US808655A - Hydraulic hoist. - Google Patents

Description

PATENTED JAN. 2, 1906.

U. HARVEY. HYDRAULIC HUI-ST. APPLICATION FILED AUG, 22, 1904.

A TTORNE Y5.

WITNESSES UNITED sTATEs PATENT OFFICE.

HYDRAULIC HOIST.

Specification of Letters Patent.

latented Jan. 2, 1906.

Application filed August 22, 1904. Serial No. 221,737.

To all whom it may concern.-

Be it kncwn that I, URBAN HARVEY, stationed at Baltimore, in the State of Maryland,

have invented a certain new and useful Improvement in Hydraulic Hoists, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings.

My invention relates to hydraulic motors, and has for its object the construction of a motor of this type that shall be self-contained, simple, compact, and economical in construction and effective in operation.

The invention may be defined as consisting generally in the combinations of elements embodied in the claims hereto annexed.

Referring to the drawings, Figure 1 represents a longitudinal sectional view through a form of motor embodying my invention. Fig. 2 represents a transverse section on the line 2 2 of Fig. 1. Fig. 3 represents a transverse section on the line 3 3 of Fig. 1. Fig.

- 4 represents a detail view of a form of check valve which I employ with my apparatus. Fig. 5 is a detail, partly in section and partly in elevation, showing a construction of piston which I employ in my apparatus. Fig. 6 represents a sectional view of a modification of the top of the casing of Fig. l, and Fig. 7 is an enlarged plan view of the top of the bushing and ball-valve.

Describing the parts by reference characters, 1 represents a casing which is preferably of elliptical form in transverse section, as shown in Fig. 2. This casing is provided with two bores 2 and 3, the former constituting a cylinder wherein the motor-piston 1 operates and the latter constituting the receptacle for the motive fluid. At the lower end the wall of the casing is thickened, as shown at 5, and is extended beyond the cylinder and receptacle to form a passage-way 6, by means of which communication is established between the receptacle and the cylinder. A plate 7, suitably secured to the casing, as by screws 8, covers the end of the casing and completes the passage-way.

In order to increase the capacity of the receptacle 3 without increasing the width of the casing, I prefer to make said receptacle elliptical in form, as appears in Fig. 2. The purpose of enlarging the receptacle 3 will be explained hereinafter.

In constructing a self-contained hoist it is an important object to be able to employ a motor-piston of relatively large area compared with the power or pump piston and at the same time not to render the hoist as a whole bulky or of inconvenient form by the provision of receptacles separate from the motorcasing and communicating with the pumpcylinder. To this end I have provided a cylinder 9 within the receptacle 3. This cylinder may be of any desired diameter to cooperate with the piston 10 therein to produce the re-' quired ratio between the size of the said piston and that of the motor-piston 4. The lower end of the cylinder 9 is adapted to cooperate with a seat 11 of any suitable material to form therewith a valve for establishing or cutting off the communication between the receptacle 3 and the outlet 12 from the said receptacle, which communicates with the passage-way 6. The piston 10 fits snugly within the cylinder 9, said cylinder being provided with bushings 13 14 at each end, respectively, to limit the stroke of the piston. In order to guide and center the cylinder above the outlet 12 and to insure its proper action as a valve in connection with the seat 11 above said outlet, the receptacle 3 is provided with inwardly-projecting lugs 15, between which the cylinder is guided and centered.

Where the receptacle is long relatively to the length of the cylinder 9, I provide a stop to limit the upward movement of said cylinder. This stop is conveniently provided by means of a boss 16, projecting inwardly from the interior of the receptacle 3 a somewhat slighter distance than the projection of the lugs 15 and having a stop-pin 17 threaded thereinto. The said pin is provided with an inwardly-extending portion 18, which engages the upper end of the cylinder to limit the upward movement of the same.

The cylinder 2 communicates with the passage-way 6 by means of a valve-controlled opening 19. An upwardly-opening checkvalve 20 is provided for this opening, said check-valve being provided with a stem 21, having therein a slot 22, within which extends the end of a pin 23, which is screwed into the lower end of the casing 1. The purpose of this pin and slot is to limit the opening of the valve 20 and to guide and hold said valve in working position. The plate 7 is provided with threaded bosses 24 25, through which extend, respectively, the piston-rod 26 and the operating rod or pin 27 for the checkvalve. Packing- nuts 28 and 280 are provided for said rod and pin,- respectively. Suitably secured to the plate 7, as by means of athreaded base 29 engaging the threads of the boss 24, is a bracket 30, the purpose of which will be hereinafter explained.

