US 3,937,071 AGranted

Fatigue test apparatus

AssigneeThe United States of America as represented by the Secretary of the Army

InventorsStanley A. Slota, Raymond F. Wegman

Life of this patent

Estimating the term…

Loading patent…

Abstract

Four tensional test stations are mounted on a rectangular support frame m up of four channels. Each test station comprises an air cylinder attached to the frame and having a tensioning piston connected to a first specimen holder, a second specimen holder attached to the frame, a solenoid valve connected to each air cylinder, and a test terminate switch closed by the piston and first specimen holder. Current pulses are applied intermittently to each of the four stations by a motor-driven timer switch comprising a fixed contact plate, four spring contacts and a drive shaft having four shaped insulated cams engageable with the four spring contacts to move them into contact with the contact plate in a desired sequence. An electrical elapsed-time indicator is connected in parallel with the solenoid valve and timer switch contacts and in series with the test terminate switch, in each station. Compressed air is supplied from a source through a pressure regulator and a manifold to the inlets of the four solenoid valves. The support frame is partly enclosed by a box cover.

Claims6

Dependent claims

Fatigue testing apparatus comprising:

a rigid support frame, a plurality of test stations mounted on said support frame;
a source of air pressure and a manifold for conducting air from said source to said stations;
a voltage source;
and a program timer switch comprising a plurality of switch contacts, one for each of said test stations, and means for connecting one side of said voltage source to each of said contacts in a predetermined sequence;
each of said test stations including:
first and second spaced specimen holders adapted to be attached to opposite ends of a specimen to be tested, said first specimen holder being attached to said support frame;
an air cylinder attached to said support frame and having a piston to which said second specimen holder is attached;
a solenoid valve having an air inlet connected to said manifold, an air outlet connected to said air cylinder, and two electrical terminals;
a test terminate switch having two electrical terminals and an actuating lever engageable with an actuating member carried by said piston and second specimen holder and adapted to open the switch when the specimen fails, one of said terminal being connected to the other side of said voltage source, and the other terminal being connected to one terminal of said solenoid valve;
and
means connecting the other terminal of said solenoid valve to one of said plurality of switch contacts of said timer switch, to complete the circuit from said voltage source to said solenoid valve;
whereby the failure of one specimen during the testing of a plurality of specimens interrupts the voltage circuit of its station only.

9 more elements

Dependencies are inferred from the claim text.