Support arm
First Claim
1. A support arm, comprising:
- a first strut having a proximal portion;
a proximal link pivotally coupled to the proximal portion of the first strut at a first proximal joint, the proximal link comprising a cam, wherein the first strut is rotatable relative to the cam about the first proximal joint;
a distal link pivotally coupled to a distal portion of the first strut at a first distal joint, wherein the first strut is rotatable relative to the distal link about the first distal joint; and
a cam follower coupled to the first strut, the cam follower contacting a cam surface of the cam at a first contact point;
the cam and the cam follower cooperating to apply a cam moment to the first strut; and
the cam moment being sufficient to balance a load supported by the distal link, further comprising a means for urging the cam follower against the cam surface of the cam wherein the means for urging the cam follower against the cam surface of the cam comprises a spring, and further comprising an adjustment mechanism for varying a characteristic of the spring, wherein the adjustment mechanism comprises a spring plate coupled to the spring.
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Accused Products
Abstract
An apparatus for supporting a load is disclosed. A support arm in accordance with an exemplary embodiment of present invention comprises a first strut, a second strut, a proximal link, and a distal link. A proximal portion of the first strut is pivotally coupled to the proximal link at a first proximal joint. Additionally, a proximal portion of the second strut is pivotally coupled to the proximal link at a second proximal joint. A distal end of the second strut is pivotally coupled to the distal link at a second distal joint. A distal end of the first strut is pivotally coupled to the distal link at a first distal joint. The support arm also includes a cam mechanism comprising a cam and a cam follower.
272 Citations
25 Claims
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1. A support arm, comprising:
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a first strut having a proximal portion; a proximal link pivotally coupled to the proximal portion of the first strut at a first proximal joint, the proximal link comprising a cam, wherein the first strut is rotatable relative to the cam about the first proximal joint; a distal link pivotally coupled to a distal portion of the first strut at a first distal joint, wherein the first strut is rotatable relative to the distal link about the first distal joint; and a cam follower coupled to the first strut, the cam follower contacting a cam surface of the cam at a first contact point;
the cam and the cam follower cooperating to apply a cam moment to the first strut; and
the cam moment being sufficient to balance a load supported by the distal link, further comprising a means for urging the cam follower against the cam surface of the cam wherein the means for urging the cam follower against the cam surface of the cam comprises a spring, and further comprising an adjustment mechanism for varying a characteristic of the spring, wherein the adjustment mechanism comprises a spring plate coupled to the spring. - View Dependent Claims (2, 3)
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4. A support arm, comprising:
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a first strut having a proximal portion; a proximal link pivotally coupled to the proximal portion of the first strut at a first proximal joint, the proximal link comprising a cam, wherein the first strut is rotatable relative to the cam about the first proximal joint; a distal link pivotally coupled to a distal portion of the first strut at a first distal joint, wherein the first strut is rotatable relative to the distal link about the first distal joint; and a cam follower coupled to the first strut, the cam follower contacting a cam surface of the cam at a first contact point;
the cam and the cam follower cooperating to apply a cam moment to the first strut; and
the cam moment being sufficient to balance a load supported by the distal link, wherein a strut angle is defined by a longitudinal axis of the first strut and a direction of gravitational pull, a contact angle is defined by a line that is perpendicular to the longitudinal axis of the first strut and a tangent line that is generally tangent to both the cam follower and the cam surface and that extends through the first contact point, the cam provides a reaction force supporting the cam follower when the cam follower is urged against the cam, the cam moment is provided by a moment creating component of the reaction force, and the cam is shaped so that the moment creating component of the reaction force varies as the first strut rotates relative to the cam. - View Dependent Claims (5, 6, 7, 8, 9, 10)
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11. A support arm, comprising:
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a first strut having a proximal portion; a proximal link pivotally coupled to the proximal portion of the first strut at a first proximal joint, the proximal link comprising a cam, wherein the first strut is rotatable relative to the cam about the first proximal joint; a distal link pivotally coupled to a distal portion of the first strut at a first distal joint, wherein the first strut is rotatable relative to the distal link about the first distal joint; and a cam follower coupled to the first strut, the cam follower contacting a cam surface of the cam at a first contact point;
the cam and the cam follower cooperating to apply a cam moment to the first strut; and
the cam moment being sufficient to balance a load supported by the distal link, wherein the cam is shaped so that a deflection of a spring varies as the first strut rotates relative to the cam. - View Dependent Claims (12)
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13. A support arm, comprising:
