WO2021089879A1

WO2021089879A1 - Tractor hitch assembly

Info

Publication number: WO2021089879A1
Application number: PCT/EP2020/081531
Authority: WO
Inventors: David Doran; Mark Doran
Original assignee: Davdor Limited
Priority date: 2019-11-08
Filing date: 2020-11-09
Publication date: 2021-05-14
Also published as: GB201916281D0; GB2589838A

Abstract

A tractor hitch assembly (2) is for mounting an attachment such a baler or a digger arm on a tractor (1). The hitch assembly (2) is of two part construction comprising a first part (5) for mounting on the tractor (1) and a second part (6) for mounting on the attachment. Each part (5, 6) has means for mounting the part (5, 6) on the tractor (1) or on the attachment comprising a tractor mounting plate (7) and an attachment mounting plate (8) for bolting to the tractor (1) and to the attachment respectively. A connector assembly (10) for interconnecting the two parts (5, 6) comprises a male element (11) and a complementary female element (12) for reception of the male element (11). Retractable locking pins (14) on the male element (11) are releasably engagable within associated receiver sockets (15) on the female element (12) to releasably rigidly lock the male element (11) in engagement with the female element (12). The first part (5) of the hitch assembly (2) includes a pivot linkage to allow the connector assembly (10) to pivot in two mutually perpendicular directions. A turntable is rotatably mounted at an outer end of the first part (5) for rotating the male element (11) about a central longitudinal axis of the first part (5).

Description

“Tractor Hitch Assembly”

Introduction

This invention relates to a tractor hitch assembly and to a tractor incorporating the hitch assembly.

The invention particularly relates to a tractor hitch assembly for mounting an attachment on a tractor. The attachment may be a tool or implement such as a digger or a plough, or a trailer, baler or other apparatus that is used with tractors, For convenience throughout this specification the term “attachment” has been used to include all such tools, implements and attachments.

Various known hitch assemblies are disclosed in US 2011/0193320 A1, US 2006/0xx6625 A1, US 4131295 A, US 4077234 A, US 2420725 A, US 3891237 A, US 2006/0138745 A1, US 2010/117334 A1 and GB 2078079 A.

In conventional tractors typically a three-point linkage is provided at a rear end of the tractor for mounting such attachments on the tractor. These have worked well for many years. However, connecting attachments to and releasing attachments from the three-point linkage and connecting and releasing the associated hoses, etc. can be relatively time-consuming. There is also a safety aspect as it is sometimes necessary to climb on or between the tractor and attachment during engagement and disengagement of the attachment.

Further, tractors generally have a power pack comprising a diesel engine. Some attachments draw relatively high power from the diesel engine, however, much of the time a relatively low power is required by the tractor. Therefore the tractor operates under optimum running conditions for only a portion of the time and overall operating efficiency of the tractor is relatively low.

The present invention is directed towards providing an improved tractor and tractor hitch assembly. Summary of the Invention

According to the invention there is provided a tractor hitch assembly for mounting an atachment on a tractor, the hitch assembly being of two-part construction comprising a first part for mounting on the tractor and a second part for mounting on the attachment, each part having means for mounting the part on the tractor or on the attachment, and a connector assembly comprising complementary releasably interengagable formations on the two parts, the connector assembly comprising a male element and a complementary female element for reception of the male element, and a lock to reieasably rigidly lock the male element in engagement with the female element.

In one embodiment of the invention the hitch assembly includes a pivot linkage to allow the connector assembly to pivot in two mutually perpendicular directions.

In another embodiment of the invention the pivot linkage is operable to pivot about a horizontal pivot axis and about a vertical pivot axis.

In a further embodiment of the invention a load sensor is provided on the hitch assembly for sensing the load applied to the hitch assembly by the attachment during use, and an actuator for the pivot linkage of the hitch assembly is operable in use in response to the sensed load to control the distribution of load between the tractor and the attachment.

In one embodiment of the invention the actuator is one or more rams operable to pivot the pivot linkage about one or both pivot axes.

In another embodiment of the invention a turntable is mounted on a hitch assembly part for rotating the connector assembly.

In a further embodiment of the invention the male element and the associated female element have a frusto-pyramidal shape.

