The present invention relates to a monitor support arm primarily for a flat screen display panel such as a computer screen or LCD television.
Monitor support arms for supporting flat screen computer monitors are known and enable a user to adjust a monitor mounted to the arm over a range of vertical and horizontal angles so that it can be moved into a desired working position to suit. The ability to move a monitor easily into any desired position is important as it minimises eye strain and may alleviate or prevent back or other bodily pain which may arise as a result of sitting at an improperly positioned workstation over a period of time.
A monitor support generally has an elongate link arm pivotally attached to a support element at a first end which cooperates with a support post upstanding from a desk or other surface. Alternatively, the support element may be attached to a vertical surface such as a wall or partition. A mounting plate that complies with the VESA screen mounting standards is attached to the opposite or second end of the arm via a universal or pivot joint for attachment of a computer monitor in the usual way. Alternatively, the arm may have a secondary limb extending from and pivotally attached to its free end opposite the support element, in which case the mounting plate is attached to the remote end of the secondary limb so that the screen may be manipulated into a wide range of different positions and orientations.
It is known to provide a monitor support arm with a four bar or parallelogram linkage configuration to maintain a constant orientation of the computer screen as the arm pivots in a vertical plane to alter its height. It is also known to provide a gas strut to support the load of the monitor and the weight of the four bar linkage assembly and facilitate the easy adjustment of the monitor. The gas strut extends from and is pivotally attached to the support element and its other end is pivotally connected to the remote end, or close to the remote end, of an elongate link arm that also extends from and is pivotally attached to the support element spaced above the point at which the gas arm is pivotally connected to the support element. The distance between the point at which the gas arm is pivotally connected to the support element and the point at which the elongate link arm is pivotally connected to the support element is adjustable to compensate for monitors of different weights supported on the end of the arm. As the distance between the pivots decreases and the angle between the gas arm and the elongate link arm reduces, the load provided by the gas arm decreases to assist in counterbalancing a lighter weight monitor because a greater component of the force provided by the gas strut is acting along the link arm as opposed to in a vertical direction. However, if the distance between the pivots increases and the angle between the gas arm and the elongate link arm increases, the load provided by the gas arm increases to counterbalance a heavier weight monitor, because a greater component of the force provided by the gas strut is acting in a vertical direction than in a direction along the link arm. When a monitor has been attached to the arm and the counterbalance adjustment has been made, no clamping mechanism is required to hold the screen in a desired position. The monitor can therefore be raised or lowered to move it into the desired position without having to release a clamp and carry the entire weight of the monitor during the adjustment. It will be appreciated that after the initial set-up, no further load adjustment of the gas strut is required unless the monitor is replaced for one of a different weight.
A typical four bar linkage assembly comprises a primary support bracket at one end which remains stationary and is attached to a support post or other supporting surface and, a secondary support bracket at the opposite end for movement in a vertical plane to adjust the height of a monitor attached to it. The primary and secondary support brackets are coupled together by a first or upper link arm which is pivotally attached at one end to the primary support bracket and at the other end to the secondary support bracket. Similarly, a second or lower link arm is pivotally attached at one end to the primary support bracket and at the other end to the secondary support bracket. The pivotal connection of the upper and lower link arms to each of the primary and secondary support brackets are spaced from each other in the vertical direction so that the upper and lower link arms are spaced from but parallel to each other. As the upper and lower link arms pivot about their respective pivots on the primary support bracket to lower or raise the secondary support bracket, they also pivot about their pivots on the secondary support bracket so that the secondary support bracket maintains the same parallel orientation or geometry as the primary support bracket. As has been explained above, a gas strut extends between and is pivotally connected to the primary support bracket and to the upper link arm close to or at its point of connection to the secondary support bracket to counterbalance the support arm and prevent it from dropping under the weight of the monitor. The pivotal connection of the gas strut to the primary support element can be moved closer to, or away from, the pivotal point of attachment of the upper link arm to the primary support element, to alter the counterbalancing load provided by the gas strut.
A disadvantage with the conventional four bar linkage arrangement is that they are generally unattractive and complicated and present a number of areas where fingers could become trapped or pinched during height adjustment.
The present invention seeks to provide an improved monitor support arm which overcomes or substantially alleviates the disadvantages mentioned above, which reduces the total number and overall weight of the components of the device and improves its appearance.
