WO2015065205A2

WO2015065205A2 - A lock mechanism

Info

Publication number: WO2015065205A2
Application number: PCT/NZ2014/000225
Authority: WO
Inventors: Andrew James Phillip RIDER; Garth Colin Keighley
Original assignee: Wedgelock Equipment Limited
Priority date: 2013-10-31
Filing date: 2014-10-29
Publication date: 2015-05-07
Also published as: WO2015065205A3

Abstract

A coupler used for the attachment of a work tool / implement to earth moving equipment. The coupler includes a locking mechanism (10) to prevent or restrict rotational movement of an actuator element R of the coupler. The locking mechanism (10) includes an engagement element (19) that is biased into engagement with one of a plurality of spaced apart engagement areas (12). The engagement element (19) can thereby engage with an engagement area (12) and be held therewith when the actuator element R is rotatably adjusted to attach the coupler to a work tool / implement.

Description

Title of the Invention

A Lock Mechanism

Related Application

This complete specification is after the provisional specification No. 61 7263 dated 31 October 201 3.

Background to the Invention

This invention relates to a lock mechanism and more particularly a lock mechanism for preventing or restricting rotation of one element relative to another element in a coupler used for the attachment of an implement to earth moving equipment such as an excavator.

A current design of coupler has a mechanical system that relies on the operator rotating a primary locking actuator onto one pin of a work tool/implement. A second pin is captured in a 'C shaped section opposing the locking force from the actuator.

During some operations serious vibration can be transferred through the primary actuator. This vibration can result in a cyclic loading that may cause the locking actuator to back off gradually and hence slowly retract the locking actuator. Depending on the size of the C shaped section in which the second pin is originally located, the locking actuator can retract far enough to allow the second pin to come free from its working position. This can either cause excessive work tool/implement movement or at worst the work tool/implement may swing dangerously.

Su mmary of the Invention

An object of the present invention is to provide a coupler used for the attachment of a work tool/implement to earth moving equipment, the coupler including a locking mechanism to prevent or restrict rotational movement of an actuator element in the coupler or at least provide the public with a useful choice.

Broadly according to one aspect of the invention there is provided a coupler used for the attachment of a work tool/ implement to earth moving equipment, the coupler including a locking mechanism to prevent or restrict rotational movement of an actuator element, the locking mechanism includes an engagement element that is biased by biasing means into engagement with one of a plurality of spaced apart engagement areas into one of which the engagement element can engage and be held therewith by the biasing means when the actuator element is rotatably adjusted to attach the coupler to a work tool/implement.

In the preferred form of the invention the engagement areas are coupled to and are moveable with the actuator element and the engagement element is located in a fixed location relative to the actuator element.

Preferably the engagement element has a suitably shaped surface that is engagable with the engagement areas of the actuator element. The shaped surface can be a substantially curved surface and in one form of the invention is provided by the engagement element being of a substantially spherical shape. The surface can be of other forms suitable for the end purpose and in other embodiments can be substantially "V" or "U" shaped for example.

In a preferred form the engagement element is movably mounted in a body. The body can include an open ended bore in which the engagement element is movably located. The biasing means forces the engagement element to the open end of the bore such that the shaped surface protrudes therefrom such that the shaped surface can engage with a surface of the actuator element.

In a preferred form of the invention the biasing means is a spring. Other biasing arrangements can be used, for example opposing magnets or an oil filled cylinder.

Preferably in one form of the invention the body has an external screw threaded portion whereby the body can be screwed into a threaded part of the coupler.

Preferably each engagement area effectively provides a ramp and to this end each engagement area can be in the form of suitably shaped groove or recess in a peripheral surface of the actuator element. In one form of the invention the engagement areas are spaced circumferentially about the surface of the actuator element at about 60° spacing's relative to a longitudinal axis of rotation of the actuator element. It will be appreciated that the spacing can vary depending on the number of engagement areas spaced about the surface of the actuator element.

According to aspects of the invention the biasing means and/or the combination of the biasing means and the inter-engagement of the engagement element and engagement area is such that a torque can be applied externally to the actuator element to adjustably rotate the actuator element. Brief Description of the Drawings

In the following more detailed description of one embodiment of the invention reference will be made to the accompanying drawings which form part of this specification and in which:-

Fig . 1 is a side cross sectional elevation view of a coupler incorporating a lock mechanism in accordance with the present invention,

Fig. 2 is an elevation view of the lock mechanism in accordance with the invention in conjunction with a rotatable element of the coupler shown in Fig. 1 ,

Fig. 3 is a view similar to Fig. 2 showing the lock mechanism in a locking position,

Fig. 4 is a section in an enlarged scale taken on line Bl -Bl on Fig. 3,

Fig. 5 is a view similar to Fig. 3 but with the lock mechanism between locking positions, and

Fig . 6 is a section in an enlarged scale taken on line B2-B2 of Fig. 5.

