US2022181A - Hydraulic hoist for dump bodies - Google Patents

Description

NOV. 26, 1935. P BRlcK HYDRAULIC HOIST FOR DUMP BODIES 2 Sheets-Sheet 1 Filed April 21, 1934 Nov. 26, 1935. P. A. BRICK HYDRAULIC HOIST FOR DUMP BODIES 2 Sheets-Sheet 2 Filed April 21, 1934 ing the travel of the vehicle carrying said body and Patented Nov. 26, 1935 UNITED STATES 2,022,181 HYDRAULIC HOIST FOR DUMP BODIES Perry A. Brick, Galion, Ohio,

Perfection Steel Body Company,

a corporation Application April 21,

1 Claim.

My invention involves certain improvements in hydraulic hoist mechanisms of the type which are commonly used today for incorporation in automotive vehicles or trucks for the purpose of lifting dump bodies mounted upon the truck frame.

The special construction of hydraulic hoist employed by me utilizes a cylinder for the reception of the motive fluid, preferably oil, piston means mounted in said cylinder and connected by its piston rod; to an operating head exterior to the cylinder, together with linkage connections intermediate said operating head and the body which is to be raised and lowered, whereby the lifting pressure derived from the fluid in the cylinder may be transmitted through the links to the said body for elevating the latter. The operating head according to my construction is equipped with rollers to travel upon tracks or rails mounted on the frame of the vehicle in the back and front movement of the head for the elevating and lowering movements of the body as caused by the link connections therewith.

Involved in my invention is a peculiar arrangement and mounting for the rollers carried by the operating head such that the thrust of the links which converge toward each other at the points of connection with the head will in no way be transmitted to the rollers so as to interfere withthe freedom of action of the latter in their travel upon therails or tracks provided therefor. Additionally .I provide a. special mounting for the cylinder and piston actuating unit such that the cylinder has a certain amount of freedom to rotate about the longitudinal axis thereof and such that there is provided what may be termed a three-point suspension mounting for the cylinder whereby to relieve the cylinder as-- sembly from any strains that might be set up incident to the weaving of the truck frame-under unequal stresses or pressures that may be received thereon in the operation of elevating and lowerthe dump body or such as may be caused by cylinder assembly over uneven surfaces.

Another feature of my invention comprises a special form of stop and detent devices controlling the extent of movement of the operating head by which the lifting links are actuated and likewise having a detaining function in reference to preventing liability of unauthorized or lifting movement of the operating head off of the operating track due to the tendency of the dump body to shift beyond its pivot in the dumping operation, Liability of bending of the piston rod for actuating the operating head is thus avoided.

Still another feature of the invention resides in the provision in the cylinder assembly of a special spring arrangement cooperating with the assignor to The Galion, Ohio,

1934, Serial No. 721,824

actuating piston for the operating head in such a manner, as totend to move the dump body downwardly at the end of the elevating structure of the piston and head, the said spring having suficient tension to start the body back to its lowered position when the cylinder pressure is relieved. Since the body is usually raised-almost to the vertical to afford a proper clearing or dumping action of the contents thereof, devices of this type prior to my invention have a tendency for the body to remain in its upraised position after the pressure is relieved and this tendency is obviated by me through the employment of the spring means above referred to.

A thorough understanding of the features of novelty of the present invention will be had upon reference tothe following description and the accompanying drawings, in which,-

Figure l is a. perspective View of an automo- 'tive vehicle frame and dump body construction 2 adapted thereto, illustrating the mechanism of the invention in combination therewith.

' Figure 2 is a side elevation of the parts illustrated' in Figure 1, the dump body omitted and the cylinder parts being broken away and shown 25 in section. I

Figure 3 is a top plan view of a somewhat fragmentary nature as regards. the frame construction, illustrating the parts shown in Figure 2 more fully. p

Since the invention is applicable to various types of chassis or frame structures of dumping trucks, the frame construction per se is not a material feature of the invention save as it is combined with the parts of the cylinder, operating head, lifting links, and track arrangements that will be more fully set forth shortly. In the drawings the dumping body illustrated is designated A and may be any one of many different types commonly used. It is pivotally mounted 40 accordingto this invention may be conventional 45 save and except in respect to the employment of longitudinal rails or track members 4, the said track members being connected at the front of the chassis with a. cross member 5 and at the rear portion of the chassis with a cross member fi located some distance in advance of the axis means 3 previously referred to.

