US3296796A

US3296796A - Hydraulically operated tools

Info

Publication number: US3296796A
Application number: US448914A
Authority: US
Inventors: Hadari Moshe
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-04-08
Filing date: 1965-04-06
Publication date: 1967-01-10
Anticipated expiration: 1984-01-10
Also published as: DE1298054B; GB1060205A

Description

M. HADARI Jan. 10, 196-7 HYDRAULICALLY OPERATED TOOLS 3 Sheets-Sheet 1 Filed April 6, 1965 lllllllllllllll. l

MKM Attorney;

Jan. 10, 1967 M. HADARI HYDRAULICALLY OPERATED TOOLS 5 Sheets-Sheet 2 Filed April 6, 1965 Inventor Mia/var Attorn: JS

Jan. 10, 1967 HADAR' 3,296,796

HYDRAULICALLY OPERATED TOOLS Filed April 6, 1965 a Sheets-Sheet s Inventor Ho /15 #Apfifl/ B 01%, m %:O W

rneys United States Patent M 3,296,796 HYDRAUUCALLY OPERATED TOGLS Moshe Hatlari, 44 Haganah St., Givat Rambam, Israel Filed Apr. 6, 1965, Ser. No. 448,914 Claims priority, application Israel, Apr. 8, 1964,

1 4 Claims. (Cl. 611-52) This invention relates to hydraulically operated tools such as vices, clamps, presses or the like.

It is an object of the present invention to provide a simple hydraulically operated tool which is capable of ready manual operation and which can be constructed in a readily portable and self-contained form.

According to the present invention there is provided a hydraulically operated tool having a pump unit comprising first and second juxtaposed pump cylinders of differing diameters, a main cylinder integral with said pump unit, a duct system effecting communication between the pump unit and the main cylinder, a hydraulic fluid reservoir,'a first set of unidirectional valves permitting flow of the hydraulic fluid into the pump unit from the reservoir, a second set of unidirectional valves permitting flow of the hydraulic fluid from the pump unit to the second component cylinder via the duct system, a manually controllable control valve assembly arranged to direct the fluid into either end of the main cylinder and from either end of the main cylinder back into the reservoir, first and second pistons respectively slidable in the pump cylinders, manually operable, pivotally mounted rocker arms adapted respectively to bear on said first and second pistons, means for displacing said rocker arms against a restoring force so as to displace said first or second piston, a main piston slidable in the main cylinder under the influence of the hydraulic fluid, a displaceable tool component, a rod secured to said main piston and slidably articulated with respect to said tool component, a fixed abutment constituting a limit to the relative sliding motion of said tool component and rod and spring biasing means for biasing said tool component and rod together.

One embodiment of the invention in the form of a hydraulic vice will now be described by way of example and with reference to the accompanying drawings in which,

FIG. 1 is a longitudinal sectional view of the vice taken along the line I-I of the view shown in FIG. 3,

FIG. 2 is a longitudinal sectional view of the vice taken along the line IIII of the view shown in FIG. 3,

FIG. 3 is an end elevation of the vice, taken along line III-III of FIG. 1,

FIG. 4 is a cross-sectional view of the control valve mechanism,

FIG. 5 is a cross-sectional view of the cylinder cover, and

FIG. 6 is a schematic representation of the oil flow in the hydraulic device.

As seen in the drawings the vice includes a relatively fixed jaw 1 and a relatively movable jaw 2. The fixed jaw 1 is formed integrally with a box-like casing 3 whilst the relatively movable jaw 2 is formed integrally with an elongated carrying arm 4. Located in the casing 3 and bolted thereto is a pump body 5 in which are formed side by side a pair of pump cylinders 6 and 7 of equal length, the cylinder 6 being of greater cross-sectional area than the cylinder 7. Slidable in the cylinders 6 and 7 are a pair of pistons 8 and 9 having piston rods 10 and 11. Formed in the upper surface of the pump body 5 and respectively aligned with the cylinders 6 and 7 are a pair of elongated slots 12 and 13 into which respectively project the

