US3653450A

US3653450A - Tilt compensation linkage for tilting bulldozer moldboard

Info

Publication number: US3653450A
Application number: US41899A
Authority: US
Inventors: Harvey W Rockwell; Wesley A Poore
Original assignee: Allis Chalmers Corp
Current assignee: Fiat Allis Europe SpA; Allis Chalmers Corp
Priority date: 1970-06-01
Filing date: 1970-06-01
Publication date: 1972-04-04
Anticipated expiration: 1989-04-04
Also published as: CA922892A

Abstract

Compensating linkage for a tilting bulldozer moldboard including a link depending from the rear of the moldboard with its lower end pivotally connected, at longitudinally spaced points, to the two dozer push arms.

Description

United States Patent Rockwell et al.

[451 Apr. 4, 1972 [54] TILT COMPENSATION LINKAGE FOR TILTING BULLDOZER MOLDBOARD [72] Inventors: Harvey W. Rockwell; Wesley A. Poore,

both of Springfield, Ill.

[73] Assignee: Allis-Chalmers Manufacturing Company,

Milwaukee, Wis.

[22] Filed: June 1, 1970 [21] Appl. No.: 41,899

[52] U.S. Cl ..l72/803, 172/806 [51] Int. Cl. ..E02f 3/76 [58] Field of Search ..172/803, 804, 801 807, 806

[56] References Cited UNITED STATES PATENTS 3,395,764 8/1968 Wirt ..l72/803 3,503,457 3/1970 Smith et al 172/803 3,049,820 8/1962 Lichti 1 72/803 3,025,620 3/1962 Liess 172/803 FOREIGN PATENTS OR APPLlCATlONS 1,136,998 12/1968 Great Britain 172/803 Primary Examiner-Robert E. Pulfrey Assistant Examiner-Stephen C. Pellegrino Attorney-Charles L. Schwab, Robert B. Benson and Kenneth C. McKivett [5 7] ABSTRACT Compensating linkage for a tilting bulldozer moldboard including a link depending from the rear of the moldboard with its lower end pivotally connected, at longitudinally spaced points, to the two dozer push arms.

7 Claims, 4 Drawing Figures Patnted April 4, 1972 3,653,450

2 Sheets-Sheet l Patented April 4, 1972 2 Sheets-Sheet 2 i www wwgz M m 2 m um WWW TILT COMPENSATION LINKAGE FOR TILTING BULLDOZER MOLDBOARD This invention relates to an improved compensating mechanism for a tilt dozer and particularly to the provision of a link depending from the rear of the blade and forming a longitudinal link between the diagonal brace structures of the push arms.

I'leretofore others have proposed compensating mechanisms for tilt dozers, such as shown in U.S. Pat. Nos. 3,049,820, 3,049,821 and 3,395,764. Such designs have not proven entirely satisfactory from the standpoint of cost, function and service.

It is an object of the present invention to provide an improved dozer tilt compensating mechanism which is simple in design, is low in cost and gives long trouble-free service.

It is a further object of this invention to provide a dozer tilt compensating mechanism wherein the diagonal brace structures of the push arms are interconnected by a longitudinally disposed link.

It is a further object of this invention to provide a dozer tilt compensation linkage of the type described in the previous object wherein the longitudinally disposed link depends from a pivot connection with the rear of the moldboard.

Theseand other objects and advantages of the present invention will be apparent when the following description is read in conjunction with the drawings, in which:

FIG. 1 is a partial side view of a tractor with a tilt dozer in which the present invention is incorporated;

FIG. 2 is a top view of the tractor and dozer of FIG. 1;

FIG. 3 is a section view taken on the line III-III in FIG. 2; and

FIG. 4 is a section view taken on the line IVIV in FIG. 3.

Referring to FIGS. 1 and 2, the push arms 11, 12 of the bulldozer 13 are connected on a transverse axis 14 to the track frames of a crawler tractor 16 by ball and socket joints l7, 18. The front end of the push arms are connected to transversely spaced points of the lower rear of the dozer moldboard 21 by spherical pivot connections 22, 23. Tilting of the moldboard is controlled by an extensible and contractible tilt brace in the form of a double-acting hydraulic jack 26, the rod 27 of which is pivotally connected to the upper rear of the moldboard by ball and socket connection 28 and the cylinder 29 of which is pivotally connected to push arm 11 and pin 31. At the opposite lateral side of the dozer 13, an upwardly extending tilt brace 32 has its opposite ends pivotally connected to the push arm 12 and upper rear of the moldboard 21.

The dozer is raised and lowered, about transverse axis 14, by contraction and expansion of a pair of double-acting jacks 33, 34 having their rods 36, 37 pivotally connected to brackets at the rear of the moldboard 21 and their

cylinders

38, 39

pivotally connected to the tractor 16. As customary, the hydraulic control for the jacks 33, 34 includes means (not shown) for hydraulically interconnecting corresponding ends of the

cylinders

38, 39.