In one embodiment of the invention retractable locking pins are mounted on mating side faces of one or both of the male and the female element, the locking pins being engagable with associated receiver sockets in the other of the male element and the female element.

In one embodiment of the invention the connector assembly includes an alignment device for the male element and the female element. Preferably, a laser alignment device is centrally mounted on the male element for alignment of the male and female elements upon engagement.

In another embodiment of the invention auxiliary services for operating the attachment are routed through the hitch assembly.

In another embodiment, the first part includes the pivot linkage.

In a further embodiment, the first part has an articulated body with an inner part pivotally mounted on the mounting plate by a first pivot pin and an outer part is pivotally mounted on the inner part by a second pivot pin for pivoting the outer part relative to the inner part, the pivot pins having mutually perpendicular pivot axes.

In another embodiment, the first pivot pin is for pivoting the inner part about a horizontal pivot axis and the second pivot pin is for pivoting the outer part relative to the inner part about a vertical pivot axis.

In another aspect the invention provides a tractor incorporating the tractor hitch assembly. Preferably the first part includes the pivot linkage and the turntable.

In one embodiment of the invention the tractor is mounted on a pair of track assemblies, each track assembly being pivotally mounted on the tractor.

In another embodiment of the invention the tractor is mounted on two longitudinally spaced-apart pairs of wheels, at least one pair of wheels being mounted for vertical movement on a chassis of the tractor.

In a further embodiment of the invention a 360° camera is mounted on the tractor and connects to an associated remote virtual reality controller to control operation of the tractor. In another embodiment, the camera is mounted within a transparent dome.

In another embodiment, a wiper is mounted on the dome which is operable to clean an outside face of the dome.

In one embodiment of the invention, a heater element is mounted within the dome.

In another embodiment of the invention the dome includes air jets to direct an air stream across the dome.

In one embodiment of the invention the tractor has an electrical power pack.

In another embodiment of the invention the electrical power pack is powered by an internal combustion engine.

In a further embodiment of the invention the electrical power pack connects through the hitch assembly with the attachment to drive the attachment. In a further embodiment of the invention the electrical power pack includes a batery which is connected to the engine for charging the battery with excess power generated by the engine.

Brief Description of the Drawings

The invention will be more clearly understood by the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings, in which: Fig, 1 is a perspective view of a tractor according to the invention;

Fig. 2 is a rear perspective view of the tractor;

Fig. 3 is a side elevational view of the tractor; Fig, 4 is a rear elevational view of the tractor;

Fig, 5 is a plan view of the tractor;

Fig, 6 is a detail side elevational view of the tractor and an associated tractor hitch assembly according to the invention;

Fig. 7 is a view similar to Fig. 6 showing the tractor hitch assembly in a disconnected position;

Fig. 8 is a perspective view of a female part of the hitch assembly;

Fig. 9 is an elevational view of the female part shown in Fig, 8;

Fig. 10 is a plan view of the female part shown in Fig. 8;

Fig, 11 is a rear perspective view of the tractor showing a male part of the hitch assembly mounted thereon;

Fig. 12 is an elevational view of the tractor and hitch assembly;

Fig. 13 is a perspective view showing a baler connected to the tractor by the hitch assembly;

Fig. 14 is an elevational view showing the baler connected to the tractor;

Fig. 15 is a perspective view showing a digger mounted on the hitch assembly of the tractor; and

Fig. 16 is a plan view showing the digger atachment mounted on the tractor.

Detailed Description of the Preferred Embodiments

Referring to the drawings, there is illustrated a tractor according to the invention indicated generally by the reference numeral 1 incorporating portion of a tractor hitch assembly according to another embodiment of the invention, indicated generally by the reference numeral 2. The hitch assembly 2 is for mounting an attachment such a baler 3 (Fig. 14) or a digger arm 4 (Fig. 15) on the tractor 1.

