GB2423510A

GB2423510A - Counterweight structure for working machine

Info

Publication number: GB2423510A
Application number: GB0503669A
Authority: GB
Inventors: Duncan Andrew Smith; Finlay Andrew Wood
Original assignee: JCB Compact Products Ltd
Current assignee: JCB Compact Products Ltd
Priority date: 2005-02-23
Filing date: 2005-02-23
Publication date: 2006-08-30
Anticipated expiration: 2025-02-23
Also published as: GB0503669D0; GB2423510B

Abstract

A working machine (10, Fig 1) includes a counterweight structure 15, the counterweight structure 15 including a housing 16 secured relative to the working machine (10), and a plurality of weights 25a - 25e, each weight being selectively engageable with the housing 16. The housing has individual compartments 20a-e for each weight and each weight and the housing has openings for a locking pin 35 which is locked by passing a pin 46 through a keyhole slot in a fixture 41 and rotating against spring loading 53.

Description

Title: Working Machine

Description of Invention

This invention relates to a working machine including a counterweight structure. It will be appreciated by those skilled in the art that when driving a tractor or other similar working machine along a road particularly, that the steering performance of the machine may be detrimentally effected where the machine is carrying heavy working equipment, and/or is towing a trailer.

It is known to provide a counterweight at an opposite end of a machine to that which the working equipment and trailer is provided in an effort to improve the steering performance particularly of the front wheels of the machine.

Such counterweights may be provided with hooks and the machine may include a bar or the like onto which counterweights may be hooked. The number of counterweights may be selected depending upon the load which it is desired to counterbalance.

Such a mounting arrangement is undesirable because such counterweights can easily be disengaged from the bar for example upon the counterweight engaging an obstacle such as the ground. Thus counterweights may be lost.

According to a first of a first aspect of the invention we provide a working machine including a counterweight structure, the counterweight structure including a housing secured relative to the working machine, and a plurality of weights, each weight being selectively engageable with the housing.

The present invention enables a more secure mounting arrangement to be provided for weight.

The counterweight structure may be provided at one end of the working machine and the working machine may include working equipment at an opposite end of the working machine. Thus the counterweight structure will assist in balancing the working machine particularly but not exclusively during driving of the working machine during working operations.

In one example of a working machine, the working equipment is an excavating arm, but may be any desired working equipment as required.

Alternatively, the working machine may tow a trailer or working equipment at a rear end of the machine, the counterweight structure being provided at a front end of the machine. Thus the machine may be a trailer.

In each case, the housing may include a plurality of individual pods, each pod selectively receiving a part of a weight to mount the weight. Conveniently, the weights are all generally of the same configuration and are thus interchangeable.

The pods are preferably arranged in a generally horizontal array and the weights are each selectively engageable in a pod of the housing by a generally horizontal movement, e.g. from the one end of the working machine.

The pods may have generally horizontal openings, and the weights may each include a first part which is receivable in a pod, and a second part which includes a handle to facilitate manual carrying and handling of the weight.

To provide security against the weights becoming disengaged from the housing, each of the pods and the weights may have formations which interengage when the weights are received in their pods, to retain the engagement of the weights and the pods.

For example, the pods may each include side bottom and top walls, the top wall including at least one of an aperture and a locking formation, and the part of the weight which is received by the housing including at least one of a locking formation and an aperture, the locking formations and apertures interengaging upon receiving the first part of the weight in the housing.

A locking mechanism may be provided which is operative to lock each of the weights which are received in the housing relative to the housing. The locking mechanism may include a locking pin which is inserted relative to the housing and each of the weights so as to engage with each of the weights received in the housing, and the housing.

The housing may include a first end wall with a passage through which the locking pin is inserted, the passage in the first end wall being aligned with locking formations of each of the weights engaged with the housing, the locking pin in use being inserted through the passage in the housing end wall, and engaging the locking formations of the weights thus to lock the weights relative to the housing and prevent their intentional or unintentional disengagement therefrom.

Desirably the housing may include a second end wall opposite to the first end wall, the second end wall also having a passage aligned with the passage of the first end wall and the locking pin being inserted so as to extend between and into the passages of the first and second end walls and whilst engaging the locking formations afforded by the weights.

Although the locking formations of the weights may take any desired form, preferably the locking formations of the weights are passages through the weights.

To provide yet further security, the locking mechanism may have an interlock structure to prevent unintentional removal of the locking pin, e.g. due to vibrations as the working machine is used. The interlock structure may include an interlock member provided by the housing which interlock member has a key hole opening through which an axially extending locking part of the locking pin may pass as the locking pin is inserted through the key hole opening into the passage in the first end wall of the housing, with the locking part in a first radial orientation, the passage of the locking part back through the slot once the locking pin has been axially rotated to a locked condition being prevented, thus locking the locking pin relative to the key hole opening.

