US3803925A

US3803925A - Rack and pinion swing actuator for a backhoe

Info

Publication number: US3803925A
Application number: US00280587A
Authority: US
Inventors: J Jackson
Original assignee: Caterpillar Tractor Co
Current assignee: Caterpillar Inc
Priority date: 1972-08-14
Filing date: 1972-08-14
Publication date: 1974-04-16
Anticipated expiration: 1991-04-16
Also published as: GB1395847A; BE803601A; JPS5743700B2; CA976384A; JPS4958266A

Abstract

There is disclosed a backhoe having a readily removable swing actuator. The swing actuator comprises a reaction shaft receivable in a socket on a swing support bracket that is operative to non-rotatably retain the reaction shaft. A pinion is secured to the reaction shaft and a housing rotatably mounted on the reaction shaft and encompassing the pinion gear. A linear hydraulic motor is drivingly connected to the pinion gear and to the housing to operatively swing the housing around the reaction shaft. Means are provided for detachably coupling the housing to a pivotally mounted boom swing frame to transmit torque from the housing to the boom swing frame.

Description

iinited States Patent [191 .1 ackson RACK AND PINION SWING ACTUATOR FOR A BACKHOE [75] Inventor: James S. Jackson, Peoria, 111.

[73] Assignee: Caterpillar Tractor Co., Peoria, 111.

[22] Filed: Aug. 14, 1972 [21] Appl. No.: 280,587

[52] US. Cl. 74/89.17, 214/138 R [51] Int. Cl. F16h 27/02 [58] Field of Search 74/8917, 422; 37/103;

[56] References Cited UNITED STATES PATENTS 2,978,116 4/1961 Wells et al. 214/138 R 3,040,717 6/1962 Rumseym 74/89.l7

3,165,842 l/1965 Holopainen 214/138 R 3,278,046 10/1966 Shumake'r 214/138 R 3,436,849 4/1969 Haynes 214/138 R 3,493,135 2/1970 Novotny 214/138 R Primary Examiner-Benjamin W. Wyche Assistant ExamznerWesley S. Ratliff, Jr.

Attorney, Agent, or Firm--Fryer, Tjensvold, Phillips & Lempio [5 7] ABSTRACT There is disclosed a backhoe having a readily removable swing actuator. The swing actuator comprises a reaction shaft receivable in a socket on a swing sup- 5 Claims, 4 Drawing Figures .--'MENTEBAPR 16 1914 V 13,803; 925

v sum 1 0f 4 RACK AND rumor: SWING ACTUATOR FOR A BACKHOE BACKGROUND OF THE INVENTION The present invention relates to backhoes and pertains more particularly to a readily removable swing actuator for a backhoe.

Backhoes are normally mounted on a transversely supported frame attached to the rear of a tractor or similar vehicle, and have a boom swing frame pivotally mounted to the support frame for swinging movement about a vertically disposed pivot axis. A hydraulic motor is normally secured to the frame and coupled to the boom for swinging it about the pivotal axis. Various types of hydraulic motors and drives are employed for such application. One desirable form of such actuator comprises a linear hydraulic motor with a rack and pinion drive for transmitting the driving force to the boom. These motors and drive arrangements occasionally break down and must be removed and replaced or removed and repaired.

Known actuators of this type are generally built into the support frame, and are such an integral part of the support structure that the entire boom support structure must often be removed in order to remove or repair the swing actuator. This requires that the backhoe be transported to a shop that is equipped to perform this work. Such action and the manner of construction result in considerable down time in order to effect such repair or replacement. This results in such repair being extremely time consuming as well as expensive.

A swing actuator of the rack and pinion type which is built into the support structure is exemplified by U.S. Pat. No. 2,980,401, issued Oct. 13, 1959 to H]. Schroeder. Anothertype of swing actuator having a readily detachable swing motor is illustrated or disclosed in U.S. Pat. No. 2,978,116, issued Apr. 4, 1961 to BL. Wells et al. This Wells patent illustrates one approach to solving the problem of expensive down time, should the hydraulic swing actuator fail.

