Scalpel

• US 5,211,652 A
• Filed: 10/03/1991
• Issued: 05/18/1993
• Est. Priority Date: 10/03/1991
• Status: Expired due to Fees

• Current Assignee: Bruce Derbyshire
• Original Assignee: Bruce Derbyshire
• Inventors: Derbyshire, Bruce
• Primary Examiner(s): Burr, Edgar S.
• Assistant Examiner(s): Nguyen, Anthony H.
• Application Number:
  US07/771,136
• Time in Patent Office: 593 Days
• Field of Search: 606/182, 606/181, 606/167, 606/171, 606/172, 606/185, 606/205, 606/206
• US Class Current: 606/182
• CPC Class Codes: A61B 17/3213 with detachable blades
• CPC Class Codes: A61B 2017/00539 hydraulically
• CPC Class Codes: A61B 2017/32113 with extendable or retractable guard or blade

Abstract

A retractable blade scalpel comprises a knife blade, a flexible envelope, and an elongated housing forming a blade containment area. When pressure is applied to the flexible envelope the knife blade is longitudinally displaced to a protruding usage position. The knife blade remains outside the housing as long as pressure is applied to the flexible envelope.

Claims

1. A retractable blade cutting device comprising;

an elongated housing forming a blade containment area and an envelope containment area;

a blade reciprocally movable between a withdrawn position within said blade containment area and an extended position protruding exteriorly of said housing;

biasing means for exerting a biasing force urging said blade into said withdrawn position;

a flexible closed envelope partially enclosed within said envelope containment area, said envelope containing a fluid and having at least one actuator surface accessible from the exterior of said housing; and

means to position said blade in the extended position only upon application and maintenance of pressure to said envelope, said means including

a piston associated with said blade and engageable by said flexible envelope such that when pressure is applied to said actuator surface, said piston is actuated by said envelope, thereby overcoming the force exerted by said biasing means and causing said blade to shift from said withdrawn position to said extended position, and upon release of said pressure said biasing means returning said blade to said withdrawn position.

2. A device as claimed in claim 1, wherein said fluid within said flexible envelope is a liquid.

3. A device as claimed in claim 1, wherein said flexible envelope includes a pleated portion which extends when pressure is applied to said actuator surface.

7. A device as claimed in claim 1, wherein said biasing means further includes resilient means for returning said blade to said blade containment area when said pressure is relieved.

4. A retractable blade cutting device comprising:

an elongated housing forming a handle and internally defining a blade containment area;

a blade assembly including a blade mounted for reciprocal movement between a retracted position containing within said blade containment area, and an extended position protruding from said blade containment area exteriorly of said housing;

biasing means for exerting a biasing force urging said blade into said blade containment area; and

a flexible closed envelope containing a fluid and arranged within said housing adjacent to said blade assembly, said envelope having an actuator surface accessible from the exterior of said housing, and means to position said blade in the extended position only upon application and maintenance of pressure to said envelope to overcome the force exerted by said biasing means and urge said blade into said extended position, release of said pressure resulting in said biasing means returning said blade to said blade containment area.

5. A device as claimed in claim 4, wherein said fluid within said flexible envelope is a liquid.

6. A device as claimed in claim 4, wherein said flexible envelope includes a pleated portion which extends when pressure is applied to said actuator surface.

8. A device as claimed in claim 4, wherein said biasing means further comprises a resilient means for returning said blade to said retracted position when said pressure is relieved.