For example, there may be provided a locating recess to receive the locking pin when the locking pin has been inserted and rotated to its locked condition, there being a resilient element to bias the locking part into the locking recess.

In addition to the weights engaged with the housing, a working implement may be engaged with the housing, e.g. in a pod not occupied by a weight, the housing thus providing a useful mounting for such a working implement.

The working implement typically may be one of a towing hook, a tow ball, a winch or one a pair of tusks used for carrying an elongate work piece such as a log.

According to a second aspect of the invention we provide a counterweight structure including a housing having a mounting structure for mounting the housing to a working machine, a plurality of weights, each weight being selectively engageable with the housing.

The counterweight structure may have any of the features of the counterweight structure of the working machine of the first aspect of the invention.

Embodiments of the invention will now be described with reference to the accompanying drawings in which: FIGURE 1 is a perspective illustrative view of a working machine having a counterweight structure in accordance with the invention; FIGURE 2 is an illustrative perspective view to an enlarged scale and partially exploded, of the counterweight structure of the working machine of figure 1.

Referring to the drawings, a front end of a working machine, namely a tractor in this example is illustrated. The tractor 10 includes a chassis 11 which carries four ground engaging wheels 12, e.g. on axles, the two front wheels 12 which are shown, being steerable by a tractor operator.

It will be appreciated by those skilled in the art that when driving a tractor which carries heavy working equipment at the rear, such as an excavating arm, or when towing a heavy trailer for example, the steering performance of the working machine may be detrimentally effected. This detrimental effect may be compensated for by the provision of a counterweight structure 15 at the front of the working machine.

The counterweight structure 15 in the present example, includes a housing 16 which has a mounting structure provided by a pair of mounting lugs 17 and 18 by which the counterweight structure may be bolted to the machine 10, to the chassis 11 and/or a body 19 of the machine 10, or by means of which the housing 16 may otherwise be secured relative to the working machine 10.

The housing 16 provides a plurality of pods, five pods in this example indicated at 20a - 20e, which pods are arranged in a generally horizontal array at the front end of the tractor 10. Each of the pods 20a - 20e is provided by a pair of side walls 21, 22 (illustrated for pod 20e only), a top wall 23 and a bottom wall 24, the side walls 21, 22 of the three innermost pods 20b - 20d being shared, the pods 20a, 20e in this example each being generally of box shape. The mounting Jugs 18, 18 may be provided by extension of the side walls2l,22.

The counterweight structure 15 further includes a plurality of weights 25a - 25e, e.g. five weights 25a - 25e equivalent to the number of pods 20a 20e of the housing 16. Each of weights 25a - 25e may selectively be engaged with the housing 16 as hereinafter described to mount the weights 25a - 25e relative to the housing 16. The weights 25a - 25e each provide a counterbalance in an effort to improve steering performance of the tractor 10, particularly inbetween working operations when the tractor 10 may be driven along a road. For different weights of working equipment and/or different weights of a trailer to be towed, the counterweight requirement of the counterweight structure 15 may differ. Thus it may be decided by an operator not to engage five weights in the housing 16, but only selectively to engage a lesser number of weights in the housing 16. The weights 25 - 25 are each of identical construction and are fully interchangeable so that any of the weights 25a - 25e may be engaged with any of the pods 20a - 20e of the housing 16.

Each weight 25a - 25e has a first part 26 which is receivable within a selected pod 20a - 20e. Thus the first part 26 of the cweight 25a - 25e is also generally of box shape. The weights 25a - 25e further include a second weight part 27, which provides an integral handle 28 to facilitate carrying and handling of the weight 25a - 25e. The two weight parts 26, 27 including the handle 28, preferably are provided as a solid integral casting of a heavy material such as, for example only, cast iron.

It will be appreciated that the weights 25a - 25e may each be engaged with a pod 20a - 20e of the housing 16 by a generally horizontal movement, by inserting the first part 26 of the weight 25a - 25e into the selected pod 20a - 20e. Preferably the first part 26 of each weight 25a - 25e is provided with a locking formation which is indicated at 29. The locking formation 29 is provided by a "pip" in the weight casting and extends upwardly as the weight part 26 is received by a horizontal movement, within the selected pod 20a - 20e. Each pod 20a - 20e has in the top wall 23 thereof, an aperture 30, each provided in the example shown, by a through opening in the respective top wall 23. The aperture 30 is slightly larger in area than the area of the pip 29 on any weight 25a - 25e.