SUMMARY AND OBJECTS OF THE INVENTION It is the primary object of the present invention to provide a swing actuator for a backhoe that is readily detachable from the backhoe for repair or replacement without the necessity for disassembly of the components of the backhoe.

Another object of the present invention is to provide a rack and pinion type swing actuator for a backhoe with novel coupling meansto permit ready attachment and detachment to a backhoe without the necessity for disassembly. I

A further object of the present invention is to provide a novel rack and pinion swing actuator and coupling means for detachably coupling the actuator for swing actuation of a backhoe.

In accordance with a primary aspect of the present invention, there is provided a rack and pinion type swing actuator having a reaction shaft about which the actuator swings to actuate or swing the backhoe linkage. The reaction shaft is slidably received in a socket on the swing actuator support wherein the reaction shaft is held in non-rotatable position. The reaction shaft holding socket is built into the stationary support frame for the backhoe, and permits removal and replacement of the actuator without disturbing the relationship of any of the other components of the backhoe assembly. Simple coupling means attaches or couples the swing housing to the boom swing frame of the backhoe to transmit torque thereto.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects and advantages of this invention will become apparent from the following specification when read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a side elevational view of a backhoe embodying the principles of the present invention;

FIG. 2 is a detailed elevational view of a pivotal support in combination with a swing actuator in accordance with the present invention;

FIG. 3 is a sectional view, taken generally along lines IIIIII of FIG. 4; and,

FIG. 4 is a top view, with portions broken away, of the swing actuator in accordance with the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to the drawings, and particularly to FIG. 1, there is illustrated a swing actuator generally designated by the numeral 10, operatively connected between a swing frame I2 and a stationary support frame 14 of a backhoe, generally designated by the numeral 16. The stationary support frame 14 is secured in a suitable manner to' the back end of a suitable vehicle such as a tractor or loader 18.

The swing frame or support 12 is pivotally supported to the stationary frame 14 for pivotal movement about a vertical axis, and supports the bucket linkage comprising a boom 20 and a stick 22, to which is pivotally supported a suitable bucket 24. These linkages are all manipulated by the usual hydraulic rams as illustrated.

The

frames

12 and 14, as best seen in FIG. 2, arepivotally connected together by means of upper and lower brackets. The lower bracket generally comprises a rearward extending bracket member 26 received between the arms of a bifurcated bracket 28 and pivotally connected together by means of a pivot pin 30. The upper bracket comprises bifurcated member or bracket 32, extending rearwardly from stationary support member 14, and receiving the bracket member 34 extending forward from the swing frame 12. The bracket mem bers are pivotally connected together by means of a hollow pin or sleeve 36.

Turning now to FIG. 3, it is seen that the sleeve 36 extends through bores 38 of the bifurcated member 32 and journals bracket member 34 thereto by means of suitable bearing means 40. The sleeve 36 is formed with an internal spline 42, and is non-rotatably secured to the bifurcated bracket member 32 by means of a flange 44 having a stub shaft 46 with splines projecting into the spline bore 42 of the sleeve 36. The flange 44 is non-rotatably secured to the bracket 32 by suitable means such as bolts 48 and dowels or pins 50. The sleeve 36, together with flange 44, define a socket for receiving and non-rotatably supporting a reaction shaft to be described.

Referring now to FIGS. 3 and 4, there is illustrated a preferred embodiment of the swing actuator of the present invention, comprising generally a housing 52 having a removable cover 54 secured thereto in a suitable manner such as by screws or bolts 56. A reaction shaft 58 is rotatably mounted in the housing 52 such as by suitable bearing means 60 and 62, and has suitable seal means 64.

The reaction shaft 58 includes splines 66 extending into and engaging splines 42 of sleeve 36, so as to nonrotatably secure the shaft 58 with respect to the stationary frame and bracket members 32. A pinion gear 68 is non-rotatably secured in a suitable manner to the reaction shaft 58 and is drivingly engaged by a reciprocable rack member 70. The rack 70 is formed between a pair of pistons, only one of which is shown at 72, and which are reciprocally mounted in cylinders 74 and 76, which are coaxially disposed in opposed relationship and suitably secured such as by means of

bolts

78 and 80 to the housing 52. Suitable inlet ports 82 and 84 are provided for the introduction of pressurized fluid into the cylinders 74 and 76 for operation of the pistons 72.