Descri ption of Preferred Embod iments of the Invention

In the foregoing and the following description reference will be made to parts of a coupler for attachment of a work tool/implement to earth moving equipment. This is by way of example of an application of the lock mechanism in a particular type of coupling. The invention is, however, not restricted to such an application.

According to the invention the lock mechanism is intended for prevention or at least restriction of rotation of a primary actuator of a coupler. This rotation can be caused by vibration occurring in the coupler under certain working conditions or loadings.

As shown in Fig. 1 . a coupler C of a known type has been modified to incorporate the locking mechanism 1 0 of the present invention. As is known to those skilled in the art the coupler C, as illustrated, has a cavity V (which as illustrated can be substantially "C" shaped) into which a pin (not shown) of the mounting means of a work tool/implement (also not shown) can be engaged.

As is shown in the accompanying drawings the cavity V is in part defined by a generally hook shaped element K that is a fixed part of the fabricated shaped cavity V. A knuckle (not shown) is pivotally mounted in the coupler C to rotate about an axle/shaft (not shown) in the opening 0. The knuckle is operable to capture the pin in the cavity V and release the pin from the cavity V.

The other pin of the work tool/implement is located in a recess S in the coupler C and is retained therein by a sliding wedge element W that is coupled to a primary actuator R. A threaded shaft element H of the actuator R is engaged in an internally threaded sleeve L that is coupled to the wedge W. The position of the wedge W can thus be adjusted by an operator rotating the primary locking actuator R.

The shaft element H extends through an end wall E of a body B. Spaced from the end E is a flange F. An annular portion P of the hook K is engaged on the shaft element H. The annular portion P is located between the flange F and an end wall surface of the end wall E as is shown in Fig.2. The shaft H can thus rotate in the annular portion P.

Consequently, if a vibration causes rotation of the shaft element H in the direction shown by arrow A in Fig. 2. the wedge W can become retracted and may result in the pin of the mounting of the work tool/implement to come free from its working position. This can cause excessive movement of the work tool/implement or at worst allow the work tool/implement to swing dangerously.

The locking mechanism 1 0 of the present invention has been devised to prevent the shaft element H rotating or at least restrict the extent of rotation of the shaft H so that the aforementioned excessive movement does not occur.

The direction of arrow A is by way of example. The direction A shown could be in the opposite direction depending on the coupler design.

Thus it will be appreciated by the skilled addressee that vibration could also cause rotation of the shaft H in the opposite direction as is indicated by the double headed arrow Al in Fig. 6. The locking mechanism 1 0 will also prevent or restrict movement of the shaft element H in this other direction of rotation.

According to the present invention engagement areas 1 2, that effectively form ramps, are coupled to the actuator element R. These can be formed in a surface of the actuator element R and can, for example, be small grooves or recesses 1 2 provided at circumferentially spaced positions on the outer surface 1 3 of the shaft H of the locking actuator R. In the preferred form the engagement areas 1 2 are spaced apart at substantially 60°.

In the preferred form of the invention an engagement element 14 is provided by a sprung loaded ball plunger 1 4 which is located in a fixed position relative to the actuator element R. The ball plunger 1 4 is thus preferably mounted in the annular portion P and can apply a load to the annular portion P at one of the grooves/recesses 1 2.

The ball plunger 1 4 includes a body 1 5 (see Figs. 4 and 6) with an open ended bore 1 6. A biasing element such as a spring 1 8 is located in bore 1 6. The spring 1 8 acts on an engagement element 1 9 that in part protrudes from the open end of the bore 1 6.

The engagement element 1 9 has at least a shaped protruding surface that can engage in a working relationship with the engagement areas 1 2. A substantially spherical ball shape (as shown) provides the most convenient means of inter-engaging with curved surface grooves/recesses 1 2 that effectively form ramps in the surface 1 3 of the actuator element R. It will be appreciated to those skilled in the art that other arrangements can be employed.

In a preferred form of the invention the body 1 5 can be screwed into a threaded bore 20 in the annular portion P. To this end a hexagonal cross section recess 21 (or a slot) is provided in the end wall of the body 1 5 to facilitate engagement of a hexagonal tool (or screw driver) so that a rotational action can be applied to the body 1 5 when screwing it into or out of the threaded bore 20.

A lock nut 22 (see Fig. 2) can be threaded onto the exterior of the body 1 5 to lock it in place in the bore 20. The skilled addressee will appreciate that other means for locking the body 1 5 in place can be employed.

Because the annular portion P is located in a fixed position (due to it being part of the hook shaped element K) the ball plunger 1 4 is in a fixed angular position relative to the shaft H. Consequently, the engagement of the ball 1 9 with a groove/recess 1 2 locks the shaft H against vibration induced rotation A.

