GB2120062A

GB2120062A - Yieldable plough body mounting

Info

Publication number: GB2120062A
Application number: GB08214489A
Authority: GB
Inventors: Charles Vernon Roge Dowdeswell
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-05-18
Filing date: 1982-05-18
Publication date: 1983-11-30
Also published as: GB2120062B

Abstract

Maximum initial spring loading is effected against initial upward yielding movement of an arm (1) carrying a plough body (11) on encountering an obstruction in the ground. This is achieved by lever action linkage (5) consisting of a bell crank (50) pivotally mounted by a bracket (15) from the rear of the arm (1) and pivotally connected to the rear end of a connecting rod (40) which extends along the arm (1) from anchorage (42) to the support structure (2,3). The bell crank lever (50) is also pivotally connected by a further lever (55) to a return spring (44), the lever being intermediately supported from the bracket (15) by a link (53) or roller for angular movement and also for generally endwise movement. On initial upward yielding movement of the arm (1) angular movement is imparted to the lever (55) for initial rapid extension of the spring (44). Thereafter further generally endwise movement of the lever (55) results in little or no further spring loading against the arm (1) on continued upward movement of the latter. <IMAGE>

Description

SPECIFICATION Yieldable plough body mounting This invention relates to the yieldable mounting of a plough body for minimising damage to the body or ploughshare and plough structure generally in the event ofthe body or share striking a stone, rock, root or similar obstruction in the ground,the mounting having an automatic return or resetaction backtothe normal ploughing position afterthe obstruction has been passed. The invention has particular, but not exclusive, practical application to multi-body reversible ploughs.

The invention is concerned with such yieldable mounting ofthe kind in which a plough body in a lowermost position of use is carried by a depending rear part or leg of an arm,which arm is pivotally connected by a connecting rod or similar elongate means or assembly to support means mounted or mountable on plough structure such as a beam of the latter, the forward end of the arm also having pivotal contact with the support means at one or more points or locations adjacent or about the pivotal connection whereby pivotal angular movement ofthe arm is able to take place for yielding movement of the arm in an upward direction against the action of resiliently acting return means acting between the arm and connecting rod.

The object of the invention is to provide a yieldable mounting in which optimum use is made to the spring loading in obtaining a suitable yielding action and at the same time provide a simple and effective construction.

According to the invention yieldable plough body mounting ofthe kind referred to is characterised by return spring means (or other resiliently acting return means) connected to the arm being connected to the rear of the connecting rod or similar elongate means or assembly by lever action linkage mounted on or from the arm whereby relative movement ofthe arm and connecting rod or initial upward yielding movement ofthe arm causes rapid extension of the return spring means or the likefor providing maximum spring loading againstthe initial yielding movement of the arm and thereafter substatially reduced or virtually no further extension ofthe return spring means orthe like on further upward yielding move mentofthe arm.

Practical examples ofthe yieldable plough body mounting are shown in the accompanying drawings in which: FIGURE lisa plan view, FIGURE 2 is a detail plan view on an enlarged scale ofthe linkage.

FIGURE 3 is a detail viewsimilarto FIGURE2 but showing an alternative form of linkage, and FIGURE 4 is a detail side elevation of adjustable connecting rod anchorage.

A rearwardly extending or trailing arm 1 having a hollow interior and which is substantially horizontal in the operative position is pivotally connected to support means 2from the beam 3 of the plough structure which beam 3 is rearwardly inclined in the usual manner, i.e. in generally horizontal plane in position of use.

In the case of a reversible plough the rear of the arm carries a pair of oppositely directed legs (not shown) the lower depending one of which carries a plough body 11 in the operative position.

The support means 2 is shown consisting of a member or plate 20 mounted by a bracket 23 from the plough beam 3 so as to extend laterally from the latter and to which bracket 23 the arm 1 is pivotally connected or anchored at 42, i.e. by an elongate member or rod 40. The rod 40 is co-axial with the pivotal connection 42 and passes along the interior of the tubular arm 1 and extends at its rear end from the latter.

The forward end of the arm 1 has pivotal contact points at 21 with the support 20 for rocking movement in permitting upward yielding movement of the arm 1 on the plough body 11 encounter- an obstruction.