Referring in particular to Fig. 7, the hitch assembly 2 is of two part construction comprising a first part 5 for mounting on the tractor 1 and a second part 6 for mounting on the attachment 3, 4. Each part 5, 6 has means for mounting the part 5, 6 on the tractor 1, or on the attachment 3, 4 which in this case comprise a tractor mounting plate 7 and an attachment mounting plate 8 for bolting to the tractor 1 and to the attachment 3, 4 respectively,

A connector assembly 10 for interconnecting the two parts 5, 6 comprises a male element 11 and a complementary female element 12 for reception of the male element 11. Retractable locking pins 14 on the male element 11 are releasably engagable with associated receiver sockets 15 on the female element 12 to releasably rigidly lock the male element 11 in engagement with the female element 12.

Referring in particular to Fig. 11 and Fig. 12, the first part 5 of the hitch assembly 2 includes a pivot linkage to allow the connector assembly 10 to pivot in two mutually perpendicular directions. In this case the first part 5 has an articulated body with an inner part 16 pivotally mounted on the mounting plate 7 by a first pivot pin 18 for pivoting the inner part 16 about a horizontal pivot axis. That is to say the pivot axis is horizontal when the tractor 1 is standing on a horizontal surface. An outer part 20 is pivotally mounted on the inner part 16 by a second pivot pin 22 for pivoting the outer part 20 relative to the inner part 16 about a vertical pivot axis which is perpendicular to the horizontal pivot axis of the pivot pin 18, that is the pivot axis of the pivot pin 22 is vertical when the pivot pin 18 and inner part 16 are in a horizontal position. A turntable 24 is rotatably mounted at an outer end of the outer part 20 for rotating the male element 11 about a central longitudinal axis A of the first part 5.

The inner part 16 and the outer part 20 each have a box-section body. The mate element 11 at an outer end of the first part 5 of the hitch assembly 2 has a frusto- pyramidal shape with outwardly and inwardly sloping side faces 26 terminating in a flat rectangular end plate 27. The locking pins 14 retract into the male element 11 for engaging and disengaging with the female element 12 and move outwardly of each side face 26 to lock the male element 11 rigidly in engagement with the female element 12, A laser alignment device 29 is mounted within a central slot in the end plate 27 for cooperation with the female element 12 to correctly align the male element 11 and female element 12 for interengagement.

Referring in particular to Fig. 6 and Fig. 7 an accordion style flexible sleeve 30 is mounted on the first part 5 to protect the pivot linkage.

The second part 6 of the hitch assembly 2 also has a box section steel body 32 with the mounting plate 8 at the inner end for bolting to the attachment 3, 4 and the female element 12 of the connector assembly 10 at the free outer end.

Auxiliary services such as an electric power supply and pneumatic or hydraulic pipes for connection between the tractor 1 and the attachment 3, 4 are routed through the hitch assembly 2, Suitable connectors (not shown) are provided on the male element 11 and the female element 12 for connecting the auxiliary services from the tractor to the atachment 3, 4 upon engagement of the connector assembly 10.

Referring in particular to Fig. 11 and Fig. 12, the tractor 1 is an autonomous diesel/gas electric tractor and comprises a steel chassis 40 which in this case is mounted on a pair of track assemblies 41, 42. A diesel electric power plant 44 (Fig. 1) is mounted on the chassis 40 and is housed within a transparent canopy 45. A support frame 46 on the chassis 40 comprises upwardly extending side arms 47 at each side of the chassis 40 interconnected at their upper ends by a cross-beam 48. A GPS unit 50 is centrally mounted on the cross-beam 48 and is operable to control movement of the tractor 1.

A 360° camera 52 is also mounted on the cross-beam 48 on an underside of the cross-beam 48 and connects to an associated remote virtual reality controller 54 to control operation of the tractor 1 instead of using the GPS unit 50, if desired. The camera 52 is mounted within a transparent dome 53 for protection from dust and the elements. A wiper (not shown) is provided on the dome 53 which is operable to clean an outside face of the dome 53. Also, air-jets may be provided to direct an airstream across the dome 53 to keep dust away from the dome 53 in use. The dome 53 may include a heater element to cope with frosty conditions.

