the attachru can be enga:pd ard disengaged via tAc pu-s frcm the safety cf the cpercatirls seat. Ihis atb3Jnoi devim ocrmri9E--, tc hccks errjaga-ble wilh tNc pins, a tcp pin and a bottom pin fixed to each side of the bucket. When attaching a bucket, the top hooks are maneuvered so that they catch the top pin on the bucket 'nen the bucket is lifled and pivoted forward so that the bottom pin locates. The operator then locks the bottom pin from his seat via a hydraulic cylinder which operates a latch. The latch is shifted 20 forward and locks the bottom pin.

Plevicusly-c=-.,sj thpes cf qikk hit::hes Ine a safl, pin Wiich resbicts rronrnent ef mechanism locking the bottom pin. This stops the hitch opening accidentally. The fitting of this pin is vital to the safe operation of the unit. The problem with the safety pin is that 25 it is fitted manually and it totally relies on the operator getting out of the digger and fitting 0 it. One of the reasons operators use quick hitches is that they think they do not have to get out of the diaC"erto change a bucket or other implement. For this reason the safety pin is 00 often not fitted by the operator.

21s pre.-iclsly--cmmdEr,-d r-Ca:t device tLs the disaivuibeg--, that if the cperat= E73-11 to lleck the bDttan pin cr =idaTtal ly pushes the ytikh rele it, the br-kp-t or cittecilit:ii will fall cE of the e>ravating or digqinga- paratis. Clearly, this hw serior-_ saEety iffp3-icaticns.

Accordingly, an effbodiment of the present invention can provide an attachment device for releasably securing implements or tools, especially bucketsto the arm of an excavator or digging apparatus comprising a first connection which means enabling the attachment device to be mounted on the excavator or digging apparatus and second connection means for enabling the M attachment device to be engaged with an implement such as a bucket to the attachment device, the second connection rneans comprising a first recess and a second recess spaced apart therefrom, said first recess being closeable by a first locking device and said second recess being closeable by a second locking device for closing the second recess when the first recess is open so that in use, when the first locking device is open, the second locking device is closed and when the first locking device is closed, the second locking device is open.

In a preferred embodiment the locking device for locking the first hook is hydraulically or pneumatically operated.

Advantageously, the first locking device is a latch rotating about a horizontal axis which extends through the upper end of the latch, and the second locking device is mounted on the latch and guided in such way that it is shifted towards the opening of the second hook when the latch is moved in order to open the first hook.

Preferably the first locking device comprises a substantially L-shaped latch.

Optionally the second locking device consists of at least one elongate bar.

In a most preferred embodiment, the second hook is almost completely surrounding the pin and has an opening wide enough to conveniently catch the pin. A safety pin is operable to 0 further secure the second locking device in position.

Reference will now be made, by way of exarple, to the accnying drawings, in which:

Fig. 1 a perspazd-,e v:iew of an citbedi,Eti devdm, in a clisa state, am=diM tc) a fi eTb3climait ef the present irrvEnticn; Fig. 2 shows a cross-sectional view along arrow A in Fig. 1; Fig. 3 shows the cross-sectional view of Fig. 2 with the device in a secured position; Fig. 4 shows the cross-sectional view of Figure 3 with the attachment device engaging the top pin of a bucket; Fig. 5 shows the cross-sectional view of Figure 4 with the attachment device engaging the bottom pin of a bucket; Fig. 6 shows the cross-sectional view of Figure 5 with the bucket secured to the arm of the excavator; Fig. 7 shows the cros"ectional view of Figure 6 with the bucket in a position when the latch falls; Fig. 8 is a side view of an attachment device in a second embodiment of the p"mt invention, with the attachment device shown disengaged from the excavating or digging apparatus;:= t Fig. 9 is a side view of the attachment device of Figure 8, with the safety hook engaged with the top pin of a bucket (not shown); Fig. 10 is a side view of the attachment device connected on the boom of an excavatina or dia-ing apparatus, showing a first step in a sequence of connecting the c tto attachment device to a bucket, the safety hook bedng cpen to aLlew the caTEctkn ef the hitch to the top pin of the bucket; Fig. 11 is a side view of the next step in the sequence of attaching the attachment device to the bucket with the safety hook engaged with the top pin; C' Fig. 12 is a side view of the next step in the sequence with the top pin engaged in the recess but the L-shaped latch bffAre nct- Yet err-ogEd the Pdn t) clcse the reoess; Fig. 13 is a side view of the final step in the sequence with the L- shaped latch engaged to close the recess; and Fig. 14 is a side view showing the position of the bucket in the event of failure of the L-shaped latch and release of the pair of bottom pins of the bucket in which case the bucket is still connected to the attachment device at the top pin as shown in Figure 14.

In Figs. 1 and 2, reference numeral 10 denotes an attachment device erffiodying the invention. The attachment device comprises a pair of parallel side wall members 12, 1133, each side wall member including an outer side plate 2 and an inner side plate.3. The side C> 3 ti wall members 12 and 1) include a pair of spaced apart apertures 20, 22 for connec rig to two arm portions 14 and 16 (Fig. 4) of an excavator or digging apparatus (not shown). The attachment device 10 can be mounted on the arm portions 14 and 16 by inserting pins (not shown) through the apertures 20 and 22 and aligned apertures (not shown) on the arm portions 14 and 16. The side wall members 12 and 13 can be moved about the transverse axis extending through the aperture 20 by moving the arm portion 14.