As a convenient means for tightening the piston packings without disassembling the motor I have provided the constructions shown in Figs. 1 and 5. The piston-rod 26 and the lifting-rod 31 are made hollow. The former bears against the shoulder 32, the latter against the washer 33. Through the rod 26 extends the rod 330, the latter being provided with a head 34, engaging the metallic washer 35. Between said washer and the shoulder 32 are placed the packing 36, of soft material, and the cup-leather 37. Through the hollow rod 31 extends the rod 38, said rod being secured to the washer 39, which in turn engages the packing 40. Between the packing 40 and the washer 33 is interposed other packing 41. It will be apparent from the above description that, by merely setting up the nuts 42, 43 on the ends of the rods 330 and 39, respectively, the packings of the pistons 10 and 4 may be readily adjusted.

The upper end of the receptacle 3 may be closed, as by a plug 44, which may be threaded into the upper end of said receptacle, the upper end being made circular to permit the insertion of the plug. This plug is provided with a squared end 55 for the reception of a wrench. A passage-way is provided through this plug for the passage of air from and to the receptacle 3 as the level of the liquid in said receptacle rises or falls. This passage comprises a vertical branch 45, which may be provided in a bushing 46, screwed into the plug and a horizontal branch 47. This vertical branch is preferably square in section and is partially closed by a ball-valve 450, adapted to seat in the frusto-conical chamber 440 above the vertical branch. The bushing may be provided with an extension 48, by means of which it may be screwed in place and afterward secured against rotation by means of a screw 480.

Formed with the upper end of the casing and surrounding the rod 31 and the extension 55 of the plug is a concave cup 49. By means of this cup any liquid which may escape by leakage around the operating-rod may flow back through the passages 47 and 45 into the receptacle 3. The upper end of the liftingrod is provided with a suitable connection 50, carrying a pin 51, by means of which the lifting-rod may be connected with and its motion may be communicated to any object it maybe desirable to operate upon. The top of the cup may be provided with a covering-plate. (Not shown.)

In operation the piston-rod 26 is elevated and the piston 10 rises, carrying with it by frictional engagement the cylinder 9 until the latter is engaged by the pin 18. This causes an open space to be left between the bottom of the cylinder and the outlet from the receptacle. Further movement of the piston 10 causes liquid to be drawn into the cylinder 9. The operator then pulls down upon the handle 52. This causes thecylinder 9 to engage its seat 11, and the contents of said cylinder may then be forced through the outlet 12, passage-way 6, and valve-controlled opening 19 into the cylinder 2. This operation may be repeated as many times as will be necessary to elevate the lifting-rod 31 to its desired position, the number of such operations depending upon the ratio between the sizes of the pistons 10 and 4 and the distance which it is desired to move the latter piston. The piston-rod 26 may then be elevated until the lug 53 thereon is above the lower end of the bracket 30 and may then be turned to bring said lug into engagement with said bracket, as shown in Figs. 1 and 3. With the parts in this position when it is desired to lower the device, which has been raised by the liftingrod 31, it is only necessary to'operate the pin 27, as by screwing the same through the plate 7 by means ofits handle 54, to unseat the valve 20. The liquid in the cylinder is then forced into the receptacle 3, and the motor-piston descends with a speed dependent upon the opening of the valve 20 and the downward pressure on the rod 31. in condition to repeat the above operation. By making the receptacle 3 of elliptical form there will remain suflicient motive liquid in it after the piston 4 has been elevated to insure the filling of the cylinder 9 with the motive liquid and the sealing of the lower end of said cylinder by the liquid to exclude air from the cylinder.

The pin 27 is provided with ahead 270 therein, which may be formed by upsetting the end of said pin after it has been inserted through the plate 7 to prevent said pin from being accidentally unscrewed. The plate may be countersunk to receive said head. A stop portion 271 on said pin limits the extent of opening of the valve 20.

For convenience of operation the casing may be provided with trunnions 56, by means of which it may be readily applied to any vertical wall, as the coaming of a skylight, and may be sufficiently spaced'from said wall to give a sufficient range of movement to conveniently operate the lifting-rod'of said skylight without the intervention of a connecting-link.

By making the passage through the bushing square in section said opening will not be fully closed by the ball 450, and air, as well as the liquid that leaks around the lifting-rod, may flow through said passage, with the ball resting on the bushing. Should the casing be inverted or the liquid be otherwise forced quickly toward the top of the casing,

The device will then be IIO the ball will be seated in the upper end of the recess 44:0 and prevent the escape of such liquid.

The embodiment of my invention herein disclosed is simple and convenient in application and while particularly applicable to lifting devicessuch as skylights, trap-doors,

and the likemay of course be employed wherever desirable to use a self-contained hoist for applying hydraulic power to any object.