The housing 52 is provided with suitable brackets 86 and 88, extending outward therefrom and operatively connected such as by means of

bolts

90 and 92 to the swing frame 12. This bracket means provides appropriate means for operatively connecting the swing actuator to the swing frame 12 for transmitting torque or force thereto for swinging the frame about its pivot point or pivot mountings.

As can be seen especially from FIG. 3, the swing actuator unit may be completely removed simply by removing

bolts

90 and 92 and lifting the housing 52 upward to remove reaction shaft 58 from the socket defined by the central bore of the sleeve 36. The removal of the actuating unit in no way affects the support by means of the pivot brackets of the support or swing frame 12.

As can be readily seen from FIG. 4, the introduction of pressurized fluid into either one of cylinders 74 or 76, forcing the rack 70 in either direction with respect to the housing 52, will apply a force to the reaction shaft 58 by way of pinion gear 68, swinging the housing 52 about the reaction shaft. This swinging of the housing transmits force directly to the swing frame 12 to likewise swing the backhoe boom about the swing axis.

Thus, it can be seen from the above description that there is disclosed a novel swing actuating apparatus and support assembly for a backhoe that permits the ready removal of the swing actuator without affecting support of the backhoe assembly. More specifically, there is disclosed a rack and pinion swing actuator having a reaction shaft non-rotatably received in a socket formed in stationary support means and operative to transmit torque to the boom.

While the present invention has been disclosed with respect to a single embodiment, it is apparent that numerous changes and modifications may be made in the illustrated structure without departing from the spirit and scope of the present invention as defined in the appended claims.

What is claimed is:

l. A pivotal support bracket assembly for pivotally supporting a backhoe boom for swinging movement about a vertical axis, said assembly comprising:

stationary bracket and a movable bracket pivotally supported by an internally splined sleeve to said stationary bracket;

a stationary splined reaction shaft slidably extending into said sleeve and non-rotatably coupled thereto:

a housing rotatably supported on said shaft;

a linear actuator mounted in said housing and drivingly connected to said shaft;

a stub shaft having splines formed thereon for engaging said splines in said sleeve;

a flange formed on said stub shaft for securing said shaft to said stationary bracket; and,

means operatively connecting said housing to said movable bracket.

2. A detachable swing actuator assembly for a backhoe and the like, said assembly comprising:

a vertically oriented swivel mount comprising a fixed bifurcated first bracket comprising upper and lower spaced members having a vertically oriented cylindrical bore formed therein;

a hollow pin having internal splines formed therein mounted in said bore and pivotally mounting a second bracket member to said first bracket;

means non-rotatably securing said hollow pin to said bracket;

a swing actuator comprising a housing, a reaction shaft including a pinion rotatably mounted in said housing and a linear hydraulic actuator including a rack drivingly connected to said reaction shaft;

said reaction shaft having a splined portion extending into and non-rotatably connected by cooperative engagement of said splines to said hollow pin; and,

means connecting said housing to said second bracket. 3. A swing drive actuator for a backhoe comprising:

a bracket for pivotally supporting a boom for swinging movement about a vertical axis;

said bracket including means defining a nonrotatable socket;

a reaction shaft fixedly receivable in said socket;

a pinion coupled to said reaction shaft;

a housing rotatably mounted on said shaft and enclosing said pinion;

a linear hydraulic motor attached to said housing and including a rack drivingly connecting said hydraulic motor to said pinion; and,

means for connecting said housing for transmitting torque to a boom pivotally supported in said bracket.

