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Publication numberUS3786953 A
Publication typeGrant
Publication dateJan 22, 1974
Filing dateNov 16, 1972
Priority dateNov 16, 1972
Also published asCA993836A1, DE2357365A1, DE2357365B2, DE2357365C3
Publication numberUS 3786953 A, US 3786953A, US-A-3786953, US3786953 A, US3786953A
InventorsCrum R, Patel I
Original AssigneeAllis Chalmers
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Loader linkage
US 3786953 A
Abstract
The bucket control linkage of a tractor loader includes a vertically disposed lever pivotally connected intermediate its upper and lower ends to a boom. A dump link is interconnected between the lower end of the lever and the upper rear of the bucket. The bucket control linkage also includes a bucket operating jack having its front rod end pivotally connected to the upper end of the lever and its rear cylinder end pivotally connected to a special linkage. The special linkage includes a pair of pivotally interconnected links, one of which is pivotally connected to the boom and the other of which is pivotally connected to the tractor frame at a point spaced forwardly of the pivot connection between the boom and the frame. The special linkage to which the cylinder end of the bucket operating jack is connected, causes the bucket to automatically retract as the boom is raised through an initial angle toward its level position and then will cause the bucket to pivot forwardly relative to the boom to maintain the bucket in a proper material retaining altitude in relation to the ground. The various components of the bucket operating linkage are in line with the longitudinal vertical plane of the boom for ideal component stress distribution. The bucket is retracted by introduction of hydraulic fluid to the cylinder end of the dumping jack whereby the greatest possible breakout force is achieved by the jack. The rod end of the hydraulic jack is pressurized to dump the bucket thus giving the shortest possible dumping time. The connections between the bucket operating linkage and the frame of the tractor are relatively low thereby affording good operator visibility and desirable loader frame stress distribution.
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Description  (OCR text may contain errors)

United States Patent [191 Crum et al.

[451 Jan. 22, 1974 LOADER LINKAGE [75] Inventors: Robert L. Crum; Ishwarlal P. Patel,

both of Springfield, Ill.

[73] Assignee: Allis-Chalmers Corporation,

Milwaukee, Wis.

[22] Filed: Nov. 16, 1972 [21] Appl. No.: 307,054

[52] US. Cl. 214/776, 214/778 [51] Int. Cl E02f 3/00 [58] Field of Search 214/776, 775, 773, 769

[56] References Cited UNITED STATES PATENTS 9/1969 Campbell 214/776 10/1965 Mclndoo 214/776 Primary Examiner-Gerald M. Forlenza Assistant Examiner-John Mannix Attorney, Agent, or Firm-Charles L. Schwab; Robert B. Benson; Kenneth C. McKivett 5 7 ABSTRACT control linkage also includes a bucket operating jack having its front rod end pivotally connected to the upper end of the lever and its rear cylinder end pivotally connected to a special linkage. The special linkage includes a pair of pivotally interconnected links, one of which is pivotally connected to the boom and the other of which is pivotally connected to the tractor frame at a point spaced forwardly of the pivot connection between the boom and the frame. The special linkage to which the cylinder end of the bucket operating jack is connected, causes the bucket to automatically retract as the boom is raised through an initial angle toward its level position and then will cause the bucket to pivot forwardly relative to the boom to maintain the bucket in a proper material retaining altitude in relation to the ground. The various components of the bucket operating linkage are in line with the longitudinal vertical plane of the boom for ideal component stress distribution. The bucket is retracted by introduction of hydraulic fluid to the cylinder end of the dumping jack whereby the greatest possible breakout force is achieved by the jack. The rod end of the hydraulic jack is pressurized to dump the bucket thus giving the shortest possible dumping time. The connections between the bucket operating linkage and the frame of the tractor are relatively low thereby affording good operator visibility and desirable loader frame stress distribution.

10 Claims, 3 Drawing Figures PATENTED JAN 22 I974 SHEET 10F 2 PATENTEB JAN 2 21974 SHEET20F2 LOADER LINKAGE BACKGROUND OF THE INVENTION l-leretofore others have suggested various linkages for tractor loaders. There are a number of prior art linkages shown in US. Pat. Nos. 2,846,097; 2,645,369; 3,057,496; 2,799,412; 3,389,820; 2,986,l66; 3,598,267; 3,224,607; 2,711,257 and Re 24,746.

BRIEF DESCRIPTION OF THE INVENTION The present invention provides a loader linkage which achieves a number of desirable objectives, these being:

1. The bucket dumping cylinders are positioned so that the closed end of the cylinder is pressurized to retract the bucket thereby providing the greatest possible breakout force for loading the bucket, and the rod end of the cylinder is pressurized to dump the bucket thereby providing the fastest possible dumping;

2. A unique linkage is utilized to mount the cylinder end of the dump jack whereby the bucket will automatically pivot on the boom to maintain a relatively level position so that the operator does not have to operate the bucket control valve as the boom is raised. Also, a dirt bank can be scraped by the bucket with greater ease and the center of gravity of the bucket load with the bucket fully retracted is relatively close to the tractor thereby aiding in unit stability;

3. The bucket tilt linkage consists of in line components thereby providing the most desirable component stress distribution; and

4. The linkage by which the bucket operating jack is connected to the frame is relatively low thereby providing good operator visibility and minimizing tractor frame stress problems.