Connected between a bracket 14attheforward end of the arm 1 and leveraction linkage 5 carried buy a further bracket 15 from the rear of the arm 1 is resiliently acting return means shown in the form of a tension spring 44 the rear end of which is pivotally connected bythe linkage 5tothe rear end ofthe connecting rod 40.

The arrangement ofthe linkage 5 and its pivotal mounting from the bracket 15 is such that on initial upward yielding movementofthearm 1 tending to take place with corresponding relative movement of the arm 1 and connecting rod 40, a considerably greater or magnified extent of extension of the spring 44takes place so that maximum spring loading is provided against such initial yielding movement. This ensures that the plough body 11 is retained in the ground under normal ploughing conditions so that yielding onlytakes place on the plough body 11 encountering an obstruction in the ground.On upward yielding movement of the arm 1 taking place and bearing in mindtheforward pivotal anchorage 42 of the connecting rod 40, rearward longitudinal movement ofthe rear ofthe arm 1 takes place relative to the rear of the connecting rod 1. This causes the connecting rod 40to impart anti-clockwise angular movement to a bell crank lever 50 ofthe linkage 5 and shown in the form of a triangular plate which is pivotally mounted at 51 from the rear bracket 15 whereby the lever is caused to swing laterally inwardly towards the arm 1.

However on such initial pivotal movement of the bell crank lever 50 it causes a further lever 55 pivotally connected between the lever 50 and the rear end of the spring 44 to rock about intermediate pivotal mounting 52 ofthe lever55fromthe rear bracket 15 bya link53.

This initial anti-clockwise pivotal movement of the lever 55 causes somewhat greater extension movement of the spring 44 in relation to the relative movement ofthe connecting rod 40 and arm 1 so that maximum spring loading is imparted to the arm 1 against its initial upward yielding movement.

The drawing(s) originally filed was/were informal and the print here reproduced is taken from a later filed formal copy.

However as yielding movement ofthe arm 1 continues with further relative rearward longitudinal movement of the arm 1 in relation to the connecting rod 40, the inward swinging movement of the bell crank lever 50 pulls the lever 55 downwardly about its pivotal connection 54 by the link 53 to the rear bracket 15, i.e. to the position shown in dotted lines. Such generally endwise movement ofthe lever 55 results in little or no further extension ofthe spring 44 so that furtherupwardyielding movementofthearm 1 is able to take place with a minimum ofsuchfurther extension ofthe spring 44, i.e. in a virtually free manner.

The arrangement also has the advantage that the spring 44 requires to have little pre-loading in the normal position of the arm 1 but as soon as upward yielding movement commences comparatively rapid initial extension of the spring 44takes place to provide maximum spring loading on the arm 1 and rod 40 againsttheintialyielding movementofthearm 1.

However as immediately thereafter little or no further extension ofthe spring takes place on furtheryielding movement ofthe arm 1 ,the spring 44 is not damaged or ruptured by over-stressing, i.e. in the case of a powerful spring having a limited degree of extension.

In FIGURE 3 a modified arrangement of the linkage 5 is shown in which the link 53 is replaced by a roller 56 rotatably mounted at an intermediate point on the lever 55 and cooperating with the profile 160 of a cam member or plate 16 fixedly mounted on the rear end part ofthe arm 1. The co-action ofthe roller 56 with the cam profile 160 is such thatthe lever 55 in conjunction with the bell crank lever 50 has a similar action to that already described in obtaining rapid initial extension ofthe spring 44followed by little or no further extensionofthespringasupwardyielding movement ofthearm 1 continues. The bell crank leveris shown pivotally mounted at 51 on the plate 16 in a similar mannerto its pivotal mounting on the bracket 15 in FIGURE 2.

It is to be understoodthatthe leverage provided by the linkage 5 may be varied according to requirements by appropriate relative effective lengths of the levers 50,55 and any link 53 and their pivotal connection and mounting. The form of the cam profile 160 may be also varied.

In orderto setthe assembly so as to have the required operating characteristics the pivotal anchorage 42 ofthe connecting rod 40 to the bracket 23 may be adjustable forwardly or rearwardly. Thus, as shown in FIGURE4, the connecting rod 40 is pivitally connected at42 to a shackle bolt 24 passing through a forward part 230 of the bracket 23 and receiving a nut 25. The pivotal connection 42 is also shown guided at 22fromthebracket23forsuch adjustment.

