HITCH ASSEMBLIES

Abstract: A hitch assembly (10) for connecting implements such as a bucket (12) to a machine. The hitch assembly (10) includes a first connector assembly (25) which may be guided remotely for pivotal engagement with an implement (12) and a second connector assembly (26) which co-operates with the first connector assembly (25) to secure the implement (12) to the machine. The second connector assembly (26) may be secured to the implement (12) after pivoting the latter about the first connector assembly (25) to cause operative alignement therebetween.

Description: HITCH ASSEMBLIES This invention relates to improved implement hitching means. Conventional agricultural and/or earth working machines are provided with releasable connections or hitches for coupling implements thereto whereby a variety of implements may be coupled to any one machine. For example, a mechanical excavator may be used with buckets of various widths and capacities or with a pneumatic hammer. At present most hitches incorporate a pair of pins which have to be manually inserted through aligned apertures in respective eyes and hubs on the machine and on the implement to connect the latter to the machine. This can be a tedious operation due to the difficulty in forcing the pins through apertures which may not be aligned. Many attempts have been made to overcome this disadvantage by providing so called "quick hitches". These are adaptors which are generally fixedly secured to the machine and provided with spigots or sockets or the like which can be remotely coupled to corresponding sockets or spigots on the implement. While "quick hitches" have become popular for use with agricultural machines where the primary function of the hitch is to provide a towing and lifting connection for an agricultural implement, they have not gained widespread acceptance for use with earthmoving machinery. In such machinery the implement, such as a bucket, has to be coupled to the machine whereby it may be worked in any direction. For example a bucket may be pushed backwards or sideways to spread soil or the like or it may be moved forwards for digging. When elevated the bucket may be banged against its stops to jar remaining material from the bucket. Obviously a "quick hitch" connection for such earthmoving implements has to provide a very secure connection between the machine and the implement. Accordingly to date most "quick hitches" have been relatively complex and expensive and prone to malfunction in use. One prior "quick hitch" utilized spring biased latches to secure the implement to the hitch. The harsh environment in which such implements are worked often leads to premature failure of the latches. A further disadvantage associated with such presently available hitches is that they can be used only on non-standard implements modified to suit the particular latching means. Of course an operator will not use such "quick hitches" unless he can be sure as to their reliablility and provided he can readily couple and uncouple implements to his machine with a minimum of fuss. The present invention aims to alleviate the disadvantages associated with the aforementioned types of hitches and to provide a hitch assembly which will be reliable and efficient in use. Other objects and advantages of this invention will hereinafter become apparent. With the foregoing and * other objects in view, this invention in one aspect resides broadly in a hitch assembly for coupling an implement to a machine, said hitch assembly including a first connector assembly adapted for remote operation for engagement with support means on the implement and a second connector assembly connectible to the implement and co-operable with said first connector assembly to fixedly secure the implement to said hitch assembly. Preferably the first connector assembly provides a pivotal connection to the implement and suitably it includes a jaw-like mounting which can be remotely guided for engagement about a support member on an implement. The hitch assembly may be formed integrally with the machine or it may have mounting means thereon whereby it may be detachably secured to a machine. Preferably the second connector assembly is a socket assembly adapted for a pinned connection with the implement and suitably it is adapted to connect to one pair of the standard pin mounting eyes provided on an implement. Alternatively the second connector assembly may be in the form of a further jaw or jaw portion arranged opposite to the jaw-lik mounting of the first connector assembly and adapted to be held captive in the implement by a releasable stop bar or the like. It is also preferred that the jaw-like mounting on the hitch assembly is adapted to engage pivotably about a pin supported in the other pair of standard pin mounting eyes of an implement whereby the hitch assembly can be coupled to an implement provided with standard pin mounting eyes. In a preferred form the jaw-like mounting includes a pair of jaws each having a locating portion at the base of the jaw and which is adpated to engage snugly about the mounting pin. Suitably the jaw-like mounting also includes an outwardly divergent lead-in throat portion extending away from said locating portion. It is also preferred that the outwardly divergent lead-in throat portion extends away from the locating portion at the side thereof remote from said second conne'ctor assembly. In one embodiment of a hitch assembly according to this invention the mounting means on the hitch assembly is similar to the standard pin mounting eyes provided on an implement whereby the hitch assembly may be operatively connected in conventional manner to the machine in lieu of an implement. Of course this is not essential and if desired the hitch could form part of the linkage associated with the arm of an excavator or backhoe or the like. Alternatively it could be bolted or welded or otherwise connected to a machine or to its operating arm. In another aspect this invention resides in a method of connecting an implement to a movable mounting on a machine, the method including providing a hitch assembly on the movable mounting and having a first connector assembly remotely operable for pivotal engagement with an implement and a second connector assembly engageable with mountings on the implement when operatively aligned therewith; operatively