# US 4,398,531 A · Percussor

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- Number: US 4,398,531 A
- Document ID: US4398531A
- Status: Granted
- Kind: A
- Application number: 06/223,354
- Filed: 1981-01-08
- Granted: 1983-08-16
- Earliest claimed: 1979-06-21
- Assignees: Hudson Oxygen Therapy Sales Company
- Inventors: Harold R. Havstad
- Web page: https://patentgrep.com/patent/US4398531A

## CPC

- A61H 23/04: with hydraulic or pneumatic drive {(hydraulic or Pneumatic massages, A61H9/00; underwater massages, A61H33/00)}
- A61H: PHYSICAL THERAPY APPARATUS, e.g. DEVICES FOR LOCATING OR STIMULATING REFLEX POINTS IN THE BODY; ARTIFICIAL RESPIRATION; MASSAGE; BATHING DEVICES FOR SPECIAL THERAPEUTIC OR HYGIENIC PURPOSES OR SPECIFIC PARTS OF THE BODY (electrotherapy, magnetotherapy, radiation therapy or ultrasound therapy A61N)

## Abstract

An improved percussor assembly having a reciprocating percussion member for directing reciprocating motion to a user including a valve responsive to movement of the percussion member for temporarily and alternately interrupting the flow of gas in the percussor in response to the alternate movement of the reciprocating percussion member.

## Claims

### Claim 1

A percussor comprising:
a reciprocating assembly comprising a reciprocating plate and an applicator cooperating therewith for directing reciprocating motion from said plate to a user,
a gas outlet passageway, a gas pressure chamber and releasable gas sealing means for forming a gas-tight seal therebetween,
a gas inlet passageway communicating with said gas pressure chamber for introducing gas thereto at a pressure sufficient to release said gas-tight seal causing movement of said reciprocating assembly,
valve means for temporarily interrupting the flow of gas from said gas inlet passageway to said gas pressure chamber when said reciprocating assembly is moved, and
a valve actuation means rigidly secured to said reciprocating assembly and simultaneously reciprocating therewith for alternately opening and closing said valve means.

### Claim 2 (depends on 1)

The assembly of claim 1 wherein said valve means alternately opens and closes said communication between said gas inlet passageway and said gas pressure chamber.

### Claim 3 (depends on 2)

The assembly of claim 2 wherein said reciprocating assembly is biased and urged to a first position and said gas sealing means forms said gas-tight seal, said reciprocating assembly moving to a second position when said gas-tight seal is released, and wherein said valve actuation means includes a valve actuation member for closing said valve means as said reciprocating assembly is moved from said first position to said second position, and for opening said valve means as said reciprocating assembly is moved from said second position to said first position.

### Claim 4 (depends on 3)

The assembly of claim 3 wherein said valve means includes a ball and biasing means cooperating therewith for urging said ball to close said communication between said gas inlet passageway and said gas pressure chamber.