BRIEF DESCRIPTION OF THE DRAWINGS One embodiment of the present invention is illustrated in the attached two sheets of patent drawings in which:

FIG. 1 is a side view of a tractor loader incorporating the present invention;

FIG. 2 is a top view of the loader linkage shown in FIG. 1 with parts broken away for illustration purposes and FIG. 3 is a side view of the tractor loader shown in FIG. 1 wherein the loader linkage has been raised to an elevated position.

DETAILED DESCRIPTION OF THE INVENTION Referring to FIGS. 1 and 2 of the drawings, the loader linkage of the present invention is mounted on a crawler tractor 11 having a frame 12 which includes an upstanding support 13 at each lateral side of the tractor. The tractor 11 is supported on and propelled by an endless track running gear 14 of conventional construction. The loader linkage includes a boom 16 pivotally mounted at its rear end to the support 13 of the tractor frame 12 by a transverse pivot pin 17 on a transverse axis 18. A bucket 19 is pivotally connected at its lower rear portion to the front end of the boom 16 by a pivot pin 21 on a transverse axis 22. Raising and lowering of the boom is achieved by operation of a double acting hydraulic jack 23 having its rod end pivotally connected to a downwardly depending part 24 of the boom 16 by a transverse pivot pin 26. The cylinder 27 of the jack 23 is secured to the frame 12 by a trunnion 28 on a transverse pivot axis 19. A lever structure 31 is connected intermediate its opposite ends to an upstanding part 32 on the boom 16 by a pivot pin 33 for pivotal movement about a transverse axis 34. The lever structure 31 includes a pair of levers 36, 37. The upper ends of the levers 36, 37 are pivotally connected to a rod 38 of an expansible and contractible strut in the form of a double acting hydraulic jack 39 by a transverse pin 41. The opposite ends of the levers 36, 37, disposed at opposite sides of the boom 16, are pivotally connected to a pair of dump links 42, 43 by pivot pins 44, 46 respectively. The corresponding forward ends of the dump links 42, 43 are pivotally connected to the upper rear portion of the bucket 19 by a transverse pivot pin 47. The cylinder 51 of the jack 39 is pivotally connected to the upper ends of connecting links 52, 57 and reversing links 53, 58 by a transverse pivot pin 54 for swinging movement about a common transverse axis 56. The bottom ends of links 52 and 57 are pivotally connected to the boom 16 by a transverse pivot pin 61 on a transverse pivot axis 62. The rear ends of reversing links 53, 58 are pivotally connected to the support 13 by a pair of transverse pins 66, 67 which are aligned on a transverse axis 68 disposed forwardly and above the transverse axis 18 on which the boom 16 is mounted on the frame 12 of the tractor.

Although a single linkage for the near side of the tractor has been illustrated and described it should be understood that a duplicate linkage is provided on the opposite side of the tractor.

As shown in FIG. 1 the bucket 19 has been loaded with material and the bucket rolled back on its axis 22 to a position preparatory to raising the bucket. In FIG. 3 the bucket 19 has been elevated by extension of the lift jack 23 and consequent swinging movement of the boom 16 to the position shown. The bucket dumping jack 39 has not been actuated; however, it will be noted that the bucket control linkage comprising the connecting links 52, 57 and reversing links 53, 58 have swung the jack pivot axis 56 rearwardly to automatically pivot the bucket 19 counterclockwise about its axis 22 as the boom 16 is raised. As the boom 16 is raised toward an approximate horizontal position the links 52, 57, 53, 58 will cause the bucket to swing substantially in unison with the boom. As the boom, in its upward swing, approaches a horizontal position the bucket control linkage, that is links 52, 57, 53, 58 will begin to pivot the bucket counterclockwise so as to keep the bucket in its illustrated material retaining position. The bucket control linkage continues to force the bucket counterclockwise relative to the boom as the boom is swung to its raised position shown in FIG. 3.

The illustrated linkage causes the bucket to scrape the dirt bank with greater ease and keeps the center of gravity as close as possible to the tractor during initial upward movement of the boom. By placing the loader linkage components in line, that is in a vertical longitudinal plane, the component stresses are minimized and the most effective application of hydraulic jack forces is achieved. The linkage has a relatively low silhouette thus facilitating operator visibility and minimizing tractor frame stress problems.