As the first part 26 of the weight casting is received in a selected pod 20a - 20e, by also undertaking a slight upward rotational movement of the weight 25a - 25e, the locking formation 29 may be received within the pod 20a - 20e and then as the weight 25a - 25e reaches its fully inserted condition, the weight 25a - 25e naturally will rotate relative to the selected pod 20a - 20e such that the locking formation 29 will be received within the aperture 30 in the top wall 23. Thus the weight 25a - 25e will be retained by the interengaging locking formation 29 and aperture 30 relative to the housing 16 to lessen the possibility of the counterweight 25 - 28 disengaging the housing 16. In another example, the locking formation 29 or similar could be provided by the housing 16 and the aperture 30 by a recess of the weight 25a - 25e.

The configuration of weights 25a - 25e and pods 20a - 20e, described above by way of example, provide a convenient and simple means of engaging a weight with the housing 16 and providing some security against a weights 25a - 25e inadvertently disengaging the housing 16.

To provide further, more permanent security against a weight 25a - 25e being removed from the housing 16, a locking mechanism is provided which is operative to lock each of the weights 25a - 25e relative to the housing 16 with which they are engaged. The locking mechanism includes a locking pin 35 which is insertable relative to the housing 16 and each of any weights 25a - 25e received in pods 20a - 20e of the housing 16, so as to engage with locking formations of each of the counterweights 25a - 25e thus engaged with the housing 16, and the housing 16 itself.

An end wall of the housing 16, e.g. side wall 22 of the end pod indicated at 20e in the drawing, is provided with a passage 36 through which the locking pin 35 may be inserted by an axial movement in the direction indicated by arrow A in the drawings. In this example, the first part 26 of each of the weights 25a - 25e includes a locking formation 37 with which the locking pin engages to lock the counterweight 25a - 25e in its respective selected pod 20a - 20e. The locking formation 37 which receives the locking pin 35 most conveniently is a passage which passage entirely through the first part 26 of each weight 25a - 25e and which, when the weight 25a - 25e is fully received in its selected pod 20a - 20e is aligned with the passage 36 in the end waIl 22 of the housing 16. Thus as the locking pin 35 is inserted in the direction of arrow A through the passage 36, the locking pin 35 may too pass through the passage 37 in the or each weight 25a - 25e which is received in a pod 20a - 20e of the housing 16.

Furthermore, the opposite end wall of the housing 16 indicated in the drawings at 22a, also includes a passage (not shown) which is aligned with the passage 36 in the first end wall 22, so that a leading end 38 of the locking pin 35 is in use, received in the passage in the second end wall 22a so as to extend between and thus span the entire width of the housing 16.

Thus each of the weights 25a - 25e, when the locking pin 35 is inserted, is prevented from being disengaged from the housing 16.

An interlock structure is also provided to prevent the unintentional removal of the locking pin 35, for example, in response to vibrations as the working machine 10 is operated.

The interlock structure includes a first interlock member 40 which is in use is secured relative to the first end wall 22 of the housing 16 in which the passage 36 is provided for the locking pin 35. The first interlock member 40 is of generally channel shape, having a base 41 and a pair of side walls 42. The side walls 42 space of the base 41 from the first end wall 22 for a reason hereinafter explained.

The base 41 of the first interlock member 40 has a keyhole opening 45. The locking pin 35 includes a radially extending locking part 46 towards its outermost end which does not pass into passage 36 in the end wall 22. With the locking pin 35 in an orientation such that the locking part 46 is aligned with slots of the keyhole opening 45, the locking pin 35 may be inserted into the housing 16 to engage the passages 37 of any weight 25a 25e received in any pod 20a - 20e, the locking.part 46 passing through the keyhole opening 45 to permit the locking pin 35 fully to be inserted. However, upon rotating the locking pin 35 when the locking pin 35 is axially fully engaged relative to the housing 16, to bring the locking part 46 to a orientation in which the locking part 46 cannot pass back through the key hole opening 45, the locking pin 35 will be retained in the passage 36 in the first end wall 22 and any passages 37 of weights 25a - 25e received in any of the pods 20a - 20e of the housing 16, and the passage in the second end wall 22a opposite the end wall 22.

The interlock structure shown in the drawings is yet more sophisticated in that a second interlock member 48 is provided, which in use is located between the base 41 of the first interlock member 40 and the first end wall 22, with there being a space between the first end wall 22 of the housing 16 and the second interlock member 48. Thus the second interlock member 48 may lie adjacent the base 41 of the channel shaped first interlock member 40.