engaging the first connector assembly with the implement; pivoting the hitch assembly about the first mounting assembly relative to the implement so as to operatively align the second connector assembly with said implement mountings, and forming the connection between the second connector assembly and said implement mountings. Preferably the connection between the second conector assembly and the implement is a pinned connection. It is also preferred that the relative pivotal movement between the implement and the hitch assembly is caused by actuating the movable mounting. Alternatively a screw jack or other adjustable means may be provided on the hitch or implement and operable to cause relative pivotal movement between the hitch and implement for alignment purposes. Also a screw jack or the like could be provided to form an adjustable stop for positioning the hitch and implement in alignment. In order that this invention may be more readily understood and put into practical effect reference will now be made to the accompanying drawings which illustrate a preferred form of hi ch assembly adapted for use on an excavator and wherein:- FIG 1 is a perspective view of the hitch assembly disposed adjacent the outer end of an excavator arm; FIG 2 is a perspective view illustrating the hitch assembly positioned for connection to a bucket; FIG 3 is a rear perspective view illustrating the hitch assembly connected to the bucket, and FIG 4 is a cross-sectional view illustrating the adjustable rear mounting on the hitch assembly. Referring to the drawings it will be seen that the hitch assembly 10 is in the form of an adaptor for performing quick connections between the outer end of an excavator arm assembly 11 and an implement such as the bucket 12. As illustrated standard excavator arm assemblies 11 are provided with a first mounting hub 13 in the outer end of the arm 14 and" a second mounting hub 15 at the free end of the linkage assembly 16 associated with the arm 14 and controlled for 5 pivotal movement thereabout by a hydraulic ram 17 (only an end portion of which is illustrated). The mounting hubs 13 and 15 normally locate between spaced pairs of eyes 1δf and 18r provided on spaced mounting flanges 19 on the bucket 12 and the connections between the mounting hubs 13 and 15 and the 10 respective eyes 18 are formed by inserting connecting pins through the eyes 18 and aligned mounting hubs. In accordance with the present invention the mounting hubs 13 and 15 are connected by pins to the hitch assembly 10 by passing pins 20 through the apertured side 15 plates 21 which extend upwardly from the body portion 22 of the hitch assembly 10. Suitably these plates 21 are spaced apart a distance equal to the distance between the mounting flanges 19 and the spacing of the front and rear apertures 23 and 24 therein likewise corresponds to the spacing of the eyes 20 i8f and I8r so that permanent but releasable connection between the hitch assembly 10 and the arm assembly 11 may be formed in conventional manner without modification to the arm assembly 11. In order that the hitch assembly 10 may be readily 25. connected to an implement, there is provided a first connector assembly comprising a pair of hook-like supporting members 25 fitted to the underside of the body portion 22 and extending forwardly thereof and an adjustable rear hub-like mounting assembly 26 adapted to be received between the rear eyes 18r 30 on the bucket 12. The rear mounting assembly 26 is provided with an eccentric bush assembly 27 to receive a pin 28 passed through the rear eyes 18 such that the pin 28 may be adjustably retained between the back eyes I8r as shown in FIG 3. 5 The hook-like mounting members 25 each include a C-shaped recess 29 adapted to seat snugly about a supporting pin 30 supported between the front eyes 1δf and a throat portion 31 which diverges outwardly to form a relatively wide inlet to the recess 29 to facilitate engagement of the jaws about the pin 30 by the machine operator when located remote from the bucket. As shown in FIG 5, the rear mounting assembly 26 includes a pair of spaced cylindrical housings 32 supported by side plates 33 which are fixed to the body 22 and which extend rearwardly from the mounting members 25. The housings 32 support an eccentric bush 34 which is restrained from axial movement therethrough by engagement of a grub screw 35 with a circumferential groove 36 in the bush 34. A further grub screw 37 is engageable with a selected one of a plurality of spaced indents ' 38 provided around the outer face of the bush 34 so as to hold the bush 34 in its selected rotational position relative to the housings 32. The bush 34 is provided with circumferentially spaced apertures 41 to enable a bar to be inserted into the bush to rotate -it for adjustment purposes. Also grease grooves and nipples are provided to maintain lubrication between the bush, the pin 28 and the housings 32. The grub screws 35 and 37 are each supported on a respective housing 32 and a collar 39 is provided to protect the head of the grub screws. Furthermore if desired spring loaded catches may be used in lieu of the grub screws . to facilitate ease of adjustment. After a period of time wear may create a loose fit between the hitch assembly 10 and an implement. The resultant wear clearance can be compensated for by adjusting the eccentric bush 34 until the desired tight fit is achieved. Furthermore the adjustment of the bush 34 enables the hitch assembly 10 to be fitted to a variety of implements in which the centre to centre distance of the pin eyes may vary from the standard within the range of adjustment of the bush 34. Of course other types of adjustment could be provided to clamp the mounting members about the mounting pins. For example, the hook like mounting members could be pivotally supported on the body 22 and pivotable by a wedge or cam or by hydraulic means or the like to cause the effective distance between the front and rear connector means to be varied and to clamp about the pins or to adjust the mounting means for use with implements having different pin mount spacings. In use the hitch assembly 10 is permanently connected to the arm assembly 11 so that implement changes can be made quickly and with minimum effort. Implements for use with the hitch assembly 10 remain standard, however the front