US20100001153A1

US20100001153A1 - Cam lock for cantilever mounting device

Info

Publication number: US20100001153A1
Application number: US12/167,801
Authority: US
Inventors: Brett Stenhouse; Michael Townsend; Ray Zuckerman; John C. Donachy
Original assignee: OmniMount Systems Inc
Current assignee: Ergotron Inc
Priority date: 2008-07-03
Filing date: 2008-07-03
Publication date: 2010-01-07

Abstract

A cantilever mounting device includes a front member on which an object is mounted and a back member for attachment to a load-bearing surface. A first arm is connected to the back member to form a rotatable first joint. A second arm is connected to the first arm to form a rotatable second joint. The front member is connected to the second arm to form a rotatable third joint. The first joint includes a first cam including a first lever and a first shaft for connecting the back member to the first arm. The first cam allows rotation about an axis of the first joint when the first lever is set to a first adjustment position. The first cam does not allow rotation about the axis of the first joint when the first lever is set to a first locked position.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
This invention relates to tension adjustment for a cantilever mounting device.
2. Description of Related Art
Flat panel displays have become increasingly popular in home entertainment systems. Generally, flat panel displays have a limited viewing angle, thus making the positioning of the display important to a viewer. Flat panel displays are typically placed on stands or are mounted to a wall by flat panel mounting devices. These mounting devices include articulating joints and are conventionally preset with an optimal joint/tilt tension during manufacturing to the joints of the articulating components and tilt mechanisms. The preset tension allows the flat panel mounting device to steadily and predictably hold a display in place. However, periodic adjustment is required to readjust the tension of the joints and tilt mechanism to maintain a desired viewing position. Furthermore, if a user decides to change a viewing position of the display, the present joint tension may first need to be loosened to allow repositioning of the mounting device.
Conventionally, the end user is required to make manual adjustments to the joints using specialized tools to provide the articulating components with the correct amount of tension or friction to hold the mounting device in place. However, users without proper tools must resort to professional installers to provide periodic tensioning adjustment. In either case, the purchase of tools or services is costly and inconvenient. Therefore, a tension adjustment of the mounting device has become difficult. The present solutions do not provide the ability to quickly and conveniently maintain the proper operation of a mounting device.