Upon insertion of the locking pin 35, with the locking part 46 in a first orientation aligned with the slots of the keyhole opening 45 of the first interlock member 51, 52, the locking part 46 may be inserted too through aligned horizontal slots 49 of the second interlock member 48 fully to insert the locking pin 35. Between the locking part 46 and an end handle 50 of the locking pin 35, there are provided a pair of washers 51 and 52 with a coil spring 53 therebetween. The spacing of the locking part 46, washers 51, 52, spring 53 and handle 50 are such that the locking pin 35 must be inserted axially beyond its fully engaged position, to permit the locking part 46 to pass into the space between the second locking member 48 and the end wall 22 of the housing 16, to permit the locking part 46 to be rotated.

Upon such movement of the locking pin 35 beyond its fully engaged position, in the direction of arrow A, the spring 53 becomes compressed as the leading washer 51, 52 engages the base 41 of the first locking member 40, to permit the locking part 46 to pass through the horizontal slots of the second locking member 48. Once the locking pin 35 is rotated to bring the locking part 46 to an upright orientation, the spring 53 may assist in returning the locking pin 35 axially a small distance until the locking pin 46 is located in a locking recess provided in this example by one of a pair of vertical slots 55 of the second locking member 48 in which vertical slot 55 the locking pin 46 will be retained against rotation. Thus to release the locking pin 35 subsequently, first it is necessary to exert an axial force in the direction of arrow A, to move the locking part 46 back into the space between the second locking member 48 and the end wall 22, and permit the locking pin 35 to be rotated to bring the locking part 46 into alignment with one of the horizontal slots 49 of the second locking member 48 and the slots of the keyhole opening 45 of the first locking member, to permit the locking part 46 to be withdrawn through the aligned slots, so that the locking pin 35 may be released.

Various modifications are possible without departing from the scope of the invention. It will be appreciated that although in the example described, the counterweight structure 15 is provided at a front end of a tractor 10 or similar working machine, the invention may be applied to other working machines where there is a requirement for a counterweight structure which permits a selected number of counterweights and thus varying counterweight to be achieved. Thus in another machine, such a counterweight structure 15 may be provided at a rear of machine to counterbalance a load applied at a front of a machine 10.

It will be appreciated that where not all of the pods 20a - 20e of the housing 16 are occupied by weights 25a - 25e, that unoccupied pods 20a 20e may be used for other purposes. For example, it is envisaged that the housing 16 may provide a useful mounting for a working implement which has the equivalent of the second part 26 of the weights 25a - 25e provided thereon.

Thus a part of such a working implement may be received in a pod 20a - 20e for reliable mounting of the working implement, and retained, for example by a locking formation and aperture, like locking formation 29 and aperture 30 described with reference to the example, and by a locking pin 35 of a locking mechanism as described if desired.

One such working implement may be, for example, a towing hook, a tow ball, a winch or one of a pair of tusks which may be used for carrying an elongate workpiece such as a log, in an orientation generally transverse to the forward and reverse directions of movement of the working machine 10.

The weights 25a - 25e need not be of the configuration shown in the drawings but may be of any other desired configuration. It will be appreciated that the weights 25a - 25e are preferably fully interchangeable with each other. In the example shown, each weight has an upper overhang feature 55 which engages over the opening of a selected pod 20a - 20e with which the counterweight 25a - 25e is engaged, and similarly a lower overhang feature 56 which overhangs the opening of the selected pod 20a - 20e with which the weight 25a - 25e is engaged, and the weights 25a - 25e may have sideways engaging formations if desired (not shown), to interlock the second parts 27 of the weights 25a - 25e together as subsequent counterweights 25b - 25e are engaged with the housing 16.

Instead of each weight 25a - 25e having a passage 37 with which the locking pin 35 engages, any other desired formation with which the locking pin 35 may engage to prevent the removal of any weight 25a - 25e from the housing 16 whilst the locking pin 35 is engaged, may be provided.

In another example, the pods 20a - 20e need not be generally box shaped as described, but could be of other configurations. The pods 20a - 20e need not be provided in a horizontal array as described and shown, but may be provided in some other array and need not be immediately adjacent one another, but pods 20a - 20e may be provided spaced from one another. Any desired number of pods 20a - 20e may be provided as desired.

