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Date of download: 10/8/2017 Copyright © ASME. All rights reserved. From: Spring-to-Spring Balancing as Energy-Free Adjustment Method in Gravity Equilibrators J. Mech. Des. 2011;133(6): doi: / Figure Legend: The rolling link spring-to-spring balancer (a) consists of a bar rolling on a support disk, with two fixed pulleys on either end. The wires connected to the springs run over the fixed disks at the end of the rolling bar. As shown in (b) the system works by creating two isosceles triangles having one side with length L/2 lying back to back. In order for the wires to be parallel to the isosceles triangles (c) the radius of the rolling links rr must be equal to rp2 . In (d) the wrap angles of the wire are determined, and it is shown that Σβi=π/2, independent of ϕ. Therefore, the balancing is exact.
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Date of download: 10/8/2017 Copyright © ASME. All rights reserved. From: Spring-to-Spring Balancing as Energy-Free Adjustment Method in Gravity Equilibrators J. Mech. Des. 2011;133(6): doi: / Figure Legend: Practical implementation of a gravity equilibrator using the parallelogram storage spring principle with zero-free-length spring as shown in Fig. . In the configuration shown the parallelogram is locked (black knob). When the weight arm is in horizontal position, it can be locked, in which case the parallelogram can be unlocked and moved upward (for a greater payload) or downward (for smaller payload).
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Date of download: 10/8/2017 Copyright © ASME. All rights reserved. From: Spring-to-Spring Balancing as Energy-Free Adjustment Method in Gravity Equilibrators J. Mech. Des. 2011;133(6): doi: / Figure Legend: Practical implementation of rolling link adjustment mechanism in a kitchen cabinet. The kitchen cabinet moves in a 90 degree arc by means of a parallelogram, and its mass is balanced by a three-pulley basic gravity equilibrator attached to the bottom arm. When the cabinet is in its lowest position, it is fixed and the rolling link spring-to-spring balancer is unlocked. Mass can be added to or removed from the cabinet, and the balancer spring is adjusted accordingly by means of the rolling link balancer.
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Date of download: 10/8/2017 Copyright © ASME. All rights reserved. From: Spring-to-Spring Balancing as Energy-Free Adjustment Method in Gravity Equilibrators J. Mech. Des. 2011;133(6): doi: / Figure Legend: The actual embodiment of the practical implementation of rolling link adjustment mechanism in a kitchen cabinet. The schematic representation is given in Fig. .
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Date of download: 10/8/2017 Copyright © ASME. All rights reserved. From: Spring-to-Spring Balancing as Energy-Free Adjustment Method in Gravity Equilibrators J. Mech. Des. 2011;133(6): doi: / Figure Legend: The rolling link spring-to-spring balancing mechanism (a) as implemented in the balanced kitchen cabinet. Two parallel support disks are used, to allow the wires to pass through the centre. In (b) and (c), the actual embodiment is shown. The schematic representation is given in Fig. .
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Date of download: 10/8/2017 Copyright © ASME. All rights reserved. From: Spring-to-Spring Balancing as Energy-Free Adjustment Method in Gravity Equilibrators J. Mech. Des. 2011;133(6): doi: / Figure Legend: Solution to balance the mass of the rolling link. Assuming that the centre of mass of the rolling bar coincides with the centre of the rolling link, the mass can be balanced by means of a zero-free-length spring. Essentially it is a rolling link variant of the basic gravity equilibrator, and the dimensions are equivalent to the ones shown in Fig. . Distance a may of course be greater than the radius of the fixed disk.
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Date of download: 10/8/2017 Copyright © ASME. All rights reserved. From: Spring-to-Spring Balancing as Energy-Free Adjustment Method in Gravity Equilibrators J. Mech. Des. 2011;133(6): doi: / Figure Legend: Basic gravity equilibrator using a zero-free-length spring balancing a mass m with lengths a, r, L, which satisfies the balancing condition (4) for any angle ϕ
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Date of download: 10/8/2017 Copyright © ASME. All rights reserved. From: Spring-to-Spring Balancing as Energy-Free Adjustment Method in Gravity Equilibrators J. Mech. Des. 2011;133(6): doi: / Figure Legend: The parallelogram spring-to-spring balancer employed as storage spring for the gravity equilibrator (using zero-free-length springs). In the horizontal position the weight arm is locked and the height of the parallelogram can be changed in an energy-free way (a). Once adapted to the new weight (b), the top end of the parallelogram is fixed and the system is again statically balanced for any ϕ.
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