SUMMARY OF THE INVENTION

Various embodiments of the present invention overcome these drawbacks of the prior art and provide a cantilever mounting device having articulating joints and a cam for allowing adjustment of the joint tension by a flip of a lever from a locked position to an adjustment position. The adjustment position allows the adjustment of tension at a corresponding articulating joint. In this manner, the repositioning of the mounting device to a desired viewing angle is provided. The present invention is not limited to mounting flat-panel displays as any display suitable for mounting can be utilized.
Accordingly, one embodiment of the invention is a cantilever mounting device that includes a front member on which an object is mounted and a back member for attachment to a load-bearing surface. A first arm connected to the back member forms a rotatable first joint. A second arm connected to the first arm forms a rotatable second joint. The front member connected to the second arm forms a rotatable third joint. The first joint includes a first cam including a first lever and a first shaft for connecting the back member to the first arm. The first lever is set in a first locked position and a first adjustment position. The first cam allows rotation about an axis of the first joint when the first lever is set to the first adjustment position and the first cam does not allow rotation about the axis of the first joint when the first lever is set to the first locked position.
Furthermore, the first cam includes an adjustment dial. The first cam allows rotation of the adjustment dial when the first lever is set to the first adjustment position, and the first cam does not allow rotation of the adjustment dial when the first lever is set to the first locked position. The rotation of said adjustment dial increases or decreases a tension of the first Joint. The first cam includes a first base, a first pivot pin, and an adjustment dial. The first pivot pin is inserted into the first lever and the first shaft to secure the first lever, the first base, and the first pivot pin to a first end of the first shaft. The first adjustment dial is connected to a second end of the first shaft. The first locked position of the first lever is provided perpendicular to the first shaft, and the first adjustment position of the first lever is provided parallel to the first shaft. The second joint includes a second cam including a second lever, a second shaft, and a tension pin for connecting the first arm to the second arm. The second lever is set in a second locked position and a second adjustment position. The second cam allows rotation about an axis of the second joint when the second lever is set to the second adjustment position and the second cam does not allow rotation about the axis of the second joint when the second lever is set to the second locked position. The second cam allows rotation of the tension pin when the second lever is set to the second adjustment position, and the second cam does not allow rotation of the tension pin when the second lever is set to the second locked position. The rotation of the tension pin increases or decreases a tension of the second joint. The second cam includes a second base and a second pivot pin. The tension pin is inserted into the second shaft. The second pivot pin is inserted into the second lever and the tension pin to secure the second lever, the second base, the second pivot pin and the tension pin to the second shaft. The tension pin is a screw.
In another embodiment of the present invention, a cantilever mounting, device includes a front member on which an object is mounted and a back member for attachment to a load-bearing surface. A first arm connected to the back member forms a rotatable first joint. A second arm connected to the first arm forms a rotatable second joint. The front member connected to the second arm forms a rotatable third joint. The third joint includes a third cam including a third lever and a third shaft. The third lever is set in a locked position and an adjustment position. The third cam allows rotation about the axis of the third joint when the third lever is set to the adjustment position. The third cam does not allow rotation about an axis of the third joint when the third lever is set to the locked position.
Furthermore, the third cam allows rotation of the third shaft when the third lever is set to the adjustment position, and the third cam does not allow rotation of the third shaft when the third lever is set to the locked position. The rotation of the third shaft increases or decreases a tension of the third joint. The third cam includes a third base, a third pivot pin, a top pivot, and a bottom pivot. The third pivot pin is inserted into the third lever and the third shaft to secure the third lever, the third base, and the top pivot pin to a first end of the third shaft. The bottom pivot is connected to a second end of the third shaft. A tilt link is connected to the top pivot and the bottom pivot. The tilt link connects the third cam to the front member. The tilt link provides rotation about an axis perpendicular to the axis of the third joint.
A method for adjusting the position of a cantilever mounting device includes applying force to a first lever of a first cam for reducing a tension of a first joint and for setting the first lever to a first adjustment position. A first arm is rotated relative to a back member about the first joint when the first lever is in the first adjustment position. Force is applied to the first lever for increasing the tension of the first joint and for setting the first lever to a first locked position such that the first arm is locked in place relative to the back member.
Furthermore, an adjustment dial of the first cam is rotated to reduce the tension of the first joint when the first lever is set to the first adjustment position. Force is applied to a second lever of a second cam for reducing a tension of a second joint and for setting the second lever to a second adjustment position. A second arm is rotated relative to the first arm about the second joint when the second lever is in the second adjustment position. Force is applied to the second lever for increasing the tension of the second joint when the second lever is in the second adjustment position. Force is applied to the second lever for increasing the tension of the second joint and for setting the second lever to a second locked position such that the second arm is locked in place relative to the first arm. Force is applied to a third lever of a third cam for reducing a tension of a third joint and for setting the third lever to a third adjustment position. A front member is rotated relative to the second arm about the third joint when the third lever is in the adjustment position. Force is applied to the third lever for increasing the tension of the third joint and for setting the third lever to a third locked position such that the front member is locked in place relative to the second arm. The front member is tilted about an axis perpendicular to the third joint.
Other features and advantages of the invention will be apparent from the following detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, various features of embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of a cantilever mounting device of the invention.

FIG. 2A is a perspective view of one embodiment of a front plate of the invention.

FIG. 2B is a perspective view of one embodiment of a back plate of the invention.

FIG. 2C is a perspective view of one embodiment of a lower arm of the invention.

FIG. 2D is a perspective view of one embodiment of an upper arm of the invention.