Each track assembly 41, 42 is pivotally mounted the chassis 40 by a pivot connector 56 for pivoting intermediate its ends in a vertical plane parallel to a longitudinal axis of the tractor 1. A ram 57 extends between the chassis 40 and a roller-carrying plate 58 of the track assembly 41, 42. The ram 57 is operable to raise and lower a front end of the track assembly 41, 42 as shown in Fig. 12. Thus, the tractor chassis 40 can be pivoted on the track assemblies 41, 42 for improved stability when moving up or down a slope in use.

Each track assembly 41, 42 is mounted between a drive wheel 59 which is rotatably mounted at a rear end of the roller-carrying plate 58 and a guide wheel 60 rotatably mounted at a front end of the roller-carrying plate 58. Intermediate rollers 61 rotatably mounted on the roller-carrying plate 58 support the track assemblies 41, 42 between the drive wheel 59 and guide wheel 60. Hydraulic drive motors 64 drive the drive wheels 59 and hence the track assemblies 41, 42.

It will be appreciated that while track assemblies 41 , 42 have been shown on the tractor 1 , in an alternative arrangement the tractor 1 could be mounted on spaced- apart pairs of wheels. In such a case, one or both of the pairs of wheels may be movable on the chassis 40 for tilting the chassis 40 on the wheels of the tractor 1 as previously described when negotiating slopes for improved stability.

A battery (not shown) is also mounted on the chassis 40. The power pack 44 is arranged such that the diesel engine can run at its most efficient speed. When maximum power is not being drawn by the atachment 3, 4 excess power is used to charge the battery. Thus it will be appreciated that the diesel engine is run at optimum efficiency at all times and any excess power not required is stored in the battery for later use to greatly improve the efficiency of the tractor 1.

A three-point linkage 70 or other connector such as the hitch assembly 2 may be mounted also at a front end of the chassis 40 for mounting attachments thereon when required.

In use, the tractor 1 may be controlled using the GPS unit 50, or the camera 52 and associated virtual reality control unit 54. Coupling the tractor 1 up to an attachment 3, 4 is relatively simple and quick by engaging the male element 11 with the associated female element 12 and locking the elements 11, 12 rigidly together by means of the locking pins 14. Upon coupling the connector assembly 10 auxiliary services for operating the attachment 3, 4 are automatically connected to the power supply from the tractor 1. The pivots 18, 22 and rotator 24 of the first part 5 of the hitch assembly 2 can be operated for manoeuvring the attachment 3, 4, A load sensor on the hitch assembly 2 senses the load applied to the hitch assembly 2 by the attachment 3, 4 during use. Rams associated with the pivots 18, 22 are operable to pivot the inner part 16 and outer part 20 for controlling the distribution of load between the tractor 1 and the attachment 3, 4.

In this specification the terms “comprise, comprises, comprised and comprising” or any variation thereof and the terms Include, includes, included and including" or any variation thereof are considered to be totally interchangeable and they should all be afforded the widest possible interpretation.

The invention is not limited to the embodiments hereinbefore described which may be varied in both construction and detail within the scope of the appended claims.

Claims

1. A tractor hitch assembly (2) for mounting an attachment (3, 4) on a tractor (1), the hitch assembly (2) being of two-part construction comprising a first part (5) for mounting on the tractor (1) and a second part (6) for mounting on the attachment (3, 4), each part (5, 8) having means (7, 8) for mounting the part (5, 6} on the tractor (1) or on the attachment (3, 4), and a connector assembly (10) comprising complementary releasably interengagable formations (11, 12) on the two parts (5, 6), the connector assembly (10) comprising a male element (11) and a complementary female element (12) for reception of the male element (11), and a lock (14, 15) to releasably rigidly lock the male element (11) in engagement with the female element (12) characterised in that the hitch assembly (2) includes a pivot linkage (16, 18, 20, 22) to allow the connector assembly (10) to pivot in two mutually perpendicular directions,

2, The tractor hitch assembly (2) as claimed in claim 1 wherein the pivot linkage (16, 18, 20, 22) is operable to pivot about a horizontal pivot axis and about a vertical pivot axis. 3, The tractor hitch assembly (2) as claimed in any one of the preceding claims, wherein a load sensor is provided on the hitch assembly (2) for sensing the load applied to the hitch assembly (2) by the attachment during use (3, 4), and an actuator for the pivot linkage (16, 18, 20, 22) of the hitch assembly (2) is operable in use in response to the sensed load to control the distribution of load between the tractor (1) and the attachment (3, 4).

