US2791028A - Hydraulically operated hand tools - Google Patents

Description

May 7, 1957 P. BlDlN HYDRBULICALLY OPERATED HAND TOOLS Filed May 10, 1956 INVENTOR PETER '8! DIN ATTORNEY HYDRAULICALLY OPERATED HAND TOOLS Peter Bidin, Vancouver, British Columbia, Canada Application May 10, 1956, Serial No. 584,064

7 Claims. (Cl. 30-180) My invention relates to improvements in hydraulically operated hand tools.

The objects of the invention are to provide a two handled hydraulically operated tool whereby one of the handles serves the dual purpose of coacting with the other to cause a pair of jaws, cutters or other devices to close or open, and also to control a relief valve whereby the fluid used in exerting a closing movement on the cutters may be returned to reserve and the cutters may return to open or normal position.

A further object is to locate the manually operable cylinder in alignment with the cutter operating cylinder.

A still further object is to reduce the weight and diameter of the tool by changing the type and disposition of the fluid reserve chamber.

A still further object is to provide for the operating connection between a handle and the pressure pump to be between the operating handles, so as to protect the pump plunger and its glands from damage during the operation of the tool.

Referring to the accompanying drawings:

Figure 1 is a vertical elevation of the invention shown part in section.

Figure 2 is an enlarged section taken on the line 22 of Figure 1.

Figure 3 is an enlarged section taken on the line 3-3 of Figure 2.

Figure 4 is a plan view of the base of the ram cylinder.

Figure 5 is a transverse sectional view taken on the line 55 of Figure 4.

In the drawings like characters of reference indicate corresponding parts in each figure.

The numeral 1 indicates a cylindrical body casting having a skirt 2 which supports a vertical sleeve 3 on one side and a downwardly projecting fork 5 on the opposite side. A base 6 is fitted into the underside of the body casting and is held in place vertically by a split ring 8, which base forms the end of the ram cylinder 9, see Figures 2 and 3, and also forms a chamber for the valves to be hereinafter referred to.

The cylindrical body 1 is concentrically spaced from the ram cylinder 9 to define a space 11 in which a fluid reservoir 12 is carried. The fluid reservoir is a distendable bag in the form of a sleeve having its upper end secured by a suitably sealed bond to the periphery of the ram cylinder and its lower end to the base 6 as shown in Figures 2 and 3.

Fitted in the base 6, see Figure 3, is a hydraulic pump cylinder 14, see Figures 1, 2 and 3, having a plunger 15 which is hingedly connected to a bell crank 16 fitted on the inner end of an operating handle 17. A handle 18 is reduced at its upper end to form an eccentric 19 and is provided with a stem 20 which extends through the vertical sleeve 3 and is provided with a locking ring 21 to prevent said handle from being removed downwardly. A pin 24 is fitted in the side of the handle 18 which is adapted to engage a stop 25 to limit the rotation of said handle 18.

2,791,028 Patented May 7, 1957 Extending transversely across the base 6, see Figure 3, is a passageway 27 divided into chambers 28, 29 and 30. The chamber 28 is divided from the chamber 29 by a spring loaded valve 32 and is in communication with the ram cylinder 9 through a duct 33. The chamber 29 is provided with a ball valve 34 which closes oil the chamber 30 therefrom and the chamber 30 communicates with the fluid reservoir 12 through a duct 35. The hydraulic pump cylinder 14 is in communication through a duct 36 with the centre chamber 29.

Fitted in the chamber 30 and in contact with the eccentric 19 of the handlelS is a valve stem or push rod 37 which extends substantially into contact with the ball valve 34 to push it off its seat. A distance piece 38 is interposed between the ball valve 34 and the spring loaded valve 32, so that when the handle 18 is turned to unseat the valve 34, the valve 32 is opened also to allow the fluid to flow from the fluid reservoir 12 and from the ram cylinder 9 back to the hydraulic pump cylinder 14.

The body casting is provided with a tubular extension 40 having longitudinal slots 41 in which a crosshead 42 is guided. A spring 43 is enclosed in the extension and bears downwardly upon the crosshead to return the ram plunger 44 into its cylinder 9. At the outer end of the tubular extension a pair of cutters, or other tools 45, are hingedly mounted, which cutters have levers 46 which are link connected as at 48 to the crosshead 42 so that as the ram plunger 44 is outwardly urged the cutters will move towards each other in the usual way.

