US3368705A - Overshot loader - Google Patents

Description

Feb. 13, 1968 H L ORVWG ETAL I 3,368,705

OVERSHOT LOADER Original Filed March 12, 1963 2 Sheets-Sheet 1 7 www INVENTORS /7. L. Dew/G LA. MOLBY Feb. 13, 1968 H. ORWIG ETAL 3,368,705

OVERSHOT LOADER Original Filed March -l2, 1963 2 Sheets-Sheet 2 IINVENTORS /2. 1. OR 'w/a L A. M01 BY BY 5 5 ATTORNEY United States Patent 3,368,705 OVERSHOT LOADER Herbert L. Orwig, Rochester, and Lloyd A. Molby, Batavia, N.Y., assignors, by mesne assignments, to Eaton Yale & Towne Inc., a corporation of Ohio Original application Mar. 12, 1963, Ser. No. 264,520, now Patent No. 3,252,605, dated May 24, 1966. Divided and this application Oct. 5, 1965, Ser. No. 513,879

5 Claims. (Cl. 214-765) ABSTRACT OF THE DISCLOSURE The body or frame of a vehicle is stabilized relative to an axle pivoted about a horizontal axis by a ram connected to the body and axle. A fluid circuit to the ram normally permits the ram to float but when the vehicle brakes are applied or during other conditions, the circuit to the ram is closed to lock the ram and thus stabilize the frame or body.

This invention relates to a shovel loader of the type known in industry as an overshot loader. Loaders of the particular class utilize a shovel or bucket that is mounted for swinging movement on the loader vehicle so as to bring the bucket from a position at the front of the vehicle where it is loaded, to an upper position rearward of the vehicle where it is dumped. Obviously, the bucket must be manipulated for loading, and must be manipulated for maintaining the load within the bucket until the bucket is carried to its dumping position.

Those skilled in the art fully appreciate that much effort has been made to simplify the effective movement of a shovel loader bucket in a vehicle of the class described. However, so far as we know, no completely satisfactory overshot loader has been developed. We believe that our invention contributes an overshot loader of extreme simplicity in construction while yielding extremely effective operation through novel controls we have conceived.

This application is a division of parent application Ser. No. 264,520 filed Mar. 12, 1963, now U.S. Patent 3,252,605.

As a feature of our invention, we mount the front axle of our loader for rocking movement to facilitate movement of the loader on uneven ground. At the same time, We provide means for relatively locking the front axle against this rocking movement to stabilize the loader during operation of the various arm and bucket controls. As still another feature, we fix the rear axle against rocking movement, so that when the bucket is in the elevated position substantially above the rear axle and the truck in the least stable condition, the fixed rear axle effectively stabilizes the truck against rocking. To provide a very rigid rear axle structure for this purpose, we preferably mount the wheels directly on the ends of the rear axle and effect steering by bodily rotating the axle and wheels about a central pivot which is fixed to the loader frame.

We have thus outlined rather broadly the more important features of our invention in order that the detailed description thereof that follows may be better understood, and in order that our contribution to the art may be better appreciated. There are, of course, additional features of our invention that will be described hereinafter and which will form the subject of the claims appended hereto. Those skilled in the art will appreciate that the conception on which our disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of our invention. It is important, therefore, that the claims be regarded as including such equivalent constructions as do not depart from the spirit and scope of our invention, in order to 3,368,705 Patented Feb. 13, 1968 prevent the appropriation of our invention by those skilled in the art.

In the drawings:

FIG. 1 shows diagrammatically the front axle and axle control circuit of our loader;

FIG. 2 shows in section the axle control valve;

FIG. 3 is a plan view showing the mounting of the rear axle; and

FIG. 4 is a side elevational view of the rear axle mounting.

Referring now more particularly to FIG. 1 of the drawings, we construct our novel loader with a main frame 10 on which are front and rear Wheels 11, 12, and a lifting arm that supports a bucket.

The front axle 91 is supported for rocking movement on a pivot 92 that is mounted on a front cross member 93 of the loader frame 10. As will be appreciated, the rocking of the axle 91 will facilitate the movements of my loader when it operates on uneven ground. We particularly utilize a hydraulic ram 94 that will control the rocking of axle 91. The ram 94 has a cylinder 95 pivoted through a pin 96 on one side of the frame 10, and a piston 97 that is pivoted to a bell crank lever 98. A pivot 99 supports the lever 98 for rotation relatively to the opposed side of frame 10. Bell crank lever 98 is also connected through a link 200 to an end portion of axle 91. The ram piston 97 then will move in cylinder 95 as axle 91 rocks on its pivot, as will be understood.

As shown in FIG. 1, hydraulic lines 201, 202 lead from opposed ends of ram cylinder 95 to a valve 203, shown in detail in FIG. 12. Valve 203 has separate passages 204, 205 through which each line 201, 202 normally communicates with a corresponding line 206, 207 which leads to the hydraulic reservoir 54. The fluid then can move in each of the lines 201, 202, enabling the ram piston 97 to move so that axle 91 can rock freely on its pivot 92. The valve 203 includes a plunger 208 that is effective when depressed to close each passage 204, 205, as shown in FIG. 2.

Our loader is equipped with a usual type of brake control 209, FIG. 1, that will be elfective when a pedal 211 is depressed to direct fluid pressure through a line 210 to apply the loader brakes, not shown. In our invention, we also direct the fluid pressure from the brake control 209 through a line 212 to a pressure actuated plunger 213. That plunger 213 will act against the valve plunger 208 and will move plunger 208 to position closing the passages 204, 205, when the operator of the truck depresses pedal 211.

With passages 204, 205 closed, fluid cannot move in the ram lines 201, 202, and therefore will lock the hydraulic ram 94. We prefer to install pressure relief valves 214, 215, on corresponding ram lines 201, 202. A discharge from either of those valves will move through a line 216 toward the reservoir 54.