In loader design it is desirable to keep hydraulic hoses short. Thus it is desirable to connect the cylinder component of the jack to the tractor, rather than the rod end. This goal is achieved in the present design. In

addition, by using the expansion of the jack 39 to achieve roll back of the bucket, the greatest force available from the jack 39 is used to break out the load. This of course is a desirable parameter of loader design. it is also desired to keep dumping time to a minimum. This is achieved by using contraction of the jack 39 to achieve dumping of the bucket 19. The various features of the present invention contribute to a loader having desirable loading and handling characteristics. At the same time the novel loader linkage of this invention is comprised of components which are relatively easy and inexpensive to manufacture, thus providing the user with the advantages of an efficient tool at a reasonable cost.

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

1. in a tractor loader having a frame, the combination comprising:

a longitudinally extending boom pivotally connected to said frame on a first transverse axis, a bucket pivotallyconnected at its lower rear portion to the front end of said boom on a second transverse axis, a lift jack operatively interposed between said frame and said boom, a lever structure pivotally connected intermediate its upper and lower ends to an intermediate part of said boom on a third transverse axis, a dump link structure pivotally connected at one of its opposite ends to the upper rear portion of said bucket and pivotally connected at the other of its opposite ends to said lower end of said lever structure, an expansible and contractible strut pivotally connected at one of its opposite ends to said upper end of said lever structure, and linkage means interconnecting said strut, frame and boom including a first link pivotally connected at one of its opposite ends to said boom on a fourth transverse axis disposed forwardly of said first transverse axis,

a second link pivotally connected at one of its opposite ends to said frame on a fifth transverse axis disposed forwardly of said first transverse axis,

first pivot means pivotally interconnecting said first and second links on a transverse axis spaced from said fourth and fifth axes, and

second pivot means pivotally connecting the other end of said strut to one of said first and second links on a transverse axis spaced from said fourth and fifth axes whereby said strut is in overlying relation to said boom.

2. The invention of claim 1 wherein the transverse axis interconnecting said first and second links is the same transverse axis on which said strut and said one of said links are pivotally connected.

3. The invention of claim 2 wherein said first and second pivot means comprise a transverse pivot pin.

4. The invention of claim 1 wherein said fifth pivot axis is spaced above said first pivot axis.

5. The invention of claim 4 wherein the transverse axis interconnecting said first and second links is the same transverse axis on which said strut and said one of said links are pivotally connected.

6. The invention of claim 1 wherein said strut lies in the longitudinal vertical plane of said boom.

7. The invention of claim 6 wherein said lever structure includes levers on transversely opposite sides of said boom pivotally connected to the latter on said third axis and wherein said dump link structure includes dump links on transversely opposite sides of said boom having their corresponding opposite ends pivotally connected to said bucket and levers.

8. The invention of claim 6 wherein said linkage means includes a pair of first links on opposite transverse sides of said boom pivotally connected to said boom on said fourth axis,

a pair of second links disposed on the transversely outer sides of said first links and pivotally connected to said frame on said fifth axis,

said first pivot means pivotally interconnects said pairs of links, and

said second pivot means pivotally connects the other end of said strut to one of said pairs of first and second links. 1

9. The invention of claim 8 wherein said first and second pivot means comprise a transverse pivot pin.

10. The invention of claim 1 wherein said strut includes a double acting hydraulic jack having its rod end pivotally connected to said upper end of said lever structure and having its cylinder end pivotally connected by said second pivot means to one of said first and second links.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3211310 *Jul 9, 1962Oct 12, 1965Caterpillar Tractor CoTrip mechanism for automatically positioning vehicle loaders
US3464574 *Jan 8, 1968Sep 2, 1969Caterpillar Tractor CoLoader lift linkage
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4029226 *Apr 12, 1976Jun 14, 1977J. I. Case CompanyLinkage support system for material handling unit
US4046026 *Jan 5, 1976Sep 6, 1977Sveska Hymas AktiebolagLinkage and motion system, especially for accomplishing a swinging movement in equipment such as buckets for power shovels and the like
US4344734 *May 23, 1980Aug 17, 1982J. I. Case CompanySelf-leveling bucket linkage
US4364705 *Jul 7, 1980Dec 21, 1982J. I. Case CompanyLoader mechanism
US6699000 *Apr 23, 2001Mar 2, 2004J. C. Bamford Excavators LimitedMachine having a working arm
Classifications
U.S. Classification414/713, 414/715
International ClassificationE02F3/28, E02F3/34
Cooperative ClassificationE02F3/3411
European ClassificationE02F3/34L4
Legal Events
DateCodeEventDescription
Apr 18, 1985ASAssignment
Owner name: FIATALLIS EUROPE S.P.A., ZONA INDUSTRIALE SURBO, I
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:FIATALLIS NORTH AMERICA, INC., A DE CORP;REEL/FRAME:004389/0443
Effective date: 19850228