Extending horizontally from the chamber 29 is a duct 50, see Figure 2, which is fitted with a heavily spring loaded valve 51. The duct 50 communicates through a vertical duct 52 with the fluid reservoir 12.

A filler duct 54, see Figures 4 and 5, is formed in the base 2 and is fitted with a screw plug 55. The duct 54 communicates with the fluid reservoir 12, so that on removal of the plug 55 fluid may be entered into the fluid reservoir to keep the fluid spaces suitably filled.

In operation, assuming that a rod is to be cut, the cutters will be placed on opposite sides of said rod and the handles firmly gripped by the operator. The handle 18 will be held with the pin 24 against its stop 25, so that the valves 32 and 34 will be normally closed. When the handle 17 is swung towards the handle 18, the plunger 15 will cause fluid from its cylinder to flow into the chamber 29, open the spring loaded ball valve '32 and deliver fluid through the duct 33 to the ram cylinder 9 to extend its plunger 44 and move the cutters 4-5 to become embedded in the work to be cut. As the handle 17 is swung away from the handle 18 the retraction of the plunger '15 will draw fluid from the reservoir 12 past the valve 34 to the pump cylinder to be subsequently delivered to the ram cylinder. lf undue pressure is applied to the plunger 44 of the ram cylinder, the heavily spring loaded valve 51 will be pushed off its seat and the fluid in the pump cylinder 14 will be diverted into the reservoir 12, thus forming a safety device for the tool with out losing any of the fluid charge.

When a cut has been made, it suitices to turn the handle 18 to cause the eccentric 19 to force the valves 32 and 34 off their seats when the fluid from the ram cylinder 9 will be forced by the reaction of the spring 43 bearing upon the crosshead and will flow into the pump cylinder 14 and back to the reservoir 12 as needed.

What I claim as my invention is:

1. In a portable hydraulic ram type tool having work engaging elements, a pair of handles lying in a single plane, a ram feed pump, and a closed fluid system in cluding the ram cylinder, the feed pump and a fluid reservoir, said feed pump being disposed with its plunger 'ice disposed between and in .the plane of the handles and substantially parallel to the axes of said handles.

2. -In a portable hydraulic ram type tool having work engaging elements, a pair of handles, a ram feed pump anda closed fluid system including the ram cylinder, the feed pump and a fluid reservoir, valve means for feeding fluid from the reservoir and a second valve means operable in response to the twisting of one of said handles for opening said second valve means to return fluid from the ram to thereservoir.

3. In a portable hydraulic ram type tool as claimed in-claim -2, wherein the second valve means is opened to return fluid from the feed pump to the reservoir.

4. In a portable hydraulic ram, type tool as claimed in claim 2, wherein a spring loaded normally closed valve is interposed'between the feed pump and the reservoir whereby said valve will open in response to abnormal pressure being developed in the feed pump tobypass fluid back to-the reservoir.

5. In a portable hydraulic ram type tool having work engaging clements, a base supporting a ram cylinder and the work engaging elements, a pair of handles carried by the base, a fluid feed pump parallel to and -lying in the plane of the handles, a fluid reservoir surrounding the ram cylinder, one of said handles being adapted to operate the feed pump and the other of said handles being adapted to establish fluid flow from the ram cylinder to the reservoir.

6. In a portable hydraulic ram type tool having .work

engaging elements, .a base supporting a ram cylinder and the work engaging elements, a pair of handles carried by the base, a fluid feed pump parallel to and lying in the plane of the handles, a fluid reservoir surrounding the ram cylinder, one of said handles being adapted to operate the feed pump, the second of said handles being mounted in fixed relation to the base and the ram cylinder, said reservoir being distendable and surrounding said rarn cylinder.

'7. In a portable hydraulic ram type tool having work engaging elements, a pair of handles, a ram feed pump and a closed fluid system including the ram cylinder, the feed pump and a fluid reservoir, valve means for feeding fluid from the reservoir and a second valve means operable in response to the twisting of one of said handles for opening said second valve means to return fluid from the ram to the reservoir, said second valve means being opened to return fluid from the feed pump to the reservoir, and a spring loaded normally closed valve interposed between the feed pump and the reservoir whereby said valve will open in response to abnormal pressure being developed in the feed pump to by-pass fluid back to the reservoir.

No references cited.

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