Because ram 94 will be locked when the pedal 211 is depressed, it will be seen that the axle 91 cannot rock on its pivot 92 while the loader brakes are applied. The operator of the loader normally will hold the brakes applied during the digging and dumping operations of the loader, and therefore the axle 91 will automatically be locked and will effectively stabilize the loader at those times when stability is most to be desired.

When the fluid locks the ram 94, the relief valves 214, 215 will prevent a development of excessive pressure in the ram 94, as might happen under extreme conditions. One or the other of the relief valves 214, 215 will relieve the pressure partially, but not enough to elfect the stability of the loader to any considerable degree. While a relief of pressure may allow some slight movement of the axle, sufficient pressure will be retained in the ram 94 to lock the axle 91 after that movement.

To allow the operator to lock the front axle 91 against rocking movement without actuating the brakes, we provide a second control 216 which, when actuated, applies pressure through a line 217 to a second pressure actuated plunger 218. When actuated, the second pressure actuated plunger 218 also moves the valve plunger 208 to a position closing the passages 204, 205 to lock the hydraulic ram 94. The control 216 is conveniently mounted on the handle 58 which operates the lift control plunger 57 and is actuated by a lever 219.

To further stabilize the loader, particularly when the bucket is in an elevated position substantially over the rear axle 220, we fix the rear axle 220 against rocking movement, while allowing bodily rotation of the axle to effect steering of the loader. As shown in FIGS. 3 and 4, the rear wheels 12 are rotatably mounted on the outer ends of the rear axle 220 and the rear axle 220 is pivotally mounted through a bracket 221 on upper and lower vertical pivots 222, 223 which are secured to the main frame 10. By this arrangement, the axle 220 and wheels .12 may rotate bodily about the pivots 222, 223 to effect steering of the loader, while at the same time the axle and wheels are fixed against rocking movement. Such, steering of the rear axle 220 is conveniently effected through hydraulic rams 224, 225 which are provided on opposite sides of the loader and are pivoted at one end to the truck frame and at the other end to the axle 220. Thus, through extension of one ram and contraction of the other, the rear axle 220 and wheels 13 may be rotated about the pivots 222, 223 to effect steering of the loader.

The wheels 13 are driven from a differential 226 which is carried by the axle 220 and the vertical spacing of the two pivots 222, 223 allows a drive shaft 227 to extend to the differential 226. The drive shaft 227 is connected at one end to the differential 226 by a universal joint 228 and connected at the other end to a transmission 229 by a similar universal joint 230, whereby the rear axle 220 may be steered while power is supplied to drive the wheels 13.

From the description that we have made, we believe that the operation and the advantages of our novel overshot loader will be clearly understood. We believe, therefore, that those persons who are skilled in the art will understand the very considerable value of our contribution, and that the merits of our invention will be fully appreciated.

We now claim:

1. A loader of the class described, a main frame, a load lifting arm pivoted on said main frame, pairs of front and rear ground engaging wheels on which the main frame moves, a pivoted axle mounting one of said pairs of wheels to rock on the main frame about a horizontal axis when the frame moves over uneven ground, means mounting the other pair of wheels to pivot only about a vertical axis for steering the loader, a hydraulic ram having a piston and a cylinder, said ram being connected to the main frame and also connected to said pivoted axle, a normally open hydraulic circuit through which hydraulic fluid flows so as to allow the ram piston to move in the cylinder as the axle rocks freely on its pivot, and a valve for shutting off the flow of fluid in said circuit whereby to stabilize the main frame through locking of said ram and axle.

2. The combination as claimed in claim 1, in which said ram is connected to said pivoted axle by a linkage means.

3. The combination as claimed in claim 2, in which said linkage means includes a pivot pin fixed to said main frame.

4. In a combination of the class described, a main frame, a load lifting arm pivoted on said main frame, pairs of front and rear ground engaging Wheels on which the main frame moves, a fluid actuated brake system for said wheels including a hydraulic brake circuit and brake control, a pivoted axle mounting one of said pairs of wheels to rock on the main frame when the frame moves over uneven ground, a hydraulic ram having a piston and a cylinder connected to the main frame and to the axle, a normally open second hydraulic circuit through which hydraulic fluid flows so as to allow the ram piston to move in the cylinder as the axle rocks freely on its pivot, a valve controlling said second hydraulic circuit, and means actuated by said hydraulic brake circuit when said brake control is actuated to shut off the flow of fluid in said second circuit whereby to stabilize the main frame through locking of said ram and axle.

5. In a combination of the class described, a main frame, a first axle having ground engaging Wheels mounted thereon, a second axle spaced from said first axle and having ground engaging wheels mounted thereon and a differential through which said wheels may be driven, a load lifting arm pivoted on said main frame for pivotal movement from a lowered position extending toward said first axle and an elevated position extending upwardly above said second axle, means mounting said first axle for rocking movement on said main frame, means for selectively locking said first axle against rocking movement, means mounting said second axle on the main frame for steering rotation around a vertical axis while preventing rocking movement of said second axle whereby to stabilize the main frame when said arm is in an elevated position, means for effective steering rotation of said second axle, and a drive shaft connected with the differential of said second axle for driving said wheels mounted thereon, said drive shaft being connected to said differential through a universal joint to permit said steering rotation of said second axle.

References Cited UNITED STATES PATENTS 2,694,581 11/1954 Helmle 280-611 2,835,397 5/1958 Wagner 214774 3,077,952 2/ 1963 Neises 2806 3,171,556 3/1965 Brekelbaum et al. 214765 3,184,867 5/1965 Symmank 2806.l1 X

HUGO O. SCHULZ, Primary Examiner.

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