FIG. 3 is an exploded view of one embodiment of a shoulder joint of the invention.

FIG. 4A is a partial side view of one embodiment of a lever of the invention.

FIG. 4B is an exploded view of one embodiment of a shoulder cam of the invention.

FIG. 5A is a side view of one embodiment of an elbow joint of the invention.

FIG. 5B is an exploded view of one embodiment of an elbow cam of the invention.

FIG. 5C is a sectional view of one embodiment of an elbow joint of the invention.

FIG. 6A is a side view of one embodiment of a wrist joint of the invention.

FIG. 6B is side view of one embodiment of a wrist cam of the invention.

FIG. 6C is an exploded view of one embodiment of a wrist cam of the invention.

FIG. 6D is a sectional view of one embodiment of a wrist joint of the invention.

FIG. 6E is an exploded view of one embodiment of a bottom pivot of the wrist cam of the invention.

FIG. 7 is an exploded view of one embodiment of a wrist joint of the invention.

FIG. 8 is a perspective view of one embodiment of a double arm cantilever mounting device of the invention.

DETAILED DESCRIPTION OF THE INVENTION

One embodiment of a mounting device 100 is illustrated in FIG. 1 and can be used to display a flat panel television against a wall in a home entertainment center. Mounting device 100 is a cantilever style device that includes a front member such as a front plate 10 for mounting a flat-panel display, electronic device, or any other object suitable for mounting. Opposite front plate 10 is provided a back member or back plate 20 for attaching mounting device 100 to a support structure able to bear the weight of mounting device 100 and mounted object. The support structure is preferably a wall but can be any load-bearing structure. Plastic caps 1 and 2 are provided to cover the top and bottom portions of back plate 20. Caps 1 and 2 conceal screws (not shown) provided to attach back plate 20 to a wall, and will be discussed in more detail with respect to FIG. 2B. A lower arm cap 3 is optionally provided below lower arm 30 to conceal back plate 20 from view.
Mounting device 100 includes articulating joints analogous to a human arm and can be described using similar terminology. For example, a first end of a lower arm 30 is attached perpendicularly to back plate 20 by a shoulder cam 50 to form a shoulder joint that acts as a hinge for rotation of the lower arm about the shoulder joint. Similarly, an elbow joint is formed by an elbow cam 60 where a first end of an upper arm 40 attaches to a second end of lower arm 30. The second end of upper arm 40 connects to front plate 10 at wrist cam 70 to form a wrist joint that allows front plate 10 to pivot side-to-side about an axis of the wrist joint. Each of the shoulder, elbow, and wrist joints has a range of motion that allows mounting device 100 to be adjusted as desired by a user. The shoulder, elbow, and wrist joints rotate in the same plane and may also be referred to as respective first, second, and third joints.
FIGS. 2A-2D illustrate the components of mounting device 100 in greater detail. FIG. 2A shows front plate 10 provided with object mounting holes 11 for mounting objects such as a flat panel display, mounting holes 12 for securing front plate 10 to the wrist joint, and a lip 13 to secure front plate 10 to mounting device 100, as will be discussed later. FIG. 2B illustrates back plate 20 including wall mounting holes 21 and 22, and lower arm mounting holes 23 and 24. The first end of lower arm 30 is placed between holes 23 and 24, and shoulder cam 50 is inserted through hole 23 to secure lower arm 30 to back plate 20. Furthermore, front plate 10 and back plate 20 can be made from steel. In particular, the back plate can be formed of cast steel having a tensile strength of at least 70,000 psi. Lower arm 30 is illustrated in more detail in FIG. 2C, and includes a first end 31 and second end 33 having hollow cylinders. Shoulder cam 50 and elbow cam 60 fit into holes 31 and 33, respectively, as seen in FIG. 3. Hooks 32 allow cap 3 to attach to and cover lower arm 30. FIG. 3D shows the structure of upper arm 40 including a first end 41 and second end 42. The upper and lower arms can be implemented as a truss structure formed of plastic resin such as nylon that provides high strength and low weight.
