DE1254967B - Control device for a pneumatically operated hydraulic pump - Google Patents

Description

GERMAN WJTW ^ PATENT OFFICE DeutscheKl .: 59 a-10

EDITORIAL

Number: 1254 967

File number: B 626161 c / 59 a

j [254 967 filing date: May 25, 1961

Opening day: November 23, 1967

The invention relates to a control device for a pneumatically operated hydraulic Pump.

It is known (US Pat. No. 2,685,865) to use pumps of this type arranged on the pump housing To operate the foot pedal. There is usually one at one end of such a pump pneumatic chamber with reciprocating motor piston and a pneumatic valve block with the air inlets and outlets, the hydraulic chamber is located at the other end, while the Control device itself summarized in a block, the hydraulic control valves and one contains hydraulic working piston connected to the pneumatic motor piston. the Control device of such a known pump is improved according to the invention in that the legs of the pivot lever are hinged to the hydraulic valve block and that the two-armed trained pivot lever when depressing one arm the inlet valve of the pneumatic Chamber for the axially introduced compressed air opens and the outlet valve for the axially executed Hydraulic fluid controls.

This means that all controls can be operated by one and the same foot pedal, an additional one Manual operation, as in the case of the control device of the known pump, is not required. The external design The pump is slim, closed and protruding free, which is why the pump is used for many purposes is crucial.

The drawing shows, for example, a preferred embodiment schematically and partially in section the invention.

In the drawing, F i g. 1 is a perspective view of the pump,

Fig. 2 is a vertical longitudinal section through the pump with the pneumatic piston at the end of its forward stroke and at the beginning of its backward stroke. The hydraulic tank is in solid lines when filled and with dashed lines when empty,

F i g. 3 is a horizontal longitudinal section through the pump, with the pneumatic piston in its rearmost position is shown at the beginning of its forward stroke and

F i g. 4 shows a schematic representation of the position of the individual parts with respect to one another.

In the drawing, 10 is the pump housing arranged on the slide 11. At 12 he is on it attached operating lever called. The housing 10 encloses the valve block 14 on the right Control device for a pneumatically operated hydraulic pump

Applicant:

Applied Power Industries, Inc., Milwaukee, Wis. (V.St. A.)

Representative:

Dr. R. Bauer

and Dipl.-Ing. H. Hubbuch, patent attorneys,
Pforzheim, West 31

Claimed priority:

V. St. v. America May 26, 1960 (31919) -

closed pneumatic chamber 13 and the hydraulic chamber 15. The two chambers are separated by the valve block 16. The pneumatic chamber 13 is compressed air through the line 17 while the hydraulic fluid leaves the chamber 15 through the line 18. That Housing 10 is cylindrical, the chambers 13 and 15, the two valve blocks 14 and 16 and the connecting pieces the lines 17 and 18 lie one behind the other in the axial direction.

When the valve 26 is lifted, compressed air passes from the line 17 into the bore 22 of the valve block 14. The lifting takes place by pressing on the plunger 25 against the action of the spring 27. The Valve block 14 is also provided with an axial bore 35 into which bore 22 opens. She is after closed on the outside by a screw 36. The stem of a valve 37 is guided in the bore 35. The shaft has two recesses 38 and 39 and a collar 40 serving as a stop. Coaxial to the bore 35 is a recess 41 in the block 14, which has one or more bores 42 is in connection in the valve block 14, but closed off by a plate 43 after the chamber 13 is. The valve 37 fits into the recess 44 of the plate 43.

The shaft of the valve 37 is axially parallel between the recess 38 and the valve 37 Recess 45 which extends into the chamber 46. As a result, when is shifted to the right Valve stem connected to the bore 22 with the space 46, while the recess 41 of

709 689/266

Claims (4)