4. A swing drive actuator for a backhoe comprising:

a bracket for pivotally supporting a boom for swinging movement about a vertical axis; said bracket including a pin having an axial bore defining a non-rotatable socket having splines formed therein;

a flange securing said pin to said bracket;

a reaction shaft fixedly receivable in said socket;

a pinion coupled to said reaction shaft;

a housing rotatably mounted on said shaft and enclosing said pinion;

5. A swing drive actuator for a backhoe comprising:

a bracket for pivotally supporting a boom for swinging movement about a vertical axis:

said bracket including a pin having an axial bore defining a non-rotatable socking having splines formed therein;

said pin comprises a pivotal support for said bracket;

a reaction shaft fixedly receivable in said socket;

bracket.

UNITED STATES P TENT oFFICE f: CERTIFICATE OF CURRECTION Patent No. 3,803,925 Dated Anril 16. 1974 mventorm) James 5 Jackson,

i It is certified that error appears in the above-identified patent and that said Letters Patent are'hereby corrected as shown below:

Claim 5, line -6, "soaking" is corrected to read -socket-- Signed and sealed this 8th day of October 1974 (SEAL) Attest: McCOY M. GIBSON 'JR. c. MARSHALL DANN Attesting Officer Commissioner of Patents FORM PC4050 (10-69) sco c 603.75-p59 :r us, eovzauuzn r PRINTING OFFICE: [969 o-ass-au

Claims

1. A pivotal support bracket assembly for pivotally supporting a backhoe boom for swinging movement about a vertical axis, said assembly comprising: stationary bracket and a movable bracket pivotally supported by an internally splined sleeve to said stationary bracket; a stationary splined reaction shaft slidably extending into said sleeve and non-rotatably coupled thereto: a housing rotatably supported on said shaft; a linear actuator mounted in said housing and drivingly connected to said shaft; a stub shaft having splines formed thereon for engaging said splines in said sleeve; a flange formed on said stub shaft for securing said shaft to said stationary bracket; and, means operatively connecting said housing to said movable bracket.

2. A detachable swing actuator assembly for a backhoe and the like, said assembly comprising: a vertically oriented swivel mount comprising a fixed bifurcated first bracket comprising upper and lower spaced members having a vertically oriented cylindrical bore formed therein; a hollow pin having internal splines formed therein mounted in said bore and pivotally mounting a second bracket member to said first bracket; means non-rotatably securing said hollow pin to said bracket; a swing actuator comprising a housing, a reaction shaft including a pinion rotatably mounted in said housing and a linear hydraulic actuator including a rack drivIngly connected to said reaction shaft; said reaction shaft having a splined portion extending into and non-rotatably connected by cooperative engagement of said splines to said hollow pin; and, means connecting said housing to said second bracket.

3. A swing drive actuator for a backhoe comprising: a bracket for pivotally supporting a boom for swinging movement about a vertical axis; said bracket including means defining a non-rotatable socket; a reaction shaft fixedly receivable in said socket; a pinion coupled to said reaction shaft; a housing rotatably mounted on said shaft and enclosing said pinion; a linear hydraulic motor attached to said housing and including a rack drivingly connecting said hydraulic motor to said pinion; and, means for connecting said housing for transmitting torque to a boom pivotally supported in said bracket.

4. A swing drive actuator for a backhoe comprising: a bracket for pivotally supporting a boom for swinging movement about a vertical axis; said bracket including a pin having an axial bore defining a non-rotatable socket having splines formed therein; a flange securing said pin to said bracket; a reaction shaft fixedly receivable in said socket; a pinion coupled to said reaction shaft; a housing rotatably mounted on said shaft and enclosing said pinion; a linear hydraulic motor attached to said housing and including a rack drivingly connecting said hydraulic motor to said pinion; and, means for connecting said housing for transmitting torque to a boom pivotally supported in said bracket.

5. A swing drive actuator for a backhoe comprising: a bracket for pivotally supporting a boom for swinging movement about a vertical axis: said bracket including a pin having an axial bore defining a non-rotatable socking having splines formed therein; said pin comprises a pivotal support for said bracket; a reaction shaft fixedly receivable in said socket; a pinion coupled to said reaction shaft; a housing rotatably mounted on said shaft and enclosing said pinion; a linear hydraulic motor attached to said housing and including a rack drivingly connecting said hydraulic motor to said pinion; and, means for connecting said housing for transmitting torque to a boom pivotally supported in said bracket.