FIG. 3 is an exploded view of a shoulder joint of the invention including lower arm 30, shoulder cam 50 and back plate 20. As shown in FIG. 3 and 4B, shoulder cam 50 includes a lever 51, pivot pin 52, base 53, pivot shaft 54 and adjustment dial 55. Shoulder cam 50 is placed through mounting holes 22 and 23 of back plate 20 and through hollow cylinder 31 of lower arm 30. The bottom portion of pivot shaft 54 includes a threaded portion which screws into adjustment dial 55. The bottommost portion of shaft 54 is secured into back plate 20 by hole 22. Adjustment dial 55 is attached to shaft 54 and is provided between the bottom of first end 31 and mounting hole 22. The top portion of pivot shaft 54 includes a hole for pivot pin 52. Base 53 is provided with a hole for sliding over the top of pivot shaft 54. Lever 51 rests above base 53 and includes a cavity for pivot shaft 54 to protrude into. In the assembled shoulder cam 50, pivot pin 52 is provided through corresponding holes in lever 51 and the hole of pivot shaft 54. Pivot pin 52 secures lever 51, base 53 and shaft 54 together.
FIG. 4A shows the adjustment position of the cam of the present invention. When lever 51 is unlocked and set vertically so as to be parallel to pivot shaft 54, enough tension is released in the shoulder joint so that adjustment dial 55 can be rotated to increase or decrease the tension between lower arm 30 and back plate 20 at the shoulder joint. The user simply pushes the lever up and down to move from the locked position to the unlocked adjustment position. In this manner, lower arm 30 and back plate 20 can rotate about the shoulder joint. Furthermore, adjustment dial 55 can be rotated to either allow or not allow rotation of the shoulder joint. The joint is rotated by the user rotating lower arm 30 about the shoulder joint. Once set at a desired position, the lever is pushed down to increase the tension and lock lower arm 30 in place. However, when lever 51 is set horizontally to the locked position, the tension of the shoulder joint is strong enough to prevent rotation of adjustment dial 55. Furthermore, lever 51 in the locked position can prevent rotation of lower arm 30 and back plate 20 about the shoulder joint. Thus, the use of lever 51 and adjustment dial 55 allows a user to adjust the position and tension of the shoulder joint with an economy of motion and without the need for tools. As described in more detail below, the levers of the elbow cam and wrist cam operate in a similar manner to provide an adjustment position and locked position.
FIG. 5A provides a side view of mounting device 100 with a focus on the connection of lower arm 30 to upper arm 40 at the elbow joint by elbow cam 60. Similar to shoulder cam 50, elbow cam 60 includes a lever 61, pivot pin 62, base 63 and fastening shaft 65. Elbow cam 60 further includes a tension pin 64 and a base cap 66. Fastening shaft 65 is inserted into first end 41 of upper arm 40 and through second end 33 of lower arm 30. Fastening shaft 65 is secured to the bottom of lower arm 30 by a base cap 66. Tension pin 64 is screwed into the top of fastening shaft 65 and includes a hole for pivot pin 62. The operation of elbow cam 60 is similar to that of shoulder cam 50. For example, when lever 61 is provided in a horizontal locked position, the downward force of lever 61 locks the position of lower arm 30 and upper arm 40 in place to prevent movement of the arms and rotation of the elbow joint. However, when lever 61 is set to the vertical adjustment position, the tension between lever 61 and base 63 is relieved such that a user can operatively rotate upper arm 40 relative to lower arm 30 about the elbow joint. FIG. 5C provides a more detailed view of elbow cam 60.
FIG. 5C illustrates a sectional view of the elbow joint. As discussed above, fastening shaft 65 is provided in the hollow end cylinders of upper arm 40 and lower arm 30. Furthermore, tension pin 64 is inserted through pivot pin 62, base 63 and the top of fastening shaft 65 to secure those elements together. Tension pin 64 can be a threaded screw and is screwed into fastening shaft 65 to increase or decrease the elbow tension. After lever 61 is pushed and unlocked at an adjustment position that reduces the tension in the elbow joint, a user is then able to rotate base 63 and lever 61 to either loosen or tighten tension pin 64 to adjust the tension of the elbow joint further. When lever 61 is in the locked position, tension pin 64 does not rotate. If the elbow joint is unlocked or loosened, the user is able to rotate and reposition lower arm 30 and upper arm 40 with respect to each other about the elbow joint. When tightened by rotating base 63 and locked by pushing down on lever 61, the angle of the arms is set in place. Thus, after unlocking the elbow cam 60, lever 61 and base 63 can be rotated to adjust the tension of cam 60 to allow lower arm 30 and upper arm 40 to move relative to each other as desired by a user.
The wrist joint is now described. FIG. 6A is a side view of the wrist joint including wrist cam 70, front plate 10, and tilt links 75 and 79 connecting thereto. Wrist cam 70 includes a lever 71, base 73, pivot shaft 76, top pivot 77 and bottom pivot 78. Front plate 10 is connected to wrist cam 70 via a mounting plate 14 (see FIG. 7) and tilt links 75 and 79.