The push arms include diagonal brace structures in the form of inwardly extending legs 41, 42. In order to interconnect the inner ends of these legs 41, 42 to provide lateral rigidity to the dozer and still allow relative longitudinal movement between the moldboard and the free ends of legs 41, 42, there is provided a longitudinal link 46 pivotally connected at longitudinally spaced points to the ends of legs 41, 42. The details of the link 46 and its connections to the legs 41, 42 and moldboard 21 are shown in FIGS. 3 and 4. The legs 41, 42 of the push arms are universally connected to the link 46 by universal pivots in the form of

spherical bearing assemblies

47, 48 which are' identical in construction and lie in the longitudinal vertical plane of the dozer and tractor. As shown in FIG. 4, bearing assembly 48 includes a pin 49 on which a spherical bearing 51 is held by a cap 52 and a bushing 53 with spherical socket which is held in place in bore 54 of link 46 by a pair of snap rings 56, 57. The upper end of the longitudinal link 46 is universally connected to

brackets

58, 59 of the moldboard 21, for longitudinal fore and aft swinging movement, by a spherical bearing assembly 61 including engaging spherically surfaced bearing

parts

62, 63. The center of the upper pivot connection of assembly 61 is spaced a distance 2 vertically above a line f passing through the centers of lower universal pivot connections of

assemblies

47, 48 which is slightly greater than twice the distance g between the centers of the

universal pivot assemblies

47 and 48. This properly allows the longitudinal movement of link 46 without adversely affecting the vertical position of the free ends of legs 41, 42.

OPERATION When the tilt brace jack 26 is expanded, the lateral end of the moldboard 21 to which the jack is connected will rise relative to its other lateral end. This will cause the free ends of legs 41, 42 to move closer to the rear of the moldboard. Depending link 46 permits this while still providing a connection between the push arms ll, 12 to provide lateral stability for the mold board. By pivotally connecting the link 46 to the rear of the moldboard the free ends of the legs 41, 42 are supported in the desired vertical position so they perform the desired diagonal bracing function. If the tilt jack 26 is contracted the adjacent moldboard end will be lowered and once again the ends of legs 41, 42 will move closer to the moldboard 21. Thus the depending and longitudinally extending link 46 and the longitudinally spaced

pivot connections

47, 48 with the push arms 1 l, 12 serve to compensate for dimensional changes occurring during tilting of the dozer.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In combination with a dozer having. a pair of longitudinally extending and laterally spaced push arms pivotally connected at their front ends to the rear of a moldboard and a pair of tilt braces extending upwardly between the top of the push arms and the blade, at least one of the tilt braces being extensible, a tilt compensating arrangement comprising:

a pair of diagonal brace structures extending laterally inwardly from said push arms toward one another with their inner ends terminating in longitudinally spaced relation to one another adjacent the rear of said moldboard,

a longitudinally extending link pivotally connected at longitudinally spaced points to said inner ends, respectively, of said brace structures, and

means pivotally connecting said link to the rear of said moldboard at a point spaced vertically from said longitudinally spaced points permitting longitudinal fore and aft swinging movement of said link, the distance between said point of pivot of said link to said moldboard and a line between the points of pivot between said link and structures is greater than the distance between said points of pivot between said link and structures.

2. The invention of claim 1 wherein said pivot connections between said link and said structures are universal pivot connections.

3. The invention of claim 2 wherein said pivot connection between said link and said moldboard is a universal pivot connection.

4. The structure of claim 3 wherein said universal connections are spherical bearing connections.

5. The structure of claim 1 wherein said diagonal brace structures are rigidly connected to said push arms.

6. In combination with a dozer having a pair of longitudinally extending and laterally spaced push arms pivotally connected at their front ends to the rear of a moldboard and a pair of tilt braces extending upwardly between the top of the push arms and the blade, at least one of the tilt braces being extensible, a tilt compensating arrangement comprising:

a pair of diagonal brace structures rigidly secured to and extending laterally inwardly from said push arms toward one another with their inner ends terminating in longitudinally spaced relation to one another adjacent the rear of said moldboard,

dinally spaced points. 7. The invention of claim 6 wherein said longitudinally spaced points lie substantially in the longitudinal vertical plane ofsaid dozer.

Claims

1. In combination with a dozer having a pair of longitudinally extending and laterally spaced push arms pivotally connected at their front ends to the rear of a moldboard and a pair of tilt braces extending upwardly between the top of the push arms and the blade, at least one of the tilt braces being extensible, a tilt compensating arrangement comprising: a pair of diagonal brace structures extending laterally inwardly from said push arms toward one another with their inner ends terminating in longitudinally spaced relation to one another adjacent the rear of said moldboard, a longitudinally extending link pivotally connected at longitudinally spaced points to said inner ends, respectively, of said brace structures, and means pivotally connecting said link to the rear of said moldboard at a point spaced vertically from said longitudinally spaced points permitting longitudinal fore and aft swinging movement of said link, the distance between said point of pivot of said link to said moldboard and a line between the points of pivot between said link and structures is greater than the distance between said points of pivot between said link and structures.

6. In combination with a dozer having a pair of longitudinally extending and laterally spaced push arms pivotally connected at their front ends to the rear of a moldboard and a pair of tilt braces extending upwardly between the top of the push arms and the blade, at least one of the tilt braces being extensible, a tilt compensating arrangement comprising: a pair of diagonal brace structures rigidly secured to and extending laterally inwardly from said push arms toward one another with their inner ends terminating in longitudinally spaced relation to one another adjacent the rear of said moldboard, a longitudinally extending link pivotally connected at longitudinally spaced points to said inner ends, respectively, of said brace structures for universal movement relative thereto, and means universally connecting said link to the rear of said moldboard at a point spaced vertically from said longitudinally spaced points.

7. The invention of claim 6 wherein said longitudinally spaced points lie substantially in the longitudinal vertical plane of said dozer.