In setting the assembly in this way appropriate clearance is observed between the adjacent side ofthe rear ofthe connecting rod 40 and the pivotal connection 51 ofthe bell crank lever 50 to the rear bracket 15 (FIGURE 2) or cam plate 16 (FIGURE 3).

As also shown in FIGURE 4the connecting rod 40 may be pivotallyjoined at 45to permit a greater extent of upward yielding movement of the arm 1 as necessary.

In a further alternative arrangement the lever 55 and any link 53 may be omitted and the bell cranklever50 formed or provided with outward extension which is directly pivotally connectedto the rear end ofthe spring 44. To some extentthiswould provide a similar but less accommodating action especially as regards reduction of spring extension on further upward yielding movement ofthe arm 1.

CLAIMS (Filed on 16/5/83) 1. Yieldable plough body mounting ofthe kind referred to characterised by return spring means (or other resiliently acting return means) connected to the arm being connected to the rear ofthe connecting rod orsimilar elongate means or assembly by lever action linkage mounted on orfrom the rear ofthe arm whereby relative movement ofthe arm and connecting rod on initial upward yielding movementofthe arm causes rapid extension of the return spring means orthe like for providing maximum spring loading againstthe initial yielding movement ofthe arm and thereafter little or virtually no further extension of the return spring means orthe like on further upward yielding movement of the arm.

2. Yieldable plough body mounting according to claim 1 wherein the lever action linkage comprises a bell crank or similar lever pivotally mounted on or from the rear end ofthe arm and pivotally connected to the rear end of the connecting rod or similar elongate means or assembly, the bell crank or similar lever being also pivotally connected to one end of a further lever intermediately supported for angular movement and also for generally endwise movement from the arm and pivotally connected at its other end to the return spring means orthe like whereby on relative longitudinal movement ofthe arm and connecting rod orthe liketaking place on initial upward yielding movement ofthearm, turning movement is imparted to the bell crank or similar lever about its pivotal mounting on orfrom the arm which in turn imparts initial angular movement to the further lever for effecting initial rapid extension ofthe return spring means orthe likeforsaid maximum spring loading againstthearm and which isfollowed by further generally endwise movement ofthe further lever resulting in little orvirtually no further extension ofthe return spring means orthe like on continued upward yielding movement of the arm.

3. Yieldable plough body mounting according to claim 2 wherein the further lever is intermediately supported for angular and generally endwise movement from the arm by a link pivotally connected to an intermediate part ofthe further lever and pivotally connected to the arm.

4. Yieldable plough body mounting according to claim 2 wherein the further lever is intermediately supported for angular and generally endwise move mentfrom the arm by cam co-action with a part carried bythe latter.

5. Yieldable plough body mounting according to claim 4wherein a roller rotatably carried by an intermediate part ofthe further lever co-acts with cam formation of a member carried by the arm.

6. Yieldable plough body mounting according to any of claims 2 to 5wherein a bracket mounted on the rear end ofthe arm pivotally carriesthe bell crank or similar lever and also provides intermediate support