As shown in the exploded schematic view of FIG. 7, each of the tilt links 75 and 79 is inserted through corresponding holes of mounting plate 14 to attach wrist cam 70 to front plate 10. Mounting plate 14 is then secured to lip 13 and mounting holes 12 of front plate 10. Tilt links 75 and 79 allow the front plate to adjustably pivot up and down along an axis perpendicular to the wrist joint. Top tilt link 75 is connected to wrist cam 70 via top pivot 77. Bottom tilt link 79 is connected to bottom pivot 78 at a bottom end of shaft 76. Furthermore, pivot shaft 76 includes a lower threaded portion screwed into bottom pivot 78.
FIGS. 6B and 6C are side and exploded views of wrist cam 70 including the components of a lever 71, pivot pin 72, base 73, top pivot 77 and pivot shaft 76. Pivot shaft 76 is inserted into the top of second end 42 and secured at the bottom of second end 42 by bottom pivot 78 (FIG. 6D). Bottom pivot 78 is provided just below upper arm 40. The top of pivot shaft 76 includes a hole for pivot pin 72. Base 73 and top pivot 77 are provided with a central hole for sliding over the top of pivot shaft 76. Top pivot 77 is provided below the hole of shaft 76. Lever 71 rests above base 73 and includes a cavity for pivot shaft 76 to protrude into. In the assembled wrist cam 70, pivot pin 72 is provided through corresponding holes in lever 71 and the hole of pivot shaft 76 to secure the lever 71, base 73, pivot pin 72 and shaft 76 together.
The operation of wrist cam 70 is somewhat similar to shoulder cam 50 and elbow cam 60. When lever 71 is provided in a horizontal locked position, the downward force of lever 71 locks the position of pivots 77 and 78 to prevent side-to-side movement of front plate 10 about an axis of the wrist joint. However, when lever 71 is pushed to the vertical adjustment position by a user, the tension between lever 71 and pivot shaft 76 is relieved such that a user can then rotate lever 71 and base 73 to decrease the wrist joint tension to thereby rotate front plate 10 to a desired position.
FIG. 6D illustrates a sectional view of the wrist joint. As discussed above, pivot shaft 76 is provided in second hollow cylinder end 42 and the bottom portion of pivot shaft 76 has a threaded portion which screws into bottom pivot 78. When lever 71 is unlocked in the vertical position, a user is able to rotate base 73, lever 71 and pivot shaft 76, to either loosen or tighten the tension of the wrist joint. If the wrist joint is unlocked or loosened, top link 75 and bottom link 79 can move such that the user is able to rotate and reposition front plate 10 with respect to upper arm 40 about the wrist joint. When tightened and locked by pushing the lever in the appropriate direction, the angle between front plate 10 and upper arm 40 is locked in place. Shaft 76 is unable to rotate when locked. Thus, after unlocking wrist cam 70, lever 71 and base 73 can be rotated to adjust the tension of wrist cam 70 to allow front plate 10 to move side-to-side relative to upper arm 40. Moreover, the grip-like hollow space shown in pivot 77 of FIG. 6B indicates the range of motion of top tilt link 75 along the axis of the rotation perpendicular to the wrist joint.
The levers and bases of the cams, as well as pivots 77 and 78, are preferably formed from plastic resin while pivot shaft 54, fastening shaft 65, and pivot shaft 76 are preferably formed of high carbon steel. Furthermore, pivot shaft 54, fastening shaft 65 and pivot shaft 76 should have a yield strength of at least 100,000 psi. The tilt links are preferably formed from plastic resins and steel.
An alternative embodiment of the invention is now described with reference to FIG. 8. Mounting device 200 of FIG. 8 is a double arm cantilever mounting device having a pair of wrist, elbow and shoulder joints. In particular, mounting device 200 includes a back plate 220 and first and second front plates 210 and 211. First and second shoulder cams 250 and 251 connect first and second lower arms 230 and 231 to back plate 220. A cap 201 is provided to cover the bottom of the lower arms. First and second upper arms 240 and 241 are provided and connect to first and second lower arms 230 and 231 by first and second elbow cams 260 and 261. First and second front plates 210 and 211 are connected to first and second upper arms 240 and 241 by first and second wrist cams 270 and 271. The double arm mounting device 200 allows a wide range of adjustment for mounting objects of increased size/weight.
The particular embodiments of the invention described in this document should be considered illustrative, rather than restrictive. Modification to the described embodiments may be made without departing from the spirit of the invention as defined by the following claims and their equivalents.