striking ends

14 and 15 of a pair of

rocker arms

16 and 17 which are respectively pivoted on 3,Z%,7% Patented Jan. 1%, 11367 a pivotal axle 18 which is fixed with respect to the casing 3. Outwardly extending arms 19 and 20 of the rocker arms are respectively provided with actuating

cables

21 and 22 secured to actuating pedals (not shown). The upper ends of the

arms

16 and 17 are biased in a clockwise direction by means of. tension springs 23 and 24 which are respectively secured at one pair of ends to the ends of the

rocker arms

16 and 17, and at the other pair of ends to a fixed position with respect to the casing 33. Pivoting of the rocker arms in the clockwise direction is limited by the abutting of the outwardly extending limbs 19 and 20 against a fixed abutment pin 25.

The outlets of the cylinders 6 and 7 communicate with a valve box 26 as seen schematically in FIG. 6 of the drawings. The valve box 26 includes a pair of

unidirectional valves

27 and 28 which respectively control communication between the cylinders 6 and 7, and an oil reservoir 29 and a pair of

outlet valves

30 and 31 which communicate respectively with the cylinders 6 and 7 via the

valves

27 and 28.

Thus, as can be seen in FIG. 6 of the drawings, a compression stroke of the piston 8 results in hydraulic fluid being pressed out of the outlet of the cylinder 6 through the unidirectional valve 30 into the outlet duct 32 whilst a suction stroke of the cylinder 6 results in hydraulic fluid being sucked from the reservoir 29 through the suction duct 33 and valve 27. Similarly the operation of the cylinder 7 takes place via the

valves

28 and 31.

The pump outlet duct 32 is coupled via a control valve arrangement 34 and via

ducts

35 and 36 with either end of a main cylinder 37 in which is slidable a main piston 38 having a piston rod 74, the main cylinder 37 being bolted to the casing 3.

As seen schematically in FIG. 6 of the drawings the control valve arrangement 34 comprises four

separate component valves

41, 42, 43 and 44 which are so coupled that the outlet of the valve 41 is connected to the inlet of the valve 44 whilst the outlet of the valve 42 is connected to the inlet of the Valve 43. As will be explained below, the actuating mechanism of the valves is so arranged that as the

valves

42 and 44 are opened the

valves

41 and 43 are simultaneously closed and vice versa. Thus upon opening the

valves

42 and 44 and closing the

valves

41 and 43 oil under pressure flows from the conduit 32 through the open valve 42 into the conduit 35 and into the left-hand end of the cylinder 37 so as to push the piston 38 to the right and in consequence to open the vice. At the same time oil is pushed out of the right-hand end of the cylinder through the conduit 36 and via the opened valve 44 into the tank reservoir 29.

On the other hand when the valves 41 and 4-3 are opened whilst the

valves

42 and 44 are closed oil is passed under pressure through the conduit 32 into the conduit 36 and so into the right-hand end of the cylinder displacing the piston to the left and resulting in the closing of the vice whilst oil is pressed out of the cylinder 37 by the piston 33 through the conduit 35 and through the open valve 43 into the reservoir tank 29.

The construction of the control valve assembly 34 will now be described with reference to FIG. 4 of the drawings. As seen in this figure the valve arrangement 34 comprises a valve block 45 in which are formed four cylindrical valve bores (only two being shown in FIG. 4 of the drawings) in each bore being located a valve body having a conical nose which bears under the influence of a biasing spring against valve seating formed by a shoulder of the valve bore. The particular valves shown in FIG. 4 of the drawings correspond to the

valves

41 and 42 schematically in FIG. 6. The valve arrangement shown in FIG. 4 has at its side three outlets (only two being visible) the outlet 51 being connected via conduit 32 to the pumps 6 and 7 via the valve 26, the outlet 52 being connected via the conduit 53 to the tank reservoir 29 and the remaining outlet (not visible) being connected via the conduit 35 to the left-hand end of the cylinder 37. The remaining outlet of the valve mechanism is connected via an outlet screw 54 and the conduit 36 to the righthand end of the cylinder.

The actuating mechanism of the component valves will now be described.