4, The tractor hitch assembly (2) as claimed in claim 3 wherein the actuator is one or more rams operable to pivot the pivot linkage (16, 18, 20, 22) about one or both pivot axes,

5. The tractor hitch assembly (2) as claimed in any one of the preceding claims, wherein a turntable (24) is mounted on a hitch assembly part (5, 6) for rotating the connector assembly (10), 6, The tractor hitch assembly (2) as claimed in any one of the preceding claims, wherein the male element (11) and the associated female element (12) have a frusto-pyramidal shape.

7. The tractor hitch assembly (2) as claimed in any one of the preceding claims, wherein retractable locking pins (14) are mounted on mating side faces (28) of one or both of the male element (11) and the female element (12), the locking pins (14) being engagabte with associated receiver sockets (15) in the other of the male element (11) and the female element (12).

8. The tractor hitch assembly (2) as claimed in any one of the preceding claims, wherein a laser alignment device (29) is centrally mounted on the male element (11) for alignment of the male element (11) and female element (12) upon engagement.

9. The tractor hitch assembly (2) as claimed in any one of the preceding claims, wherein auxiliary services for operating the attachment (3, 4) are routed through the hitch assembly (2).

10. The tractor hitch assembly (2) as claimed in any one of the preceding claims, wherein the first part (5) includes the pivot linkage (18, 18, 20, 22).

11. The tractor hitch assembly (2) as claimed in claim 10, wherein the first part (5) has an articulated body with art inner part (16) pivotally mounted on the mounting plate (7) by a first pivot pin (18) and an outer part (20) is pivotally mounted on the inner part (16) by a second pivot pin (22) for pivoting the outer part (20) relative to the inner part (16), the pivot pins (18, 22) having mutually perpendicular pivot axes.

12. The tractor hitch assembly (2) as claimed in claim 11 , wherein the first pivot pin (18) is for pivoting the inner part (16) about a horizontal pivot axis and the second pivot pin (22) is for pivoting the outer part (20) relative to the inner part (16) about a vertical pivot axis.

13. A tractor (1) incorporating the tractor hitch assembly (2) as claimed in any preceding claim.

14. The tractor (1) as claimed in claim 13, wherein the first part (5) includes the pivot linkage (16, 18, 20, 22) and the turntable (24).

15. The tractor (1) as claimed in claim 13 or claim 14, wherein the tractor (1) is mounted on a pair of track assemblies (41, 42), each track assembly (41, 42) being pivotally mounted on the tractor (1).

16. The tractor (1) as claimed in claim 13 or claim 14, wherein the tractor (1) is mounted on two longitudinally spaced-apart pairs of wheels, at least one pair of wheels being mounted for vertical movement on a chassis (40) of the tractor (1).

17. The tractor (1) as claimed in any one of claims 13 to 16, wherein a 360° camera

(52) is mounted on the tractor (1) and connects to an associated remote virtual reality controller (54) to control operation of the tractor (1).

18. The tractor (1) as claimed in claim 17, wherein the camera (52) is mounted within a transparent dome (53).

19. The tractor (1) as claimed in claim 18, wherein a wiper is mounted on the dome

(53) which is operable to dean an outside face of the dome (53).

20. The tractor (1) as claimed in claim 18 or claim 19, wherein a heater element is mounted within the dome (53).

21. The tractor (1) as claimed in any one of claims 18 to 20 wherein the dome (53) indudes air jets to direct an air stream across the dome (53).

22. The tractor (1) as claimed in any one of claims 13 to 21 wherein the tractor (1) has an electrical power pack.

23. The tractor (1) as claimed in claim 22 wherein the electrical power pack is powered by an internal combustion engine.

24. The tractor (1) as claimed in claim 22 or claim 23 wherein the electrical power pack connects through the hitch assembly (2) with the attachment (3, 4) to drive the attachment (3, 4),

25. The tractor (1) as claimed in any one of claims 22 to 24 wherein the electrical power pack includes a batery which is connected to the engine for charging the battery with excess power generated by the engine.