Claims

1. A cantilever mounting device comprising:

a front member on which an object is mounted;

a back member for attachment to a load-bearing surface;

a first arm connected to said back member to form a rotatable first joint;

a second arm connected to said first arm to form a rotatable second joint;

said front member connected to said second arm to form a rotatable third joint;

wherein said first joint includes a first cam including a first lever and a first shaft for connecting said back member to said first arm;

wherein said first lever is set in a first locked position and a first adjustment position;

wherein said first cam allows rotation about an axis of the first joint when said first lever is set to said first adjustment position, and said first cam does not allow rotation about the axis of the first joint when said first lever is set to said first locked position.

2. The cantilever mounting device of claim 1, wherein

said first cam includes an adjustment dial; and

said first cam allows rotation of said adjustment dial when said first lever is set to said first adjustment position, and said first cam does not allow rotation of said adjustment dial when said first lever is set to said first locked position.

3. The cantilever mounting device of claim 2, wherein

the rotation of said adjustment dial increases or decreases a tension of the first joint.

4. The cantilever mounting device of claim 1, wherein

said first cam includes a first base, a first pivot pin, and an adjustment dial;

wherein said first pivot pin is inserted into said first lever and said first shaft to secure said first lever, said first base, and said first pivot pin to a first end of said first shaft;

wherein said adjustment dial is connected to a second end of said first shaft.

5. The cantilever mounting device of claim 1, wherein

the first locked position of said first lever is provided perpendicular to said first shaft, and the first adjustment position of said first lever is provided parallel to said first shaft.

6. The cantilever mounting device of claim 1, wherein

said second joint includes a second cam including a second lever, a second shaft, and a tension pin for connecting said first arm to said second arm;

wherein said second lever is set in a second locked position and a second adjustment position;

wherein said second cam allows rotation about an axis of the second joint when said second lever is set to said second adjustment position and said second cam does not allow rotation about the axis of the second joint when said second lever is set to said second locked position.