In the present example, when the housing 16 is mounted to the chassis 11 of the working machine 10 it will be appreciated from Figure 1, that the first side wall 22 and the first and second locking formations 40 and 48 are concealed by a side chassis part which is indicated at Figure 1 at 60. In the present example, that side chassis part 60 has a passage which is aligned with the keyhole opening 45, and the passage 36 of the first side wall 22 of the housing 16 to permit the locking pin 35 axially to be inserted into the passage 36 of the first side wall 22 and thus engaged with the passages 37 or other locking formations of each of the counterweights 25a - 25e engaged with pods 20a - 20e of the housing 16. In another implementation, no chassis part 60 may overlie the first side wall 20.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

1. A working machine including a counterweight structure, the counterweight structure including a housing secured relative to the working machine, and a plurality of weights, each weight being selectively engageable with the housing.

2. A working machine according to claim I wherein the counterweight structure is provided at one end of the working machine and the working machine includes working equipment at an opposite end of the working machine.

3. A working machine according to claim 2 wherein the working equipment is an excavating arm.

4. A working machine according to claim 1 wherein the machine tows a trailer or tows working equipment at a rear end of the machine, the counterweight structure being provided at a front end of the machine.

5. A working machine according to any one of claims 1 to 4 wherein the housing includes a plurality of individual pods, each pod selectively receiving a part of a weight to mount the weight.

6. A working machine according to claim 5 wherein the weights are all generally of the same configuration and are thus interchangeable.

7. A working machine according to claim 4 or claim 5 or claim 6 wherein the pods are arranged in a generally horizontal array and the weights are each selectively engageable in a pod of the housing by a generally horizontal movement.

8. A working machine according to claim 7 wherein the pods have generally horizontal openings, the weights each including a first part which is receivable in a pod, and a second part which includes a handle.

9. A working machine according to any one of claims 4 to 8 wherein each of the pods and the weights have formations which interengage when the weights are received in their pods to retain the engagement of the weights in the pods.

10. A working machine according to claim 9 wherein the pods each include side bottom and top walls, the top wall including at least one of an aperture and a locking formation, and the part of the weight which is received by the housing including at least one of a locking formation and an aperture, the locking formations and apertures interengaging upon receiving the first part of the weight in the housing.

11. A working machine according to any one of the preceding claims wherein a locking mechanism is provided which is operative to lock each of the weights which are received in the housing relative to the housing, the locking mechanism including a locking pin which is inserted relative to the housing and each of the weights so as to engage with each of the weights received in the housing, and the housing.

12. A working machine according to claim 11 wherein the housing includes a first end wall with a passage through which the locking pin is inserted, the passage in the first end wall being aligned with locking formations of each of the weights engaged with the housing, the locking pin in use being inserted through the passage in the housing end wall, and engaging the locking formations of the weights thus to lock the weights relative to the housing.

13. A working machine according to claim 12 wherein the housing includes a second end wall opposite the first end wall, the second end wall also having a passage aligned with the passage of the first end wall and the locking pin being inserted so as to extend between and into the passages of the first and second end walls and whilst engaging the locking formations afforded by the weights.

14. A working machine according to claim 12 or claim 13 wherein the locking formations of the weights are passages through the weights.

15. A working machine according to any one of claims 11 to 14 wherein the locking mechanism has an interlock structure to prevent unintentional removal of the locking pin, e.g. due to vibrations as the working machine is used.

16. A working machine according to claim 15 wherein the interlock structure includes an interlock member provided by the housing which interlock member has a key hole opening through which an axially extending locking part of the locking pin may pass as the locking pin is inserted through the key hole opening into the passage in the first end wafi of the housing, with the locking part in a first radial orientation, the passage of the locking part back through the slot once the locking pin has been axially rotated to a locked condition being provided thus locking the locking pin relative to the key hole opening.

17. A working machine according to claim 16 wherein there is provided a locating recess to receive the locking pin when the locking pin has been inserted and rotated to its locked condition, there being a resilient element to bias the locking part into the locking recess.

18. A working machine according to any one of the preceding claims wherein in addition to the weights engaged with the housing, a working implement is engaged with the housing.

19. A working machine according to claim 18 wherein the working implement is one of a towing hook, a tow ball, a winch or one a pair of tusks.

20. A working machine substantially as hereinbefore described with reference to and/or as shown in the accompanying drawings.

21. A counterweight structure including a housing having a mounting structure for mounting the housing to a working machine, a plurality of weights, each weight being selectively engageable with the housing.

22. A counterweight structure according to claim 21 having any of the features of the counterweight structure of the working machine specified according to any one of Claims 1 to 20.

23. A counterweight structure substantially as hereinbefore described with reference to and/or as shown in the accompanying drawings.

24. Any novel feature or novel combination of features described herein and/or in the accompanying drawings.