Safety trocar instrument having a retractable trocar actuated by relief of pressure on the trocar point
First Claim
1. A safety trocar instrument for piercing the wall of an anatomical cavity to provide communication with the inside of the cavity, said trocar instrument comprising:
- (a) a tubular cannula;
(b) an elongate trocar, having a sharp piercing point, mounted for axial reciprocal movement within said cannula between a withdrawn rest position in which said point is received within and shielded by the distal end of said cannula, a fully extended position in which said point is exposed beyond the distal end of said cannula, and an intermediate position retracted toward the rest position from the fully extended position in which said point is also exposed beyond the distal end of said cannula;
(c) means for biasing said trocar to its withdrawn position;
(d) latch means for latching said trocar, in opposition to said biasing means, for reciprocal movement between the fully extended position and the intermediate position; and
(e) trip means coupling said trocar to said latch means when said trocar moves from the fully extended position to the intermediate position, and tripping said latch means when said trocar returns toward said fully extended position to unlatch said trocar and thereby permit said trocar to be moved to the withdrawn rest position by said biasing means.
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0 Petitions
Accused Products
Abstract
A safety trocar instrument, for piercing the wall of an anatomical cavity to provide communication with the inside of the cavity, includes a tubular cannula and an elongate trocar having a sharp piercing point. The trocar is mounted for axial reciprocal movement within the cannula between a withdrawn rest position, in which the point is received within and shielded by the distal end of the cannula, a fully extended position in which the point is exposed beyond the distal end of the cannula, and an intermediate retracted position in which the point also is exposed beyond the distal end of the cannula. A retraction spring biases the trocar to its withdrawn position. A latch latches the trocar, in opposition to the retraction spring, for reciprocal movement between the fully extended and intermediate positions. A trip member couples the trocar to the latch member when the trocar moves from the fully extended position to the intermediate position, and trips the latch member when the trocar returns toward the fully extended position to unlatch the trocar and permit it to be moved to the withdrawn position by the retraction spring.
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Citations
24 Claims
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1. A safety trocar instrument for piercing the wall of an anatomical cavity to provide communication with the inside of the cavity, said trocar instrument comprising:
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(a) a tubular cannula; (b) an elongate trocar, having a sharp piercing point, mounted for axial reciprocal movement within said cannula between a withdrawn rest position in which said point is received within and shielded by the distal end of said cannula, a fully extended position in which said point is exposed beyond the distal end of said cannula, and an intermediate position retracted toward the rest position from the fully extended position in which said point is also exposed beyond the distal end of said cannula; (c) means for biasing said trocar to its withdrawn position; (d) latch means for latching said trocar, in opposition to said biasing means, for reciprocal movement between the fully extended position and the intermediate position; and (e) trip means coupling said trocar to said latch means when said trocar moves from the fully extended position to the intermediate position, and tripping said latch means when said trocar returns toward said fully extended position to unlatch said trocar and thereby permit said trocar to be moved to the withdrawn rest position by said biasing means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A safety trocar instrument for piercing the wall of an anatomical cavity to provide communication with the inside of the cavity, said trocar instrument comprising:
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(a) a tubular cannula; (b) an elongate trocar, having a sharp piercing point, mounted for axial reciprocal movement within said cannula between a withdrawn rest position in which said point is received within and shielded by the distal end of said cannula and a fully extended position in which said point is exposed beyond the distal end of said cannula; (c) means for biasing said trocar to its withdrawn position; (d) latch means for latching said trocar in opposition to said biasing means; and (e) trip means for tripping said latch means to unlatch said trocar and thereby permit said trocar to be moved to its withdrawn rest position by said biasing means; and (f) lost-motion coupling means coupling said trip means to said trocar and permitting said trocar, when latched by said latch means, to reciprocate between the fully extended position and an intermediate retracted position in which said trocar point is also exposed beyond the distal end of said cannula, said trocar arming said trip means when moved to the intermediate retracted position and actuating said trip means to trip said latch means when returned toward the fully extended position. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. A safety trocar instrument for piercing the wall of an anatomical cavity to provide communication with the inside of the cavity, said trocar instrument comprising:
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(a) a main body-cannula subassembly including; (1) a main body; (2) a tubular cannula projecting from the main body; and (b) a trocar subassembly formed to mate with said main body-cannula subassembly and including; (1) a housing; (2) an elongate trocar, having a sharp piercing point, mounted for axial reciprocal movement relative to said housing between a withdrawn rest position, a fully extended position, and an intermediate position retracted from the fully extended position toward the withdrawn position, said trocar being formed to be coaxially received in said cannula with said point exposed beyond the distal end thereof in the fully extended and intermediate positions, and with said point withdrawn into and shielded by the distal end of said cannula in the withdrawn position; (3) means for biasing said trocar toward its withdrawn position; (4) plunger means with which said trocar subassembly can be manually urged toward said main body-cannula subassembly to an armed stage to move said trocar to its fully extended position; (5) latch means for latching said trocar, in opposition to said biasing means, for reciprocal movement between the fully extended position and the intermediate position when the instrument is in the armed stage; and (6) trip means coupling said trocar to said latch means when said trocar moves from the fully extended position to the intermediate position in the armed stage, said trip means thereafter tripping said latch means when said trocar returns toward the fully extended position from the intermediate position thereby to permit said trocar to be urged to its withdrawn position by said biasing means.
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Specification