7. The cantilever mounting device of claim 6, wherein

said second cam allows rotation of said tension pin when said second lever is set to said second adjustment position, and said second cam does not allow rotation of said tension pin when said second lever is set to said second locked position.

8. The cantilever mounting device of claim 6, wherein

the rotation of said tension pin increases or decreases a tension of the second joint.

9. The cantilever mounting device of claim 6, wherein

said second cam includes a second base and a second pivot pin;

wherein said tension pin is inserted into said second shaft;

wherein said second pivot pin is inserted into said second lever and said tension pin to secure said second lever, said second base, said second pivot pin and said tension pin to said second shaft.

10. The cantilever mounting device of claim 6, wherein

said tension pin is a screw.

11. A cantilever mounting device comprising:

a front member on which an object is mounted;

a back member for attachment to a load-bearing surface;

a first arm connected to said back member to form a rotatable first joint;

a second arm connected to said first arm to form a rotatable second joint;

said front member connected to said second arm to form a rotatable third joint;

said third joint includes a third cam including a third lever and a third shaft;

wherein said third lever is set in a locked position and an adjustment position,

wherein said third cam allows rotation about the axis of the third joint when said third lever is set to said adjustment position, and said third cam does not allow rotation about an axis of the third joint when said third lever is set to said locked position.

12. The cantilever mounting device of claim 11, wherein

said third cam allows rotation of said third shaft when said third lever is set to said adjustment position, and said third cam does not allow rotation of said third shaft when said third lever is set to said locked position.

13. The cantilever mounting device of claim 11, wherein

the rotation of said third shaft increases or decreases a tension of the third joint.

14. The cantilever mounting device of claim 11, wherein

said third cam includes a third base, a third pivot pin, a top pivot, and a bottom pivot;

wherein said third pivot pin is inserted into said third lever and said third shaft to secure said third lever, said third base, and said top pivot pin to a first end of said third shaft;

wherein said bottom pivot is connected to a second end of said third shaft.

15. The cantilever mounting device of claim 11, further comprising:

a tilt link connected to said top pivot and said bottom pivot;

wherein said tilt link connects said third cam to said front member;

wherein said tilt link provides rotation about an axis perpendicular to the axis of said third joint.

16. A method of adjusting a cantilever mounting device comprising the steps of:

applying force to a first lever of a first cam for reducing a tension of a first joint and for setting said first lever to a first adjustment position;

rotating a first arm relative to a back member about the first joint when said first lever is in the first adjustment position;

applying force to said first lever for increasing the tension of the first joint and for setting said first lever to a first locked position such that said first arm is locked in place relative to said back member.

17. The method of adjusting the cantilever mounting device of claim 16, further comprising the steps of:

rotating an adjustment dial of said first cam to reduce the tension of the first joint when said first lever is set to the first adjustment position.

18. The method of adjusting the cantilever mounting device of claim 16, further comprising the steps of:

applying force to a second lever of a second cam for reducing a tension of a second joint and for setting said second lever to a second adjustment position;

rotating a second arm relative to said first arm about the second joint when said second lever is in the second adjustment position;

applying force to said second lever for increasing the tension of the second joint and for setting said second lever to a second locked position such that the second arm is locked in place relative to said first arm.

19. The method of adjusting the cantilever mounting device of claim 16, further comprising the steps of:

applying force to a third lever of a third cam for reducing a tension of a third joint and for setting said third lever to a third adjustment position;

rotating a front member relative to said second arm about the third joint when said third lever is in the third adjustment position;

applying force to said third lever for increasing the tension of the third joint and for setting said third lever to a third locked position such that the front member is locked in place relative to said second arm.

20. The method of adjusting the cantilever mounting device of claim 19, further comprising:

tilting the front member about an axis perpendicular to the third joint.