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a first strut having a proximal portion; a proximal link pivotally coupled to the proximal portion of the first strut at a first proximal joint, the proximal link comprising a cam, wherein the first strut is rotatable relative to the cam about the first proximal joint; a distal link pivotally coupled to a distal portion of the first strut at a first distal joint, wherein the first strut is rotatable relative to the distal link about the first distal joint; and a cam follower coupled to the first strut, the cam follower contacting a cam surface of the cam at a first contact point;
the cam and the cam follower cooperating to apply a cam moment to the first strut; and
the cam moment being sufficient to balance a load supported by the distal link, wherein the cam is shaped so that a radius of the cam varies when the first strut rotates relative to the cam. - View Dependent Claims (14)
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15. A support arm, comprising:
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a first strut having a proximal portion; a proximal link pivotally coupled to the proximal portion of the first strut at a first proximal joint, the proximal link comprising a cam, wherein the first strut is rotatable relative to the cam about the first proximal joint; a distal link pivotally coupled to a distal portion of the first strut at a first distal joint, wherein the first strut is rotatable relative to the distal link about the first distal joint; and a cam follower coupled to the first strut, the cam follower contacting a cam surface of the cam at a first contact point;
the cam and the cam follower cooperating to apply a cam moment to the first strut; and
the cam moment being sufficient to balance a load supported by the distal link, wherein the cam is shaped so that a radius of curvature of the cam varies when the first strut rotates relative to the cam. - View Dependent Claims (16, 17, 18, 19, 20)
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21. A support arm, comprising:
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a first strut having a proximal portion; a proximal link pivotally coupled to the proximal portion of the first strut at a first proximal joint, the proximal link comprising a cam, wherein the first strut is rotatable relative to the cam about the first proximal joint; a distal link pivotally coupled to a distal portion of the first strut at a first distal joint, wherein the first strut is rotatable relative to the distal link about the first distal joint; and cam follower coupled to the first strut, the cam follower contacting a cam surface of the cam at a first contact point;
the cam and the cam follower cooperating to apply a cam moment to the first strut; and
the cam moment being sufficient to balance a load supported by the distal link, wherein the cam surface has a substantially continually changing radius of curvature.
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22. A support arm, comprising:
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a first strut having a proximal portion; a proximal link pivotally coupled to the proximal portion of the first strut at a first proximal joint, the proximal link comprising a cam, wherein the first strut is rotatable relative to the cam about the first proximal joint; a distal link pivotally coupled to a distal portion of the first strut at a first distal joint, wherein the first strut is rotatable relative to the distal link about the first distal joint; and a cam follower coupled to the first strut, the cam follower contacting a cam surface of the cam at a first contact point;
the cam and the cam follower cooperating to apply a cam moment to the first strut; and
the cam moment being sufficient to balance a load supported by the distal link, wherein the cam has a substantially continually changing radius. - View Dependent Claims (23)
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24. A support arm, comprising:
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a first strut having a proximal portion; a proximal link pivotally coupled to the proximal portion of the first strut at a first proximal joint, the proximal link comprising a cam, wherein the first strut is rotatable relative to the cam about the first proximal joint; a distal link pivotally coupled to a distal portion of the first strut at a first distal joint, wherein the first strut is rotatable relative to the distal link about the first distal joint; and a cam follower coupled to the first strut, the cam follower contacting a cam surface of the cam at a first contact point;
the cam and the cam follower cooperating to apply a cam moment to the first strut; and
the cam moment being sufficient to balance a load supported by the distal link, further comprising a means for urging the cam follower against the cam surface of the cam wherein the means for urging the cam follower against the cam surface of the cam comprises a spring, and further comprising an adjustment mechanism for varying a characteristic of the spring wherein the adjustment mechanism varies a pre-load of the spring.
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25. A support arm, comprising:
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a first strut having a proximal portion; a proximal link pivotally coupled to the proximal portion of the first strut at a first proximal joint, the proximal link comprising a cam, wherein the first strut is rotatable relative to the cam about the first proximal joint; a distal link pivotally coupled to a distal portion of the first strut at a first distal joint, wherein the first strut is rotatable relative to the distal link about the first distal joint; and a cam follower coupled to the first strut, the cam follower contacting a cam surface of the cam at a first contact point;
the cam and the cam follower cooperating to apply a cam moment to the first strut; and
the cam moment being sufficient to balance a load supported by the distal link, further comprising a means for urging the cam follower against the cam surface of the cam wherein the means for urging the cam follower against the cam surface of the cam comprises a spring, and further comprising an adjustment mechanism for varying a characteristic of the spring wherein the adjustment mechanism varies a length of the spring.
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Specification