SupportarmWord格式文档下载.docx

1、BACKGROUND OF THE INVENTIONThere are many applications in which lifts, arms, counter-balances, and force and torque providing mechanisms may be useful. Mechanisms such as these can be used to raise and lower a variety of items including, but not limited to, the examples listed below: o video monitor

2、s of all sizeso furniture work surfaceso production assembly toolso work load transfer equipmento kitchen cabinetso vertically oriented exercise equipmento robot control deviceso windowsThese mechanisms can also be used to provide forces and torques in other orientations （e.g., horizontal or radial）

3、. Examples of such applications include, but are not limited to:o continuous constant force feeding systems for machine toolso horizontally oriented exercise equipmento drawer closing applicationso door closing applicationOne application for such a mechanism is the support of a display monitor for a

4、 personal computer. Personal computers and/or display monitors are often placed directly on a desk or on a computer case. However, to increase desk space, or to respond to the ergonomic needs of different operators, computer monitors are sometimes mounted on elevating structures. Alternatively, moni

5、tors are mounted to a surface such as a wall, instead of placing the monitor on a desk or a cart.However, personal computers and/or display monitors are often used by multiple operators at different times during a day. In some settings, one computer and/or monitor may be used by multiple people of d

6、ifferent sizes and having different preferences in a single day. Given the differences in peoples size and differences in their preferences, a monitor or display adjusted at one setting for one individual is highly likely to be inappropriate for another individual. For instance, a child would have d

7、ifferent physical space needs than an adult using the same computer and monitor.In addition, operators are using computers for longer periods of time which increases the importance of comfort to the operator. An operator may choose to use the monitor as left by the previous user despite the discomfo

8、rt, annoyance and inconvenience experienced by a user who uses settings optimized for another individual, which may even result in injury after prolonged use.Moreover, as monitors grow in size and weight, ease of adjustability is an important consideration. For monitors requiring frequent adjustment

9、, adjustability for monitors has been provided using an arm coupled with gas springs, where the arm is hingedly coupled with the desk or a vertical surface. However, the gas springs are costly and wear out over time. In addition, the gas springs require a significant amount of space, for instance ar

10、m length, which can be at a premium in certain applications, such as in hospitals.Thus, there is a need for a support are that is less costly to manufacture and maintain, has increased reliability, allows easy adjustability, is scalable to many different sized loads, is adaptable to provide a long r

11、ange of travel, and is adaptable to provide constant support force as the load is being positioned.SUMMARY OF THE INVENTIONThe present invention relates generally to an apparatus for supporting a load. A support arm in accordance with an exemplary embodiment of present invention comprises a first st

12、rut, 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 second strut is pivotally coupled to the proximal link at a second proximal joint. A distal end of t

13、he 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. In some useful embodiments of the curre

14、nt invention, the cam mechanism converts the force of a spring （e.g., a compression, extension, torsional and/or leaf spring） to a sinusoidal moment load of the rotating arm. In some embodiments, the cam mechanism may comprise an energy source for urging the cam follower against a cam surface of the

15、 cam. When this is the case, the support arm may also include an adjustment mechanism for varying the output of the energy source.In some embodiments, a spring is provided for urging the cam follower against the cam surface of the cam. When this is the case, an adjustment mechanism for varying the p

16、re-load of the spring may also be provided. In one exemplary embodiment, the adjustment mechanism comprises a spring plate coupled to the spring and a screw that is capable of adjusting the position of the spring plate. Other ways of adjusting the energy output of the spring may be possible without

17、deviating from the spirit and scope of the present invention. The present invention describes an apparatus to provide these capabilities at a much lower cost compared to traditional arms based on gas spring technology.DESCRIPTION OF THE DRAWINGSFIG. 1 is a diagrammatic representation of a support ar

18、m in accordance with an exemplary embodiment of the present invention.FIG. 2 is an additional diagrammatic representation of support arm shown in the previous figure.FIG. 3 is an enlarged diagram illustrating the forces acting on cam follower shown in the previous figure.FIG. 4 is a diagrammatic rep

19、resentation of a support arm in accordance with an additional exemplary embodiment of the present invention.FIG. 5 is an additional diagrammatic representation of the support arm shown in the previous figure.FIG. 6 is an additional diagrammatic representation of the support arm shown in the previous

20、 figure.FIG. 7 is a diagrammatic representation of a support arm in accordance with an exemplary embodiment of the present invention.FIG. 8 is an additional diagrammatic representation of support arm shown in the previous figure.FIG. 9 is a side view of a support arm in accordance with an additional

21、 exemplary embodiment of the present invention.FIG. 10 is a perspective view of the support arm shown in the previous figure.FIG. 11 is a side view of the support arm shown in the previous figure.FIG. 12 is a side view of the support arm shown in the previous figure.FIG. 13 is a cross sectional view

22、 of the support arm 100 shown in the previous figure.FIG. 14 is a perspective view of support arm 100 shown in the previous figure.FIG. 15 is a side view of a support arm in accordance with an additional exemplary embodiment of the present invention.FIG. 16 is a top view of the support arm shown in

23、the previous figure.FIG. 17 is an exploded view of a pivot mechanism 220 in accordance with an exemplary embodiment of the present invention.DETAILED DESCRIPTIONThe following detailed description should be read with reference to the drawings, in which like elements in different drawings are numbered

24、 identically. The drawings, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the invention. Examples of constructions, materials, dimensions, and manufacturing processes are provided for selected elements. All other elements employ that which

25、 is known to those of skill in the field of the invention. Those skilled in the art will recognize that many of the examples provided have suitable alternatives that can be utilized.FIG. 1 is a diagrammatic representation of a support arm 100 in accordance with an exemplary embodiment of the present

26、 invention. Support arm 100 includes a first strut 102, a second strut 104, a proximal link 106, and a distal link 108. In the embodiment of FIG. 1, a proximal portion of the first strut 102 is pivotally coupled to proximal link 106 at a first proximal joint 122. Additionally, a proximal portion of

27、second strut 104 is pivotally coupled to proximal link 106 at a second proximal joint 124. A distal end of second strut 104 is pivotally coupled to distal link 108 at a second distal joint 126. A distal end of first strut 102 is pivotally coupled to distal link 108 at a first distal joint 128.In the

28、 embodiment of FIG. 1, proximal link 106 comprises a cam 130 having a first cam surface 132. Support arm 100 of FIG. 1 includes a cam following assembly 134 comprising a cam follower 136 and a spring 138 that is capable of urging cam follower 136 against first cam surface 132 of cam 130. In the embo

29、diment of FIG. 1, cam follower 136 and spring 138 are disposed within a lumen 140 defined by first strut 102. Also in the embodiment of FIG. 1, cam follower 136 comprises a roller 142 that is rotationally coupled to a distal end of spring 138. In the embodiment of FIG. 1, roller 142 is supported suc

30、h that it rotates about a rotational axis. With reference to FIG. 1, it will be appreciated that a proximal end of spring 138 is seated against a spring plate 144.FIG. 2 is an additional diagrammatic representation of support arm 100 shown in the previous figure. In the embodiment of FIG. 2, distal

31、link 108 supports a load. It is to be appreciated that various loads may be supported using support arm 100 without deviating from the spirit and scope of the present invention. In FIG. 2, the effect of gravity on the load is illustrated using an arrow labeled FL. A direction of gravitational pull illustrate using an arrow labeled DG in FIG. 2. With reference to FIG. 2, it will be appreciated that the arrow labeled FL and the arrow labeled DG are generall