A monitor support according to the present invention comprises a primary support member for attachment to a post, wall or other mounting surface, a rigid link arm extending from the primary support member for rotation relative to the primary support member about a first pivot axis in a vertical plane, a secondary support member attached to the free end of the link arm for rotation of the secondary support member relative to the link arm about a second pivot axis parallel to the first pivot axis and, a flexible control element extending between the primary and secondary support members spaced from the first and second pivot axes respectively, the monitor support being configured so that the control element causes the secondary support member to rotate relative to the link arm about the second pivot axis as the link arm rotates relative to the primary support member about the first pivot axis so as to maintain the same relative orientation of the primary and secondary support members.
It will be appreciated that the monitor support arm of the present invention employs the principles of a four-bar linkage assembly but may do so without the use of multiple pivotal connections between the linkages and the supporting elements thereby providing a simple device with a more aesthetic appearance and smooth adjustment.
In a preferred embodiment, the support comprises a pair of parallel link arms, both link arms being mounted to the primary and secondary support members for rotation about the first and second axes respectively, and so as to be spaced from each other in an axial direction.
Preferably, the primary and secondary support members extend between and space the parallel link arms from each other in said axial direction.
The parallel link arms may be configured so that the flexible control element is disposed in the space between said parallel arms and the parallel link arms at least partially conceal said flexible control element.
The parallel link arms may advantageously include upstanding walls extending into the space between said parallel link arms to provide support for the control element extending between the primary and secondary support members.
In one embodiment, a pair of flexible control elements extend between the primary and secondary support members, said flexible control elements being spaced from each other in an axial direction so that each control element lies adjacent to one of said parallel link arms.
The control element is preferably spaced above a line extending between the first and second pivot axes and, a second flexible control element extends between the primary and secondary support members spaced below a line extending between the first and second pivot axes.
In another embodiment the monitor support comprises a first pair of flexible control elements spaced above a line extending between the first and second pivot axes and, a second pair of flexible control elements extending between the primary and secondary support members spaced below a line extending between the first and second pivot axes.
In a particularly preferred embodiment, the flexible control element is endless and extends around both the primary and secondary support members.
The primary support member may include a control element guide to receive and guide the cable around the primary support member. The control element guide can be at least partially arcuate in shape so that the control element follows a curved path around the primary support member.
Similarly, the secondary support member may include a control element guide to receive and guide the control element around the secondary support member. The control element guide may be at least partially arcuate in shape so that the control element follows a curved path around the secondary support member.
In the most preferred embodiment, the control element is looped around the primary and secondary support members and comprises at least one upper run that extends between the primary and secondary support members and at least one lower run that extends between the primary and secondary support members.
The primary support member may be configured such that the lower run intersects a vertical plane extending through the first pivot axis at a distance below the first pivot axis and the upper run intersects said vertical plane at a distance above said first pivot axis. Similarly, the secondary support member may be configured so that the lower run intersects a vertical plane extending through the second pivot axis at a distance below the second pivot axis and the upper run intersects said vertical plane at a distance above the second pivot axis.
Preferably, the control element loop is elongated to form two curved ends, an intermediate section between said ends passing around the primary support member with the two curved ends hooked over the secondary support member so that the control element has two upper and two lower runs extending between the primary and secondary support elements.
In one embodiment the support may include a control element adjustment mechanism for tensioning the control element which can be mounted on the primary support member. The primary support member preferably includes a recess extending substantially at right angles to the direction of the run of the control element so that the control element bridges the mouth of the recess as it extends over the primary support element.
The tension adjustment mechanism preferably includes a tensioning member which can be drawn into the recess against the control member, once a control element has been positioned so as to extend over the mouth of the recess, to pull the control element into the recess to tension the control element.
The tension adjustment mechanism may include a threaded rod in engagement with the primary support element that extends beyond the mouth of the recess, the tensioning member being threadingly engaged with the rod so that a control element extending over the mouth of the recess is engaged by the tensioning member as the rod is rotated and the tensioning member is drawn into the recess against the control member.
In a preferred embodiment, a gas strut extends between the primary and secondary support elements. One end of the gas strut is preferably coupled to a shaft extending coaxial with the first pivot axis on the primary support member. The monitor support may advantageously include a hook member attached to an end of the gas strut to connect the gas strut to the shaft.