supporting pin 28 may be fitted permanently in the front eyes I8f. A manually removable pin 30 is provided for passage through the rear eyes 18r and the eccentric bush 34. The connection with the implement is performed by moving the linkage assembly 16 to the dump position so that the jaws 31 are disposed for engagement about the pin 30. This is generally achieved by moving the arm 14 forwardly towards the machine and by adjusting the height of the arm to ensure that the jaws 31 pass about the pin 30. After this engagement has been achieved the arm 14 is raised such that the implement 12 is suspended from the supporting members 25. In this position the bucket 12 is freely pivotable about the front mounting pin 30 and it may be manually pivoted for alignment between the rear eyes 18r on the implement and the bush 34. Initial alignment is performed by the operator actuating the linkage mechanism 16 to crowd the hitch assembly 10 and thus pivot the rear mounting 26 towards operative alignment with the rear eyes 19. This crowding action is continued until the operator can gauge approximate alignment. Final alignment is performed manually by pivoting the freely suspended bucket 12 until the respective apertures are aligned to permit the pin 28 to be inserted. Only limited pivotal movement will be required for this purpose and this can be easily achieved by one person manipulating the bucket. It will be seen that the connection between the hitch assembly and the implement includes a conventional pinned type connection which co-operates with the front slide-on connection to positively secure the bucket 12 to the hitch assembly 10. Thus a very secure connection is formed such that the implement is capable of withstanding all the loads normally applied to the connection during operation of the machine. Furthermore the connection formed is a simple connection which does not rely on spring loaded latching means or other types of fastenings to ensure that an effective connection is maintained between the bucket or other implement and the hitch assembly. Preferably the pinned connection for the rear removable pin 30 includes a clip-on cap adapted to be secured about the projecting end of the hub 32 remote from the handle 40 which is provided to facilitate handling of the manually insertable pin 28. -The cap prevents dir -or grit entering the bearing surfaces and it may be packed with grease to prevent rust formation on the end of the pin. If desired the jaws may be formed with removable semi-circular bushes so that these can also be replaced when they become unserviceable through wear. The above description relates to a hitch assembly for buckets and implement having similar fittings for attachment to a machine and it has been given by way of illustration of the invention. Where the invention is adapted for use with a range of other types of implements it may be necessary of course to modify the mounting means on the hitch assembly to suit the particular range of implements being used. Such and other modifications and/or variations to this invention as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of the invention as is defined in the appended claims.

Claims: THE CLAIMS DEFINING THIS INVENTION ARE AS-FOLLOWS:- 1. A hitch assembly for coupling an implement to a machine, said hitch assembly including a first connector assembly adapted for remote operation for engagement with support means on the implement and a second connector assembly connectible to the implement and co-operable with said first connector assembly to fixedly secure the implement to said hitch assembly. 2. A hitch assembly according to Claim 1, wherein said first connector assembly connects pivotally to the implement to enable the implement to pivot into operative alignment with said second connector assembly. 3. A hitch assembly according to Claim 1 or Claim 2, wherein said first connector assembly is a jaw assembly engageable about a pivot pin on the implement. 4. A hitch assembly according to any one of the preceding claims, wherein said second connector assembly includes a hub assembly engageable between spaced eyes on the implement and connectible thereto by inserting a pin through said hub and said eyes. 5. A hitch assembly according to Claim 4-, wherein said hub includes an adjustable bush which may be adjusted to maintain a tight fit between the implement and the hitch assembly. 6. A hitch assembly according to any one of the preceding claims, wherein said hitch assembly is provided with mounting means for detachably securing it to a machine. 7. A hitch assembly according to Claim 6, and - 0- including a substantially rectangular body portion; spaced apertured plates extending away from one side of said body portion and forming said mounting means and the opposite side of the body portion supporting a hub adapted for a pinned connection to the implement and forming said second connector assembly and a jaw assembly having an outwardly divergent throat portion extending away from said hub assembly and forming said first connector assembly. 8. A method of connecting an implement to a movable mounting on a machine, the method including providing a hitch assembly on the movable mounting and having a first connector assembly adapted for remote operation for pivotal engagement with the implement and a second connector assembly engageable with a mounting on the implement when operatively aligned therewith; operatively engaging the first connector assembly with the implement; causing relative pivotal movement of the hitch assembly with respect to the implement so as to operatively align the second connector assembly with said implement mounting and forming the connection between the second connector assembly and the implement. 9. A method according to Claim 8, and including raising the hitch assembly so that the implement is freely suspended from said first connector assembly and then pivoting the implement for alignment with said second connector assembly. 10. A hitch assembly substantially as hereinbefore described with reference to the accompanying drawings.

Inventors: SPENCER DARYL JOHN, SPENCER GARY WILLIAM, SPENCER, DARYL, JOHN, SPENCER, GARY, WILLIAM
Applicants: SPENCER DARYL JOHN, SPENCER GARY WILLIAM, SPENCER, DARYL, JOHN, SPENCER, GARY, WILLIAM
Application year: 1985
Main classification: E02F3
IPC codes: E02F3