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. However as yielding movement ofthe arm 1 continues with further relative rearward longitudinal movement of the arm 1 in relation to the connecting rod 40, the inward swinging movement of the bell crank lever 50 pulls the lever 55 downwardly about its pivotal connection 54 by the link 53 to the rear bracket 15, i.e. to the position shown in dotted lines. Such generally endwise movement ofthe lever 55 results in little or no further extension ofthe spring 44 so that furtherupwardyielding movementofthearm 1 is able to take place with a minimum ofsuchfurther extension ofthe spring 44, i.e. in a virtually free manner. The arrangement also has the advantage that the spring 44 requires to have little pre-loading in the normal position of the arm 1 but as soon as upward yielding movement commences comparatively rapid initial extension of the spring 44takes place to provide maximum spring loading on the arm 1 and rod 40 againsttheintialyielding movementofthearm 1. However as immediately thereafter little or no further extension ofthe spring takes place on furtheryielding movement ofthe arm 1 ,the spring 44 is not damaged or ruptured by over-stressing, i.e. in the case of a powerful spring having a limited degree of extension. In FIGURE 3 a modified arrangement of the linkage 5 is shown in which the link 53 is replaced by a roller 56 rotatably mounted at an intermediate point on the lever 55 and cooperating with the profile 160 of a cam member or plate 16 fixedly mounted on the rear end part ofthe arm 1. The co-action ofthe roller 56 with the cam profile 160 is such thatthe lever 55 in conjunction with the bell crank lever 50 has a similar action to that already described in obtaining rapid initial extension ofthe spring 44followed by little or no further extensionofthespringasupwardyielding movement ofthearm 1 continues. The bell crank leveris shown pivotally mounted at 51 on the plate 16 in a similar mannerto its pivotal mounting on the bracket 15 in FIGURE 2. It is to be understoodthatthe leverage provided by the linkage 5 may be varied according to requirements by appropriate relative effective lengths of the levers 50,55 and any link 53 and their pivotal connection and mounting. The form of the cam profile 160 may be also varied. In orderto setthe assembly so as to have the required operating characteristics the pivotal anchorage 42 ofthe connecting rod 40 to the bracket 23 may be adjustable forwardly or rearwardly. Thus, as shown in FIGURE4, the connecting rod 40 is pivitally connected at42 to a shackle bolt 24 passing through a forward part 230 of the bracket 23 and receiving a nut 25. The pivotal connection 42 is also shown guided at 22fromthebracket23forsuch adjustment. In setting the assembly in this way appropriate clearance is observed between the adjacent side ofthe rear ofthe connecting rod 40 and the pivotal connection 51 ofthe bell crank lever 50 to the rear bracket 15 (FIGURE 2) or cam plate 16 (FIGURE 3). As also shown in FIGURE 4the connecting rod 40 may be pivotallyjoined at 45to permit a greater extent of upward yielding movement of the arm 1 as necessary. In a further alternative arrangement the lever 55 and any link 53 may be omitted and the bell cranklever50 formed or provided with outward extension which is directly pivotally connectedto the rear end ofthe spring 44. To some extentthiswould provide a similar but less accommodating action especially as regards reduction of spring extension on further upward yielding movement ofthe arm 1. CLAIMS (Filed on 16/5/83)

1. Yieldable plough body mounting ofthe kind referred to characterised by return spring means (or other resiliently acting return means) connected to the arm being connected to the rear ofthe connecting rod orsimilar elongate means or assembly by lever action linkage mounted on orfrom the rear ofthe arm whereby relative movement ofthe arm and connecting rod on initial upward yielding movementofthe arm causes rapid extension of the return spring means orthe like for providing maximum spring loading againstthe initial yielding movement ofthe arm and thereafter little or virtually no further extension of the return spring means orthe like on further upward yielding movement of the arm.

forthefurtherieverforangular movement and generally endwise movement ofthe latter.

7. Yieldable plough body mounting according to claim 1 wherein the lever action linkage comprises a bell crank orsimilar lever pivotally mounted on or from the rear end ofthe arm and pivotally connected to the rear end of the connecting rod or the like, which lever is formed or provided with an extension member pivotally connected to the rear end ofthe return spring means orthe like on relative longitudinal movement ofthe arm and connecting rod orthe like on initial upward yielding movement of the arm, turning movement in impacted to the bell crank or similar lever causing angular movement ofthe extension memberthereof for initially effecting rapid extension of the return spring means or the like followed by further angular and endwise movement of the extension memberwhich results in a substantially reduced rateoffurtherextensionofthereturnspring means or the like on continued upward yielding movement of the arm.

8. Yieldable plough body mounting according to anyofthe preceding claims wherein pivotal anchorage ofthe connecting rod or similar elongate means or assembly to the support means mounted or mountable on plough structure is adjustable forwardly or rearwardlyfor obtaining required operating characteristics ofthe connecting rod or the like and the arm and ofthe lever action linkage.

9. Yieldable plough body mounting according to claim 8wherein the pivotal anchorage of the connecting rod orthe liketo the support means is effected by a shackle bolt of similar member arranged for longitudinal screw adjustment relative to the support means.

10. Yieldable plough body mounting ofthe kind referred to substantially as herein described with reference to FIGURES 1 and 2 or FIGURE 3 or FIGURE a oftheaccompanying drawings.