At the front portion of the chassis or frame of the vehicle is disposed the pump 1 which may be of a known type adapted to be operated by suitable shaft means partially shown at 8, the latter to be connected with the power take-off adapted to be attached to the truck transmission means, this feature of construction not, however, being a part of the present invention, as

previously indicated. From the pump 1 an intake pipe 9 leads to the front end of the cylinder assembly which includes the cylinder I0, said pipe 9 being connected with a coupling supported by a trunnion I I carried by-and rigidly fastened to the head at the high pressure end of the cylinder. The trunnion II is hollow so that the pipe line 9 may conduct the oil therethrough into the high pressure end of the cylinder I as will be obvious. However, it is notable that the trunnion II is substantially concentric with the axis of the cylinder I 0 and free to turn a bearing on the cylinder supporting member I 2 which takes the form of an angle plate rigidly mounted upon the front ends of the track members 4 and frame sides 2, the vertical flange of said angle plate having the said bearing formed therein. Thus the high pressure end of the cylinder II] has a one-point suspension or supporting mounting. At the rear end thereof, the cylinder I0 is carried by special separate brackets is fastened to the inner sides of the track members 4 at corresponding outer ends and fastened to the rear cylinder head I 4 at their corresponding inner ends, as well seen in Figure 2, the parts 52 and I3 affording a three-point suspension mounting for the cylinder III.

In the cylinder I0 is mounted the pressure operated piston I5 and this piston has the customary piston rod I6 which projects through the rear end or head I4 of the cylinder and carrying thereon exterior to thecylinder the hollow sleevelike operating head I I. This operating head I! is mounted between the lifting links I8 that connect with a roller shaft I9 upon which rollers 20 are mounted, said rollers being free to travel longitudinally of the track members 4. It is notable that the links I8 converge forwardly toward their points of connection with the roller shaft I9 so that the thrust of the said links toward each other is transmitted directly to the crosshead I1 and shaft I9, leaving the rollers 20 entirely free to take care of the vertical component of the thrust action. In other words, there is no tendency on the part of the thrust component ofthe links I8 to interfere with the free turning of the rollers 20 and the stress set up in the shaft I is purely shear as compared with prior devices of this type, wherein the lifting links employed are so'attached usually outside of the rollers as to produce bending stresses in the shaft means that corresponds with the shaft I9 of the present invention, not to mention addition thereto, disadvantageous thrusts against the ends of the rollers, all of which difficulties are obviated by the present improvements.

It is notable that near the rear end of the tracks 4 and carried by the cross member 6, is a combined stop and detent member 2|, the vertical portion of which is the stop element, and the upper curved hook 2la of which constitutes the detent member. The operating head I! is adapted to abut with the stop member 2| when the dumping body A has been elevated to its highest point for dumping, the movement of the cross'head rearwardly for dumping purposes being thus limited. At the same time the hook portion 2 la of the stop member 2| engages over the operating head I! and thus the'part 2I2Ia serves not only to limit the piston travel under the pressure actuation of the piston I5, but also prevents the 'crosshead I! from being lifted off the track members 4 by reason of the tendency and rotatively mounted in said cross plate, and brackets secured to the spaced'members aforeof the body A to continue movement rearwardly beyond its limit of elevating action under the actuating force of the piston I5 and pressure fluid in the cylinder I 0.

Within the cylinder I0 and mounted upon the piston rod I6 at the front side of the piston I5 is a coiled spring 22 which encircles the piston rod. This spring moves rearwardly with the piston I 5 and piston rod I6 during the pressure stroke for elevating the'dump body A and the rear end of the 10 spring 22 finally abuts with the head I4 at the rear end. of the cylinder I0 and becomes compressed during the final movement of the dump body A in reaching its dumping limit of travel.

Since the weight of the dump body is not always sufficient to start the body back to its original or lowered normal position when the cylinder pressure in the cylinder I0 is relieved, it will be seen that the compressed spring 9 performs an actuating function upon relief of said pressure such as will furnish sufficient force to move the piston i5 forwardly as soon as the lifting pressure is released, thereby to positively cause the dump body-A to start its downward movement at such time.

.By reason of the three-point suspension or mounting of the cylinder assembly described, it is evident that strains will not be set up in the cylinder assembly by reason of any weaving or distortion of the truck frame in the practical use of the device of the invention.

At a predetermined point in the rearward movement of the piston I5 acted upon by the fluid pressure medium, said piston closes the low pressure port 23 near the rear end of the cylinder 35 with which port connects the low pressure pipe line 24. This action of the piston in closing the port 23 limits the stroke or travel of the piston and of course correspondinglylimits the forward dumping movement. of the dump body A. There- 40 afterthe pressure on the-front side of the piston may be released in the customary way. to provide for the downward movement of the dump body in an obvious manner.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is

In a dumping vehicle of. the class described,

the combination of a dump body, a chassis upon which the dump body is supported, mechanism for raising and lowering the dump body, including lifting links, a hydraulic'cylinder and piston assembly connected to the lifting links comprising a cylinder, a piston therein, a piston rod eX- tending from the. piston through an end of the cylinder, an operating head connected with said piston rod and attached to the lifting links for actuation thereof, spaced members carried by the chassis between which the cylinder, piston and piston rod assembly is disposed, a cross plate carried by said spaced members, a hollow trunnion to receive a pressure line connection carried by one end of the cylinder at the axis of the latter

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