US 4,597,263 AGranted

Pull type installation tool

AssigneeHuck Manufacturing Company

InventorRobert J. Corbett

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Abstract

An improved pneumatic-hydraulic actuated single action pull type installation tool for installing pull type fasteners is disclosed which includes a continuously pressurized fluid reservoir operative to maintain a minimum positive pressure on the hydraulic circuit during operation so as to protect the integrity of the hydraulic circuit during normal operating pressure fluctuations and to reduce the possibility of air being drawn into the hydraulic system during sudden pressure drops in the actuating pressure chamber which may occur at the time the pintail portion is separated from the fastener. Further, the reservoir provides a source of make up hydraulic fluid to replace any fluid which may be lost due to leakage. Suitable valves are provided to enable the reservoir to selectively communicate with both driving and return portions of the hydraulic circuit while still enabling selective pressurization thereof. Apparatus is also provided for enabling convenient and efficient refilling of the reservoir and to depressurize the reservoir such as for service. A high pressure relief valve is also provided in the circuit which is operative to vent the hydraulic system to atmosphere in the event of abnormal pressure build up.

Claims13

Dependent claims

In a pneumatic-hydraulically actuated pull type installation tool adapted for use in setting of pull type fasteners comprising a tool housing having a pneumatically actuated piston means, a substantially closed hydraulic circuit containing a hydraulic fluid including a driving portion and a return portion and associated sealing means, control valve means for selectively actuating said pneumatic piston means, said pneumatic piston means being connected to and operative to drive a first hydraulic piston means whereby hydraulic fluid pressure is applied through said hydraulic circuit to a second piston means to thereby reciprocably alternately move said second piston means through a driving stroke and a return stroke, reservoir means having an outlet connected in fluid communication with at least one of said driving portions and return portions of said hydraulic circuit, check valve means connected to said outlet from said reservoir and operative to prevent fluid flow from said driving and return portions of said hydraulic circuits to said reservoir, said reservoir means comprises an elongated reservoir chamber within said housing, a reservoir housing member secured within an opening provided in said housing and having a bore extending therethrough, a plunger movably extending into said chamber and including a portion projecting into said bore, said chamber containing a supply of hydraulic fluid and including means for continuously exerting a pressure on said hydraulic fluid whereby said hydraulic fluid is operative to maintain a minimum positive pressure on said one of said portions of said hydraulic circuit during both said driving stroke and said return stroke to thereby improve the efficiency of said sealing means and reduce leakage of said hydraulic fluid through said sealing means and pressure relief valve means disposed in fluid communication with said one of said driving and return portions of said hydraulic circuit, said pressure relief means being operative to vent said one portion to atmosphere in response to abnormally high pressure therein.

A pull type pneumatic hydraulic installation tool comprising:

a housing defining a pneumatic cylinder;
a pneumatically actuated piston means reciprocably disposed within said housing and dividing said cylinder into first and second portions;
control valve means for selectively applying compressed air alternatingly to said first and second portions;
a neck assembly having one end secured to said housing, said neck assembly including a master hydraulic cylinder having a master piston reciprocably disposed therein and dividing said master cylinder into a driving portion and a return portion;
means drivingly connecting said master piston to said pneumatically actuated piston;
a head assembly secured to the other end of said neck assembly and including a pulling cylinder having a hydraulically actuated pulling piston reciprocably disposed therein and operative to divide said pulling cylinder into a driving portion and a return portion;
driving passage means extending between said driving portion of said master cylinder and said driving portion of said pulling cylinder and operative to conduct pressurized fluid from said driving portion of said master cylinder to said driving portion of said pulling cylinder thereby enabling said master piston to drive said pulling piston through a driving stroke;
return passage means extending between said return portion of said master cylinder and said return portion of said pulling cylinder and operative to conduct pressurized fluid from said return portion of said master cylinder to said return portion of said pulling cylinder thereby enabling said master piston to drive said pulling piston through a return stroke;
reservoir means disposed within said head assembly, said reservoir means including a reservoir chamber having outlet passage means operative to place said chamber in fluid communication with said return portions of said master and pulling cylinders;
a plunger extending movably into said chamber;
biasing means engaging said plunger and being operative to continuously urge said plunger into said chamber whereby a pressure is exerted on a fluid within said chamber and said reservoir means is operative to maintain a continuous minimum positive fluid pressure on said return portions of said master and pulling cylinders;
check valve means disposed within said outlet passage means and operative to prevent fluid flow into said reservoir chamber;
first pressure relief valve means having an inlet connected in fluid communication with said return passage means and an outlet connected in fluid communication with said driving passage means,
said return portion of said master cylinder having a fluid capacity slightly greater than the maximum fluid capacity of said return portion of said pulling cylinder whereby movement of said master piston toward said one end is operative to produce a pressure differential between said return passage means and driving passage means sufficient to open said first pressure relief valve means to enable transfer of fluid to said driving passage means, said pressure relief valve being operative to maintain a minium positive fluid pressure on said driving portions of said master and pulling cylinders;
and
a second pressure relief valve having an inlet in fluid communication with said return passage means and being operative to vent said return passage means to atmosphere in response to abnormal pressure within said return passage means.

13 more elements

In a pull type installation tool having a substantially closed hydraulic operating circuit including a master cylinder containing a supply of hydraulic fluid and having a master piston reciprocably disposed therein, means for selectively moving said master piston between opposite ends of said master cylinder, a pulling cylinder having a pulling piston reciprocably disposed therein and first passage means for placing a first end portion of said master cylinder in fluid communication with a first end portion of said pulling cylinder and second passage means for placing a second end portion of said master cylinder in fluid communication with a second end portion of said pulling cylinder whereby movement of said master piston toward one of said first and second ends of said master cylinder will be operative to cause hydraulic fluid to flow under pressure from said one of said first and second ends of said master cylinder to a corresponding one of said first and second ends of said pulling cylinder thereby moving said pulling piston and also causing fluid flow from the other of said first and second ends of said pulling cylinder to the other of said first and second ends of said master cylinder whereby reciprocable movement of said master piston will effect a corresponding reciprocable movement of said pulling piston, pressure relief valve means operatively connected to enable fluid communication from said first to said second passage means in response to a predetermined pressure differential between said first and second passage means, reservoir means containing a supply of hydraulic fluid, reservoir passage means connecting said reservoir with said first passage means and check valve means disposed within said reservoir passage means and operative to prevent return of hydraulic fluid to said reservoir, said first end portion of said master cylinder having a fluid capacity slightly greater than the maximum fluid capacity of said one end of said pulling cylinder whereby movement of said master piston toward said one end is operative to produce a pressure differential at least equal to said predetermined pressure differential so as to open said pressure relief valve thereby enabling fluid to flow from said first passage means to said second passage means, said reservoir being operative to replenish fluid flowing from said first passage means to said second passage means.

Dependencies are inferred from the claim text.

Facts

Application: 06/320,193Filed 12 Nov 1981 · continuation
Priority: 18 Oct 1979
Granted: 1 Jul 1986
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

B21J 15/22
Drives for riveting machines; Transmission means therefor: operated by both hydraulic or liquid pressure and gas pressure
B21J 15/022
Riveting procedures: setting rivets by means of swaged-on locking collars, e.g. lockbolts
B21J 15/105
Riveting machines: portable riveters
B21J 15/326
Devices for inserting or holding rivets in position with or without feeding arrangements: broken-off mandrel collection