The combination of force applied by the biasing means/spring 1 8, the ball 1 9 size (diameter Dl ), depth (D2) and size (e.g. radius Rl and width D3) of the grooves/recesses 1 2 combine to prevent or substantially prevent rotation of the shaft H due to the rotational force A set up by vibration. The groove/recess 1 2 is in effect a ramp where a reasonable amount of torque is required on the actuator R to overcome the force of the spring (biasing means) 1 8 in the ball plunger 1 4.

However, the torque required to overcome the locking mechanism 1 0 is low enough to allow the shaft H to be turned by a tool such as a ratchet or spanner. This is a requirement because the ergonomics of applying torque to the primary actuator R should not be compromised. The groove/recess 1 2 must be deep enough to allow the ball plunger 1 4 to apply the correct force and the width and radius of the groove/recess 1 2 must allow easy turning by the end user. Figures 3 and 4 of the drawings show the ball 1 9 located in a groove/recess 1 2 while Figures 5 and 6 show the ball 1 9 on the circumference of the annular portion P of the actuator R. Even if the adjusted angular position of the shaft H results in the ball taking up the position of Figures 5 and 6 (i.e. between grooves/recesses 1 2) the amount of rotation of the shaft due to vibration will only be small before the ball 1 9 locates in a groove/recess 1 2 and thereby lock the shaft H against further rotation due to vibration.

The present invention has been described and illustrated by way of a specific embodiment, and the embodiment has been described in detail in relation to a preferred form and application of the lock mechanism in a known form of coupler C. It is not the intention of the Applicant to restrict or in any way limit the scope of the invention to such detail.

The invention is thus open to modification. For example, the biasing arrangement could be formed by opposing magnets or by an oil filled cylinder.

While the shaped surface forming the engagement area is described herein as being a small groove or recess, e.g. curved surface, the surface can be of other forms suitable for the end purpose and in other embodiments can be substantially "V" or "U" shaped for example.

Additional advantages and modifications will be readily apparent to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative means of manufacture and method, and the illustrative example shown and described. Accordingly, departures may be made from such details without departure from the spirit or scope of the Applicant's general inventive concept.

Claims

Clai m s : -

1 . A coupler used for the attachment of a work tool/ implement to earth moving equipment, the coupler including a locking mechanism to prevent or restrict rotational movement of an actuator element, the locking mechanism includes an engagement element that is biased by biasing means into engagement with one of a plurality of spaced apart engagement areas into one of which the engagement element can engage and be held therewith by the biasing means when the actuator element is rotatabiy adjusted to attach the coupler to a work tool/implement.

2. A coupler as claimed in claim 1 wherein the engagement areas are coupled to and are moveable with the actuator element and the engagement element is located in a fixed location relative to the actuator element.

3. A coupler as claimed in claim 1 or 2 wherein the engagement element has a suitably shaped surface that is engagable with the engagement areas of the actuator element.

4. A coupler as claimed in claim 1 , 2 or 3 wherein the shaped surface can be a substantially curved surface and in one form of the invention is provided by the engagement element being of a substantially spherical shape.

5. A coupler as claimed in claim 4 wherein the surface is of a substantially "V" or "U" shape.

6. A coupler as claimed in any one of the preceding claims wherein the engagement element is movably mounted in a body.

7. A coupler as claimed in claim 6 wherein the body includes an open ended bore in which the engagement element is movably located.

8. A coupler as claimed in claim 7 wherein the biasing means forces the engagement element to the open end of the bore such that the shaped surface protrudes therefrom whereby the shaped surface can engage with a surface of the actuator element.

9. A coupler as claimed in claim 8 wherein the biasing means is a spring.

1 0. A coupler as claimed in claim 8 wherein the biasing arrangement is formed by opposing magnets.

1 1 . A coupler as claimed in claim 8 wherein the biasing arrangement is formed by an oil filled cylinder.

1 2. A coupler as claimed in any one of the preceding claims 6 to 1 1 wherein the body has an external screw threaded portion whereby the body can be screwed into a threaded part of the coupler.

1 3. A coupler as claimed in any one of the preceding claims wherein each engagement area effectively provides a ramp and to this end each engagement area can be in the form of suitably shaped groove or recess in a peripheral surface of the actuator element.

1 4. A coupler as claimed in claim 1 3 wherein the engagement areas are spaced circumferentially about the surface of the actuator element at about 60° spacing's relative to a longitudinal axis of rotation of the actuator element.

1 5. A coupler as claimed in any one of the preceding claims wherein the biasing means and/or the combination of the biasing means and the inter-engagement of the engagement element and engagement area is such that a torque can be applied externally to the actuator element to adjustably rotate the actuator element.

1 6. A coupler used for the attachment of a work tool/implement to earth moving equipment, the coupler being substantially as herein described with reference to the accompanying drawings