Instead of widening the top of the receptacle, as will be necessary to screw the plug 414 thereinto, I may retain the elliptical shape of the casing by providing a shoulder 57, as shown in Fig. 6, wherein the plug 441, somewhat smaller than the plug L4, may be introduced. The bushing M50 in said plug may be unprovided with the extension 48. (Shown in Fig. 1.)

While I have described my invention in detail, it will be obvious that such details may be departed from more or less without evading the spirit of my invention, and I do not propose to be limited to such details except as the same may be positively included in the claims hereto annexed or rendered necessary by the prior state of the art.

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

1. Aself-contained hydraulic hoistcomprising a casing having therein a pair of parallel communicating cylindrical bores, a hoistingpiston in one of said bores, a pump in the other of said bores, the cylinder of said pump being of considerably less volume than the said bore to provide an adequate reservoir therein for motive fluid, a check-valve between said bores, means for unseating the same, and trunnions on said casing.

2. In a hydraulic hoist, the combination of a cylinder, a motor-piston therein, a receptacle for motive fluid, a passage-way between said receptacle and said cylinder, a reciprocating cylinderwithin and of considerably less length than said receptacle, said cylinder adapted by its movement to close and establish communication between the receptacle. and the passage-way, a pump-piston in said cylinder,

and a stop intermediate the ends of the recep- (tiacle for limiting the movement of the cylin- 3. In a self-contained hydraulic hoist, the combination of a cylinder, a motor-piston therein, a fluid-receptacle adjacent said cylinder, a passage-way connecting said receptacle and said cylinder, a cylinder of considerably less length than said receptacle and of sufficiently smaller diameter than the inner diameter of said receptacle to provide an adequate reservoir for motive fluid, said cylinder reciprocating within said receptacle, and adapted to close communication between said passageway and said receptacle when at the end of a stroke, a piston within said last-mentioned cylinder and frictionally engaging the inner wall thereof, an operating-rod for said piston extending through said casing, means carried by said casing for engaging said rod to support the cylinder in a position to establish communication between the passage-way and the receptacle, a check-valve arranged to prevent the flow of fluid from the first-mentioned cylinder into the receptacle, and means for unseating said valve.

4:. In a hydraulic hoist, the combination of a cylinder, a motor-piston in said cylinder, a receptacle for motive fluid, a passage-way between said receptacle and said cylinder, a reciprocating cylinder within the receptacle adapted by its movement to establish and cut oif communication between the receptacle and the first-mentioned cylinder, a piston in said reciprocating cylinder, and a bushing adjacent each end of said cylinder.

5. In a hydraulic hoist, the combination of a cylinder, a motor-piston therein, a receptacle for motive fluid, a passage-way between said receptacle and said cylinder, a reciprocating cylinder in said receptacle, a piston in said cylinder, lugs projecting inwardly from said receptacle to form a guide for the cylinder, an inwardly-projecting boss above said lugs, the projection of the boss being no greater than that of the lugs, and a stop-pin fltted within said boss.

6. A self-contained hydraulic hoist consisting of a casing having therein a cylinder, a

piston in said cylinder, a receptacle for motive fluid'adjacent said cylinder, one end of said casing being hollow to form a part of the passage-way between said receptacle and said cylinder, a plate secured to said end of the casing and completing the passage-way, a reciprocating cylinder in said receptacle, said cylinder adapted to close and establish communication between the receptacle and the passage-way, a piston in said last-mentioned cylinder, said piston having a rod extending through the plate on the end of the casing, a bracket supported by said plate, a pin on the piston-rod adapted to engage said bracket to hold the cylinder in position to establish communication between the passage-way and receptacle, a check-valve between the passageway and the first-mentioned cylinder, and an operating-pin for unseating said valve, said pin being fitted in the plate at the end of the casing.

7. In a self-contained hydraulic hoist, the combination of a cylinder, a motor piston therein, a receptacle for motive fluid, a passage-way between said receptacle and said cylinder, a check-valve between said passageway and said cylinder, said valve having a slotted stem, a pin projecting into the slot in said stem, an operating-pin for unseating said check-valve, a reciprocating cylinder in the receptacle, said cylinder adapted to establish and to close communication between the rewith the bottom thereof, a pump in said 're-' ceptacle, a plug for the upper end of said receptacle, said plug having a valved passageway therethrough, and a concave receptacle surrounding said rod and the upper end of said plug and communicating with the passage-way therethrough.

In testimony whereof I afiix my signature in the presence of two witnesses.

URBAN HARVEY. Witnesses:

B. H. CAMDEN, WM. J. WHEELER.

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