One end of the gas strut is preferably pivotally attached to a load adjustment member coupled to the secondary support member and the load adjustment member is configured to enable said end of the gas strut coupled to it to be moved towards or away from the second pivot axis to adjust the load provided by the gas strut.
In a preferred embodiment, a threaded rod extends through the secondary support member and into the load adjustment member so that rotation of said threaded rod moves the end of the gas strut pivotally coupled to the load adjustment member towards or away from the second pivot axis.
The link arm and the secondary support element advantageously includes cooperating members to limit the rotation of the arm in said vertical plane to within a predetermined angle.
In one embodiment, the cooperating members comprise a boss on the secondary support element which locates in an arcuately shaped guide groove in the link arm so that rotation of the arm is limited by the extent of the guide groove.
The secondary support element may include a mounting shaft for the pivotal attachment of a secondary arm thereto, the monitor being attachable to the free end of the secondary arm.
In a preferred embodiment, the flexible control element is a cable. Alternatively, the flexible control element could be a belt.
Embodiments of the invention will now be described, by way of example only, and with reference to the accompanying drawings, in which:
Referring now to the drawings, there is shown in
The second section 3 comprises a secondary arm 8 pivotally connected at one end to the secondary support member 7 and having a flat screen mounting plate 9 attached to its other end remote from the secondary support member 7 by a universal or similar type pivot joint 10.
It will be appreciated that the secondary arm 8 is not an essential part of the invention and the flat screen mounting plate 9 could be attached directly to the secondary support member 7 via a pivot or universal joint 10, instead. The present invention is primarily concerned with the first section 2, illustrated more closely in
The primary support member 4 is shown more clearly in
The top wall potion 16 has a pair of parallel spaced arcuately shaped guide grooves 18 formed therein adjacent to each of the parallel walls 12, 13 to receive and guide a control element which, in the preferred embodiment, is a cable 25 (see
The outer surface of each wall 12, 13 provides a mounting surface for link arms 6 which are coupled to the outside of each wall 12, 13 using a fastening member such as a bolt (not shown) that extends through an aperture 26 in each wall 12, 13 so as to pivotally mount the arms 6 for rotation relative to the primary support member 4 about a first pivot axis 27 coaxial with the aperture 26 in each wall 12, 13. It will be appreciated that both link arms 6 are pivotally mounted to each wall 12,13 of the primary support member 4 for rotation about the same pivot axis 27 and are spaced from each other by the distance between the outer surface of each wall 12, 13.
The secondary support member 7 is illustrated in
Each spaced parallel wall 33, 34 has an aperture 41 therein to receive and pivotally attach the opposite end of each of the link arms 6 to the outer surface of each wall 33, 34, using a bolt (not shown) that extends through both the walls 33, 34 and both the link arms 6, so that the secondary support member 7 and the link arms 6 pivot together with respect to the first axis 27 and the secondary support member 7 can pivot relative to the link arms about a second axis 42 extending through the aperture 41. It will be appreciated that both link arms 6 are mounted to the secondary support member 7 for rotation about the same pivot axis 42.
The secondary support member 7 may include a cable guide member 71 that attaches to the shaft portion 30.
The spacing between the walls 12, 13 of the primary support member 4 and the walls 33,34 of the secondary support member 7 is substantially the same so that, when the ends of each of the link arms 6 are pivotally attached to each wall 12,13,33,34 of the primary and secondary support members 4, 7, they are parallel to each other and the grooves 18,20,36,38 in the primary and secondary support members 4,7 are in alignment so that the control cable 25 extends between the primary and secondary support members 4,7 parallel to the link arms 6. The link arms 6 extend in a vertical direction so that the control cable 25 is disposed between them and is at least partially concealed by the link arms 6, at least when the monitor support is viewed from the side, in the direction as illustrated in
The gas strut 33a extends between the primary and secondary support members 4,7 and is also concealed by the link arms 6. One end of the gas strut 33a which is coupled to the primary support member 4 is provided with a hooked element 33b (see
It will be appreciated that the gas strut acts applies a force to the secondary support member 7 which would cause it to rotate about the second pivot axis 42 (in an anti-clockwise direction as shown in
In the preferred, and illustrated, embodiment, the control cable 25 is endless extends between and around both the primary and secondary support elements 4,7 and is configured so as to cause the secondary support element 7 to rotate relative to the link arms 6 about the second pivot axis 42 as the link arms 6 rotate relative to the primary support element 4 about the first pivot axis 27 so as to maintain the same relative orientation or geometry between the primary and secondary support elements 4,7. Effectively, the control cable 25 acts together with the link arms 6 and the primary and secondary support members 4,7 as a parallelogram linkage assembly.