The heads of the

valve bodies

42 and 44 and 41 and 43 are coupled by respective coupling bars 55 and 56. A pair of actuating screws 57 and 58 which are screwed through a supporting bar 59 bear respectively on the bars 55 and 56. The screw 57 is coupled to a toothed wheel 59 which engages in a second toothed wheel 60 coupled to the screw 58. The toothed wheel 59 is turnable by means of a turning handle 62 coupled thereto. Rotation of the handle 62 in a clockwise sense results in rotation of the toothed wheel 59 in a clockwise sense and displacement of the screw 57 so as to press the valve body on its seating against the biasing effect of the spring. At the same time however the clockwise motion of the toothed wheel 59 is accompanied by an anticlockwise motion of the toothed wheel 60 and a displacement of the screw 58 so as to release the valve body from bearing on its seating. In this way therefore rotation of the handle 62 in one sense results in the closing of the

valves

42 and 44 and opening of the

valves

41 and 43, whilst rotation of the handle 62 in the opposite sense results in the opening of the

valves

42 and 44 and closing of the

valves

41 and 43.

The mode of coupling of the piston rod 74 to the movable jaw 2 will now be described.

As seen in the drawings (FIG. 1) the piston rod 74 passes slidably through an aperture formed in a downwardly extending flange 4a of the carrier arm 4. The piston rod 74 is provided with a flanged shoulder 61 secured thereto and which bears on the rim of the aperture formed in the flange 4a. Surrounding the piston rod 74 and enclosed in a casing 62a secured to the flange 4a is a spring battery 63 which bears at one end on the flange 4a and at the other end on a nut 64 coupled to the piston rod 74.

The operation of the hydraulic device will now be described.

In the position shown in the drawings the vice jaws 1 and 2 have been brought together and the operation of the hydraulic system in opening the jaws 1 and 2 will be described. In-order to effect opening of the jaws it must be ensured that hydraulic fluid under pressure is applied to the right-hand face of the piston 38. For this purpose handle 62 is rotated in a sense such as to open the

valves

41 and 43 and close the

valves

42 and 44. With the valve assembly 34 in this position the pedal secured to the cable 21 is depressed as a result of which the rocker arm 16 is pivoted in an anticlockwise direction against the biasing force of the spring 23 so as to press the piston 8 forward thereby forcing hydraulic fluid under pressure through the unidirectional valve 30 into the conduit 32. The resulting movement of the piston rod 74 results in the shoulder 61 bearing on the flange 4a of the carrier arm of the jaw 2 and the jaw 2 moving outwardly away from the jaw 1. Continued pedalling results in the continued motion of the piston 38 and the opening of the vice, this motion continuing until the piston 38 arrives at the left-hand end of the cylinder 37.

When it is desired to close the jaws, that is to bring them together, the handle 62 is rotated in an opposite sense thereby opening the

valves

42 and 44 and closing the

valves

41 and 43. If now the pedal associated with the cable 21 is depressed continuously hydraulic fluid is forced through the conduit 32 into the conduit 35, i.e. into the left-hand end of the cylinder thereby pushing the piston to the right. The movement of the piston under the influence of fluid forced out of the larger of the two cylinders 6 is not capable of fine control. When the movable jaw 2 has reached approximately the required position, further fine clamping adjustment of the jaw 2 can be obtained by pedalling movement on the pedal associated with the cable 22 as a result of which hydraulic fluid is pumped out of the smaller cylinder 7 and through the unidirectional valve 31.

It will be seen that movement of the movable jaw 2 towards the fixed jaw 1 results from the spring battery 63 bearing on the adjacent end of the carrier arm of the movable jaw 2. When the movable jaw 2 has been moved into such position that an object is clamped between the two jaws further pumping by the piston 6 or 7 results in compression of the spring battery 63. Should a slight hydraulic leak develop whilst the jaws are in a clamping position this leak will not result in the movement apart of the two jaws and consequent release of the object seeing that the jaws will continue to be pressed together by the spring battery in addition to being hydraulically pressed.