the space 46 is separated by the plate 43 and the valve 37 closing its recess 44. If, on the other hand, the valve stem is shifted to the left (FIG. 2), the recess 41 is connected to the space 46 through the recess 44, while the bore 22 is closed by the valve stem. In this way, the valve stem serves to alternately fill and empty the space 46. A piston 48, against which a spring 52 presses the head 51 of a pin piston 50, is displaceable in the pneumatic chamber 13. This serves to press the hydraulic fluid into the hydraulic line 18. The spring 52 is supported on the other hand on the valve block 16. The chamber 13 also has an outlet 54 in the cylinder wall, which is only released by the piston 48 in its extreme left position. In this position of the piston, the space 46 communicates via the channels 55, 56 with the recess 57, which is formed by the enlarged part of the bore 35 behind the collar 40 in the valve block 14 at the valve 37. When the valve 37 is in the position according to FIG. 3 is, i.e. H. the bore 22 opens into the recess 38, so compressed air enters the space 46 and pushes the piston 48 to the left. As soon as the piston 48 has reached its left end position, it opens the outlet 54. The compressed air, which thereby passes through the channels 55, 56 behind the collar 40, pushes the valve 37 to the left and the compressed air of the space 46 blows through the recess 44 and the bore 42. The piston 48 running back to the right, followed by the piston 50 by virtue of the spring 52, pushes the valve 37 back into the recess 44, whereby at the same time the bore 22 is connected again to the space 46 and the play can repeat itself. When the machine is operated in a dusty environment or under water, the outlet of the bore 42 in the valve block 14 is closed with a cap 106 made of flexible material. The cap 106 forms a flap valve which lets the compressed air out of the exhaust port of the bore 42, but does not let in atmospheric air, water or dust. The part of the chamber 13 which is close to the hydraulic valve block 16 is connected to the blow-out bore 42 via a channel 109 (FIG. 3). An opening 49 in the wall of the chamber 108 opens into the channel 109. The pump piston 50 moves in its cylinder 59 as a result of the interaction of the pneumatic piston 48 with the spring 52. This is the bore of a bushing 60 screwed into the hydraulic valve block 16. A ball 64 is mounted on the end face of the piston 50 and opens a channel 65 on the suction stroke. The hydraulic circuit in the valve block 16 comprises the channels 65 and 66, which lead to the hydraulic reservoir 67, and also the pressure fluid outlet 69, which can be closed by a one-way ball valve 68, 70 and leads to a pipe socket 71 axially penetrating the reservoir 67. In the container 67 there is a bag 73 which is fastened at one end by a ring 74 to the nozzle 71 and at the other to the wall of the chamber 15. Since the chamber 15 must be open to the outside air, 77, the bag 73 serves to protect the hydraulic fluid against the ingress of foreign bodies. The bag 73 also serves to utilize the last remainder of the hydraulic fluid. In order to prevent the hydraulic circuit from being disturbed by the collapsing bag 73, the wall of the valve block 16 can be provided with recesses 78 into which the hydraulic channels open. The valves are operated by pivoting the two-armed lever 12 back and forth. The lever 12 is articulated to the valve block 16 with screws 82, 83. The lever consists of one piece. It has a bridge part 86 which, against the action of the spring 87, can be pressed down onto the housing 10, namely the chamber 15, by hand or with the foot. The bridge part 86 connects two inclined legs 85. The axes of rotation with which the legs 85 of the pivot lever 12 are mounted in the valve block 16 are screws 82, 83. When screwed in, the screw 82 presses the valve ball 70 onto its seat against the action of the spring 90 68 and thereby closes and opens the hydraulic fluid valve 68, 70 described above when screwing in and unscrewing the screw . This pressure relief consists of a ball 98 which closes the channel 94, 95 leading from the connection 71 into the storage space 67 and can be lifted from its seat by the plunger 100 of the screw 83. Patent claims: 1. Control device for a pneumatically operated hydraulic pump which is operated by means of a foot lever arranged on the pump housing, at one end of which a pneumatic chamber with a reciprocating motor piston and a pneumatic valve block with the air inlets and outlets and at the other end a Hydraulic chamber are arranged, while the control device itself combined in a block contains hydraulic control valves and a hydraulic working piston which is connected to the pneumatically operated motor piston Ver ⁱ , characterized in that the legs (85) of the pivot lever (12) on the hydraulic valve block (16) are articulated and that the two-armed (84, 86) designed pivot lever when depressing one arm (84) opens the inlet valve (26) of the pneumatic chamber for the axially introduced compressed air and the outlet valve (68,70) for the axially executed Hydraulic fluid controls 2. Pump according to claim 1, characterized in that the compressed air inlet valve (26) and the pressure fluid outlet valve (68, 70) are each operated Weil in opposite pivoting movements of the rocker arm (12). 3. Pump according to claim 1 or 2, characterized in that the hydraulic fluid valve (68.70) is actuated by the rotation of its legs (85) about one of its axes of rotation (82). 4. Pump according to one of the preceding claims, characterized in that the axis of rotation (83) of the other leg (85) of the rocker arm (12) controls a hydraulic pressure relief valve (98).