A portion of the cable 25 is shown in dashed lines in
The first and second ends 25b,25d of the cable loop 25 are received in and meet within the recess 40 formed in the shaft portion 30. The lower cable run 25c passes alongside either side of the shaft portion 30 and into the guide grooves 38 in each lower surface of the secondary support element 7 and then spans the space between the primary and secondary support elements 4,7 substantially unsupported, although a shoulder or supporting wall 60 may be formed on the inner surface of each link arm 6 which extends into the space between the link arms 6 and at least part of the upper and/or lower run may lie over or at least contact the shoulder 60 so as to be partially supported by it. When the lower cable run 25c reaches the primary support element 4 it passes into the mouth 21 of the lower guide grooves 18 formed in the ridges 20 on the inner wall surface and bridges the break in the ridges 20 before passing up through the aperture 19 between the sleeve 5 and the mounting portion 11 and over the top wall 16 before the upper cable run 25a spans the gap between the primary and secondary support elements 4,7 before passing into the upper guide grooves 36 in the upper wall 35 of the secondary support member 7 before being hooked over the shaft portion 30 and retained in the recess 40 adjacent to the first end 25b.
It will therefore be appreciated that there two upper parallel cable runs 25a and two lower parallel cable runs 25c extending between the primary and secondary support elements 4,7. It will also be appreciated that the cable 25 meets the primary and secondary support elements 4,7 at a distance from the first and second pivot axes 27,42.
The primary support element 4 includes a cable tensioning mechanism 50 to draw the cable 25 tightly against the primary and secondary support elements 4,7 and prevent any slippage or play between components. It will be appreciated that the cable tensioning mechanism 50 could also, or alternatively, be provided on the secondary support element 7 instead of the primary support element 4.
As mentioned above, a threaded rod or bolt 24 extends through the aperture 23 in the top wall 16 of the mounting portion 11 of the primary support element 4 and beyond the mouth 22 of the break between the ridges 20 formed on the inner surface of the walls 12, 13. A cylindrical cable capture member 51, illustrated in
As shown in
At least one of the walls 33, 34 of the secondary support member 7 is provided with an upstanding boss 52 (see
It will be appreciated that, when the height of a monitor attached to the secondary support element 7 is adjusted, the link arms 6 rotate about the first pivot axis 27 and the secondary support element 7 rotates about the second pivot axis 42 as the cable 25 extending tightly around the primary and secondary support elements 4,7 maintains the relative orientation of the primary and secondary support elements 4,7 during said adjustment.
As mentioned above, in a preferred embodiment, the control element or cable is endless and extends between and around the primary and secondary support members 4,7. However, in an alternative embodiment, the control element need not be endless and the control element can be pivotally attached at each end to the primary and secondary support members at further pivot points spaced from the first and second pivot points attaching the link arms to the primary and secondary support members. A single or dual upper cable run extending between the primary and secondary support elements 4,7 may be employed. However, it is preferable to provide a second single or dual lower cable run extending between the primary and secondary support elements spaced from the first single or dual cable run in a vertical direction on the opposite side of a line extending between the first and second pivot axes. The second single or dual cable run prevents the secondary support member 5, and a monitor attached thereto, from being rotated so that it points in an upward direction which would not be prevented by the upper cable run—the upper cable run would go slack. However, it will be appreciated that the lower cable run is not essential as the parallelogram operation of the support arm works adequately between the link arm 6 and the upper cable run.
It will be appreciated that a single endless cable is preferred as it avoids additional pivotal connections of the cable to the primary and secondary support members requiring additional components and connections which are subjected to unwanted play between them and increased wear over prolonged use. The preferred embodiment of the present invention provides a monitor support in which free play and wear between components is minimised and which assembly is simplified. The resulting monitor support has a smoother, more fluid movement during height adjustment.
Many modifications and variations of the invention falling within the terms of the following claims will be apparent to those skilled in the art and the foregoing description should be regarded as a description of the preferred embodiments only.
Number | Date | Country | Kind |
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0607484.3 | Apr 2006 | GB | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP07/53644 | 4/13/2007 | WO | 00 | 9/23/2009 |