Mechanism for screw drive and syringe plunger engagement/disengagement
First Claim
1. The combination comprising:
- a lead screw;
traveler means actuable between states of threaded engagement and disengagement with said lead screw, said traveler means including biasing means for biasing said traveler means in said state of engagement and in said state of disengagement, said biasing means producing an over-center action during movement of said traveler means between said state of engagement and said state of disengagement;
actuating means, selectively operable, for actuating said traveler means; and
means for coupling said actuating means to said traveler means to allow limited relative movement between said actuating means and said traveler means, such that said traveler means moves to said state of engagement independently of said actuating means after said biasing means has moved over center, and further such that said traveler means begins to engage said lead screw in moving to said state of engagement only after said biasing means has moved over center.
5 Assignments
0 Petitions
Accused Products
Abstract
A mechanism for screw drive and syringe plunger engagement and disengagement for a syringe infusion pump, wherein a split-nut pair are moveable into and out of engagement with a lead screw by means of rotary cam control, the rotary cam being keyed with a crank disk that is coupled to a crank arm, which operates as the syringe plunger mover. The crank arm is rotatable into and out of engagement with the syringe plunger, such rotation also causing the split-nut pair to move into and out of engagement with the lead screw. Index and cam means are carried by the crank arm to aid in proper alignment with the syringe plunger, and a sensor is provided for monitoring proper engagement of the crank arm with the plunger.
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Citations
51 Claims
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1. The combination comprising:
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a lead screw; traveler means actuable between states of threaded engagement and disengagement with said lead screw, said traveler means including biasing means for biasing said traveler means in said state of engagement and in said state of disengagement, said biasing means producing an over-center action during movement of said traveler means between said state of engagement and said state of disengagement; actuating means, selectively operable, for actuating said traveler means; and means for coupling said actuating means to said traveler means to allow limited relative movement between said actuating means and said traveler means, such that said traveler means moves to said state of engagement independently of said actuating means after said biasing means has moved over center, and further such that said traveler means begins to engage said lead screw in moving to said state of engagement only after said biasing means has moved over center. - View Dependent Claims (2)
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3. The combination comprising:
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a lead screw; traveler means actuable between states of threaded engagement and disengagement with said lead screw, said traveler means including biasing means for biasing said traveler means in said state of engagement and in said state of disengagement, said biasing means producing an over-center action during movement of said traveler means between said state of engagement and said state of disengagement; actuating means, selectively operable, for actuating said traveler means; and means for coupling said actuating means to said traveler means to allow limited relative movement between said actuating means and said traveler means, such that said traveler means moves to said state of disengagement independently of said actuating means after said biasing means has moved over center, and further such that said traveler means begins to disengage said lead screw in moving to said state of disengagement only after said biasing means has moved over center. - View Dependent Claims (4)
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5. The combination comprising:
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a lead screw; traveler means actuable between states of threaded engagement and disengagement with said lead screw, said traveler means including biasing means for biasing said traveler means in said state of engagement and in said state of disengagement, said biasing means producing an over-center action during movement of said traveler means between said state of engagement and said state of disengagement; actuating means, selectively operable, for actuating said traveler means; and means for coupling said actuating means to said traveler means to allow limited relative movement between said actuating means and said traveler means, such that said traveler means moves between said state of engagement and said state of disengagement independently of said actuating means after said biasing means has moved over center, and further such that said traveler means begins to engage said lead screw in moving to state of engagement, and begins to disengage said lead screw in moving to said state of disengagement, only after said biasing means has moved over center. - View Dependent Claims (6, 7, 8)
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9. The combination comprising:
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a lead screw; a pair of split nuts disposed on opposite sides of said lead screw and mounted for movement into and out of engagement with said lead screw; rotary cam means for controlling the movement of said split nuts; actuating means, selectively operable, for actuating said rotary cam means; first biasing means for biasing said rotary cam means in either one of opposite rotational states, said first biasing means producing an over-center action with said rotary cam means during rotation between said opposite rotational states; and means for coupling said actuating means to said rotary cam means to allow limited relative movement between said actuating means and said rotary cam means, such that said rotary cam means controls movement of said split nuts independently of said actuating means after said rotary cam means has travelled over center, and further such that rotation of said rotary cam means in a first direction between said opposite rotational states causes movement of said split nuts into engagement with said lead screw only after said rotary cam means has travelled over center. - View Dependent Claims (10, 11, 12, 13, 14)
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15. The combination comprising:
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a lead screw; a plurality of threaded members mounted for movement into and out of engagement with said lead screw; control means for controlling movement of said threaded members; first biasing means for biasing said control means in a disengaged state when said threaded members are fully disengaged from said lead screw, and in an engaged state when said threaded members are fully engaged to said lead screw, said first biasing means producing an over-center action with said control means during movement between said engaged state and said disengaged state; and means for coupling said actuating means to said control means to allow limited relative movement between said actuating means and said control means, such that said control means controls movement of said threaded members independently of said actuating means after said control means has travelled over center, and further such that said threaded members begin to engage said lead screw only after said control means has travelled over center towards said engaged state. - View Dependent Claims (16, 17, 18, 19, 20, 21)
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22. In a syringe pump for delivering a pump stroke to a syringe having a syringe plunger, the combination comprising:
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means for releasably holding the syringe in the syringe pump; plunger mover means mounted for rotation between a first position and a second position, said plunger mover means in said first position disposed in axial alignment with the free end of the plunger, and said plunger mover means in said second position providing clearance to freely install the syringe in the syringe pump regardless of the linear position of said plunger mover means relative to the free end of the syringe plunger; means for imparting relative linear motion between said plunger mover means and the syringe along the axis of the syringe plunger; and index means, carried by said plunger mover means, for indexing said plunger mover means, when in said second position, in proper linear alignment for full engagement with the free end of the syringe plunger when said plunger mover means is rotated to said first position, said index means indexing said plunger mover means when in said second position by partial engagement of said plunger mover means with the free end of the syringe plunger. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
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33. In a syringe pump for delivering a pump stroke to a syringe having a syringe plunger, the combination comprising:
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a lead screw; a pair of split nuts disposed on opposite sides of said lead screw and mounted for movement into and out of engagement with said lead screw; control means for controlling the movement of said split nuts; and plunger mover means, coupled to said control means, for pushing against the free end of the syringe plunger, said plunger mover means being mounted for selective rotation between a first position, in which said plunger mover means engages the free end of the plunger and actuates said control means to an engaged state in which said split nuts are engaged to said lead screw, and a second position, in which the plunger mover means is disengaged from the free end of the plunger and actuates said control means to a disengaged state in which said split nuts are disengaged from said lead screw. - View Dependent Claims (34, 35, 36, 37, 38, 39, 40)
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41. In a syringe pump for delivering a pump stroke to a syringe having a syringe plunger, the combination comprising:
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a lead screw; traveler means actuable between states of threaded engagement and disengagement with said lead screw, said traveler means including a plurality of threaded members disposed about said lead screw such that in said state of engagement the forces exerted by said threaded members on said lead screw are substantially balanced relative to one another; and plunger mover means, coupled to said traveler means, for pushing against the free end of the syringe plunger, said plunger mover means being mounted for selective rotation between a first position, in which said plunger mover means engages the free end of the plunger and actuates said traveler means to said state of engagement with said lead screw, and a second position, in which said plunger mover means is disengaged from the free end of the plunger and actuates said traveler means to said state of disengagement with said lead screw. - View Dependent Claims (42, 43, 44, 45, 46, 47, 48, 49, 50, 51)
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Specification