I claim:

1. A hydraulically operated tool having a pump unit comprising first and second juxtaposed pump cylinders of different diameters, a main cylinder integral with said pump unit, a duct system effecting communication between the pump unit and the main cylinder, a hydraulic fluid reservoir, a first set of unidirectional valves permitting flow of the hydraulic fluid into the pump unit from the reservoir, a second set of unidirectional valves permitting flow of the hydraulic fluid from the pump unit to the main cylinder via the duct system, a manually controllable control valve assembly arranged to direct the fluid into either end of the main cylinder and from either end of the main cylinder back into the reservoir, first and second pistons respectively slidable in the pump cylinders, manually operable, pivotally mounted rocker arms adapted respectively to bear on said first and second pistons, means for displacing said rocker arms against a restoring force so as to displace said first or second piston, a main piston slidable in the main cylinder under the influence of the hydraulic fluid, a displaceable tool component, a rod secured to said main piston and slidably articulated with respect to said tool component, a fixed abutment constituting a limit to the relative sliding motion of said tool component and rod and spring biasing means for biasing said tool component and rod together.

2. A hydraulically operated tool according to claim 1, wherein said control valve assembly comprises two pairs of valves, each valve having a control rod spring biased into opening the valve, the control rod of each pair being coupled together by a single coupling bar, a pair of screw members respectively arranged to abut said coupling bars and respectively associated with a pair of interengaging toothed wheels and means for rotating one of said wheels so as to open one pair of valves and close the other pair of valves.

3. A hydraulically operated tool according to claim 1 wherein said rocker arms are respectively coupled by means of cables to foot pedals.

4. A hydraulically operated vice according to claim 1 wherein said displaceable tool component is constituted by a movable jaw of a vice, the fixed jaw thereof being secured to a casing of the tool which encloses and is secured to the pump unit and main cylinder and in which is disposed the hydraulic fluid reservoir.

References Cited by the Examiner UNITED STATES PATENTS EDGAR W. GEOGHEGAN, Primary Examiner.

Claims

1. A HYDRAULICALLY OPERATED TOOL HAVING A PUMP UNIT COMPRISING FIRST AND SECOND JUXTAPOSED PUMP CYLINDERS OF DIFFERENT DIAMETERS, A MAIN CYLINDER INTEGRAL WITH SAID PUMP UNIT, A DUCT SYSTEM EFFECTING COMMUNICATION BETWEEN THE PUMP UNIT AND THE MAIN CYLINDER, A HDRAULIC FLUID RESERVOIR, A FIRST SET OF UNIDIRECTIONAL VALVES PERMITTING FLOW OF THE HYDRAULIC FLUID FROM THE PUMP UNIT TO THE THE RESERVOIR, A SECOND SET OF UNIDIRECTIONAL VALVES PERMITTING FLOW OF THE HYDRAULIC FLUID FROM THE PUMP UNIT TO THE MAIN CYLINDER VIA THE DUCT SYSTEM, A MANUALLY CONTROLLABLE CONTROL VALVE ASSEMBLY ARRANGED TO DIRECT THE FLUID INTO EITHER END OF THE MAIN CYLINDER AND FROM EITHER END OF THE MAIN CYLINDER BACK INTO THE RESERVOIR, FIRST AND SECOND PISTONS RESPECTIVELY SLIDABLE IN THE PUMP CYLINDERS, MANUALLY OPERABLE, PIVOTALLY MOUNTED ROCKER ARMS ADAPTED RESPECTIVELY TO BEAR ON SAID FIRST AND SECOND PISTONS, MEANS FOR DISPLACING SAID ROCKER ARMS AGAINST A RESTORING FORCE SO AS TO DISPLACE SAID FIRST OR SECOND PISTON, A MAIN PISTON SLIDABLE IN THE MAIN CYLINDER UNDER THE INFLUENCE OF THE HYDRAULIC FLUID, A DISPLACEABLE TOOL COMPONENT, A ROD SECURED TO SAID MAIN PISTON AND SLIDABLY ARTICULATED WITH RESPECT TO SAID TOOL COMPONENT, A FIXED ABUTMENT CONSTITUTING A LIMIT TO THE RELATIVE SLIDING MOTION OF SAID TOOL COMPONENT AND ROD AND SPRING BIASING MEANS FOR BIASING SAID TOOL COMPONENT AND ROD TOGETHER.