Elements 24 and 25 form two pairs of hooks 26,26' and 28,28' which are fixed to the body member 12. The direction of openings of the hooks 26, 26'is different from the direction of opening of hooks 28, 28. Hooks 26, 26' opens towards the attachment device whereas the opening of hook 28, 28' is positioned in the opposite direction. The size of the openings is adapted to the size of a top pin 30 and a bottom pin 32 which are provided on each side of a bucket to be connected to the attachment device.

Fig. 2 shows how the top pin 30 and bottom pin 32 on each side of the bucket engage with the respective hooks 26, 26' and 28, 28'. A substantially L-shaped latch 34 is pivotably attached to the side wall members 12 and 13. The rotation axis 36 extends parallel to the rotation axes of apertures 20 and 22. The latch 34 can be moved until the recess defined by the hook 28,28' is closed and the bottom pin 32 is locked, as shown in Fig. 3). The rotation is achieved by a hydraulic cylinder 38, which is fixed to the body members 12 and 13). The hydraulic cylinder 3 8 can be operated from the operators seat in a well known manner.

Bars 40 and 41 are pivotably mounted on the latch 34. The bars 40 and 41 extend along the length of elements 24 and 25 towards the pair of hooks 26,26'. When the latch 34 is locking the bottom pin 32 in the pair of hooks 28,28', the other pair of hooks 26,26' is g 30 unlocked. When the substantially L-shaped latch 34 is moved in order to unlock the pair of hooks 28,28',sthe bars 40 and 41 are urged forward to close the other pair of hooks 26,26'.

This means that one pair of the hooks, either 26, 2Por 28,28', is always lock d when the c other one is unlocked as shown in Figures 2 and 3.

1 As shown in Figures 4 to 6 the bucket is attached to the arm portions 14 and 16 in a number of stages. In Fig. 4 arm portion 14 is shifted backwards, thereby lifting one end I of side wall members 12 and 13. The arm portions 14 and 16 are moved to engage the top pin 30 with the pair of hooks 26,26'. The substantially L-shaped latch 34 is in the locked position, i.e. the bars 40 and 41 are located such that the pair of hooks 26,26' are unlocked.

After engaging the top pin 30 on each side of the bucket, the substantially L-shaped latch 34 is moved to unlock the hooks 28,28'. The bars 40, 41 are thereby urged to lock the top pin 30 in the recess 50 defined by hooks 26,26'. The arm portion 14 is then shifted forwards and moves down the end of side wall members 12 and 13 in order to catch the bottom pin 32 in the hooks 28,29' (Fig. 5). After catching the second pin, it is locked by rotating the latch 3 4 by means of the hydraulic cylinder 3 8 into the locked position and the bucket 34 is secured to the arm 18 of the excavator (Fig. 6).

Once the bucket is attached to the arm of the excavating or digging apparatus with either the top pin 30 or bottom pin 32, there is always a pin 30, 32 in a locked position. Therefore the bucket cannot fall off at any time even when the substantially L- shaped latch 34 is accidentally rotated, i.e. when the operator accidentally operates the lever which releases the bucket at bottom pin 32. In this case the bucket will swing freely on the top pin 30 and the operator will know that there is a problem and stop work.

To unlock the top and bottom pins 30 and 332 the procedure illustrated in Figs. 4 to 6 is reversed. Firstly the substantially L-shaped latch _3)4 is moved to unlock the bottom pin 32 simultaneously resulting in the movement of the bars 40 and 41 so that they lock the top C pin 30. Then the arm portion 14 is shifted to disengage the pair of hooks 28,28'. In a last step, the latch 34 is moved back into its original position and top pin 3 3 0 can be released by moving the armi of the excavating or digging apparatus.

Z - -7 In a preferred embodiment the curvature of the pair of hooks 26,26' is such, that they hook on each side of the bucket when the top pin 30 is almost completely around the top pin j engaged. With such a curvature, the bucket is unlikely to fall off the arm even when pin 32 S fails when it is in the locked position. Top pin 30 at that time is not locked as it is shown in Fia 6. So, unless the bucket is pivoted right back so that bottom pin 32 is directly above pin 30 the bucket should hang on the pair of hooks 26,26'. This event though is much less likely than the case of accidental release as mentioned above.

A second embodiment of the attachment device of the present invention will now be described with reference to Figures 8 to 14 inclusive.

In Figures 8 to 14, the reference numeral 110 denotes an attachment device in a second embodiment of the invention. The attachment device 110 comprises a pair of parallel side wall members, each side wall member including an outer side plate 102 and an inner side plate 103.

Each outer side plate 102 includes two spaced apart apertures 120, 122. A mounting bushing 101 may be provided at each aperture 120 and 122. The bucket top pin 130 and bucket bottom pin 132 which are provided on each side of the bucket are also shown. The attachment device I 10 also includes a substantially L-shaped latch 134 which is pivotably attached to the device 110. The substantially L-shaped latch 134 operates to close a part of recesses 152 defined by a pair of hooks 128. The latch 134 is pivotally connected to a pair of safety hooks 104 by means of a hook link 106. The pair of safety hooks 104 operate to close the recess 150 defined by a pair of hooks 126. The attachment device 110 also includes a spacer plate 109, a hydraulic cylinder 1-3) 8 and a safety pin 111.

The attachment device 110 operates in a similar manner to that already described above except that the pair of safety hooks 104 operate to close the recess 150 defined by the pair of hooks 126, thereby locking top pin 130 provided on each side of the bucket as shown in Figure 9, rather than the bars 40 and 41 1 used to closes the recesses 50 defined by hooks 26,26' in the first embodiment of the attachment device 10 described above.

With reference to figures 10 to 13 inclusive, the operation of the attachment device I 10 will now be described. As shown in Figure 10, the safety hooks 104 are initially in the open position and the arm members 14 and 16 of the excavating or digg g apparatus are maneuvered so as to locate the top pin 130 on each side of the bucket in the recess 150 defined by hooks 126. When the safety hooks 104 are in an open position, the substantially L- shaped latch 134 is in the closed position, closing the recesses 152 defined by the hooks 128.

As shown in Figure 11, the safety hooks 104 are then moved into the closed position, thereby locking the top pin 130 in the recesses 150 defined by hooks 126. The closure of safety hooks 104 is operated by hydraulic cylinder 13 8 controllable by an operator from the cab of the excavating or digging apparatus. As the safety hooks 104 are moved forward into the closed position, the substantially L-shaped latch 134 is urged rearwardly through the hook link 106, thereby opening hook 128 and exposing recess 152 to the bottom pin 132.

As shown in Figure 12, bottom pins 132 are located in the recesses 152 defined by hook 128. As shown in Figure 13, the hydraulic cylinder is then activated to operate in the opposite direction urging the latch 134 to close over the bottom pins 132 thereby securing the bottom pin 132 in the recesses 152 defined by hooks 128. The safety pin 111 is then inserted so as to keep the latch locked to the bottom pin 132.

j Figure 14 shows the attachment device 110 in the event of failure of the substantially L-shaped latch 13)4 to lock the bottom pin 13)2. Since in such an event, the substantially L-shaped latch 134 is in the open position, then the safety hook 104 are in the closed position and the bucket is securely held by the top pin 130.

The hitch used in an embodiment of the present invention has a safety pin (11) but it also has the extra safety feature of allowing only one pin to be released at any one time i.e. bucket will always be held by either top or bottom pin on the bucket. Therefore if an operator was careless and neglected to fit the safety pin and there is an accidental release of the bottom pin or a hydraulic failure, the bucket or implement will not fall off, the worst that can happen is that it will swing from the top pin. Another benefit of this latching system is that when the top pin on the bucket or implement is being engaged by the previously-considered quick hitch, it is not always obvious that the top pin has been correctly seated. This is important because to engage the bottom pin the bucket or implement is usually raised from the ground and rotated so that the bottom pin drops into its position before locking. If for any reason the bucket is not correctly picked up on the top pin, it is in danger of falling off when the operator raises it from the ground to try and locate the other pin. This is an obvious hazard to safe working conditions is and practices. Uniquely with a system embodying the present invention, before the operator lifts the bucket or implements from the ground, the top pin is locked and therefore the bucket is secure. This is a procedure that must be followed as the top pin must be locked in order to allow the bottom pin access to be seated.

It will of course be understood that the invention is not limited to the specific details described herein, which are given by way of example only, and that various modifications and alterations are possible.

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Claims

Claims:

1. An attachment device for releasably securing implements or tools, especially I= buckets to the arm of an excavator or digging apparatus comprising a first connection means enabling the attachment device to be mounted on the excavator or digging apparatus and second connection means for enabling the attachment device to be C ZD enaaged with an implement suc h as a bucket to the attachment device, the second connection means comprising a first recess and a second recess spaced apart therefrom, said first recess being closeable by a first locking device and said second recess being closeable by a second locking device for closing the second recess when the first recess is open so that in use, when the first locking device is open, the second locking device is closed and when the first locking device is closed, the second locking device is open.

2. An attachment device according to claim 1 wherein the locking device for locking the first recess is hydraulically or pneumatically operated.

An attachment device according to claim I or claim 2, wherein the first locking device includes a latch pivotably mounted on the attachment device and the second locking device is fixed at the comer of the latch and guided in such way that it is shifted towards the opening of the second hook when the latch is moved in order to open the first hook.

4. An attachment device according to any preceding claim wherein the first locking device comprises a substantially L-shaped latch.

5. An attachment device according to any preceding claim wherein the second locking device includes at least one elongate bar.

6. An attachment device according to any preceding claim wherein the second locking device includes a safety hook.

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7. An attachment device according to Claim 6 wherein a safety pin is operable to further secure the second locking device in position.

8. An a attachment device substantially as herein described with reference to and as 5 shown in the accompanying drawings.

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