U.S. patent application number 09/902430 was filed with the patent office on 2001-11-01 for tilt adjustable keyboard support.
This patent application is currently assigned to Work-Rite Ergonomic Accessories, Inc.. Invention is credited to Timm, Derek.
Application Number | 20010035482 09/902430 |
Document ID | / |
Family ID | 22628065 |
Filed Date | 2001-11-01 |
United States Patent
Application |
20010035482 |
Kind Code |
A1 |
Timm, Derek |
November 1, 2001 |
Tilt adjustable keyboard support
Abstract
A keyboard supporting member has a generally planar keyboard
support surface whose orientation is adjustable. A keyboard
engaging member defines aligned incline defining slots on opposite
sides of a center section. A second, workstation engaging member
allows the user to move the keyboard back and forth with respect to
a workstation. This allows the user to move the keyboard between a
storage position and an in use position. A linkage interconnects
the two members for adjusting a relative position of the keyboard
engaging member with respect to the workstation engaging member
thereby allowing the keyboard position and orientation to be
controlled by the user. The linkage includes a first elongated
member having one end rotatably mounted to the workstation engaging
member which has an arcuate slot at one end spaced from the end
that is connected to the workstation engaging member. The linkage
also includes a second elongated member having one end rotatably
mounted to the workstation engaging member and including a hole in
an end spaced from the end that is connected to the workstation
engaging member. A connector pass through the arcuate slot in the
first elongated member, the aligned incline defining slots of the
keyboard engaging member, the hole passing through the second
elongated member, and wedge shaped blocks for adjusting frictional
engagement between said first and second elongated members to
maintain an orientation between the keyboard engaging member and
the workstation.
Inventors: |
Timm, Derek; (Windsor,
CA) |
Correspondence
Address: |
WATTS, HOFFMANN, FISHER & HEINKE CO., L.P.A.
Ste. 1750
1100 Superior Ave.
Cleveland
OH
44114
US
|
Assignee: |
Work-Rite Ergonomic Accessories,
Inc.
|
Family ID: |
22628065 |
Appl. No.: |
09/902430 |
Filed: |
July 10, 2001 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
09902430 |
Jul 10, 2001 |
|
|
|
09172522 |
Oct 14, 1998 |
|
|
|
Current U.S.
Class: |
248/284.1 |
Current CPC
Class: |
A47B 2021/0342 20130101;
A47B 2021/0321 20130101; Y10S 248/918 20130101; A47B 2021/0335
20130101; A47B 21/0314 20130101 |
Class at
Publication: |
248/284.1 |
International
Class: |
E04G 003/00 |
Claims
I claim:
1. Apparatus for movably supporting a keyboard with respect to a
workstation comprising: a) a keyboard engaging member having a
generally planar keyboard support surface whose orientation is
controlled to control an orientation of the keyboard with respect
to a work surface of said workstation; said keyboard engaging
member comprising two parallel side pieces spaced apart by a center
section, said side pieces defining aligned slots on opposite sides
of the center section; b) a workstation engaging member that
supports the keyboard for back and forth movement with respect to
the workstation to allow the keyboard to be stored in a storage
position and be moved to an in use position; and c) a linkage for
adjusting a relative position of the keyboard engaging member with
respect to the workstation engaging member and thereby adjusting a
keyboard position with respect to the workstation comprising: i) a
first elongated member having one end rotatably mounted to the
workstation engaging member and including a body portion that
extends away from the workstation engaging member at a controlled
angle; said first elongated member including an arcuate slot at an
end spaced from the end that is rotatably mounted to the
workstation engaging member; ii) a second elongated member having
one end rotatably mounted to the workstation engaging member and
including a body portion that extends away from the workstation
engaging member at a controlled angle, said second elongated member
including a hole at an end spaced from the end that is rotatably
mounted to the workstation engaging member; iii) a connector
passing through said arcuate slot in said first elongated member,
said aligned slots of said keyboard engaging member, and the hole
passing through said second elongated member; and iv) a wedge
carried by the connector for adjusting frictional engagement
between said first and second elongated members to maintain an
orientation between the keyboard engaging member and the
workstation.
2. The apparatus of claim 1 wherein said linkage further comprises
a second set of first and second elongated members and a second
wedge.
3. The apparatus of claim 1 wherein said connector farther
comprises a knob disposed at one end for adjusting a tilt angle of
the keyboard.
4. The apparatus of claim 1 wherein said aligned slots in said
keyboard engaging member are arcuate and are disposed along
inclined segments of the two parallel side pieces and said wedge
comprises a slide which slideably engages one of said arcuate slots
along said inclined segment and a face of said wedge engages said
inclined segment such that movement of said wedge along said
inclined segment changes the fictional engagement between said
first and second elongated members.
5. The apparatus of claim 4 wherein said linkage further comprises
a second set of first and second elongated members and a second
wedge and said connector further comprises a knob and one of said
wedges further comprises a spring bearing surface; said apparatus
further comprising and a spring trapped between said knob and said
spring bearing surface to maintain a level of pressure between said
wedges and said inclined segments.
6. The apparatus of claim 4 wherein said wedge is adapted such that
downward pressure on said keyboard engaging member causes said
wedge to increase the frictional engagement between said first and
second elongated member.
7. The apparatus of claim 4 wherein the linkage and the keyboard
engaging member are pivotally coupled together and wherein said
wedge is adapted such that an upward rotation of said keyboard
engaging member with respect to the linkage causes said wedge to
decrease fictional engagement between said first and second
elongated members allowing the linkage to be reoriented thereby
adjusting the height of the keyboard.
8. The apparatus of claim 4 wherein said knob threadingly engages
said connector and rotation of aid knob causes movement of said
wedges in said arcuate slot of said keyboard engaging member to
adjust an orientation of said keyboard support with respect to
horizontal.
9. The apparatus of claim 1 wherein said workstation engaging
member comprises: i) at least one horizontally oriented track in
which said linkage may ride; ii) a horizontally oriented
progressive ball bearing slide movable along the length of the
track; iii) a keyboard support carriage supported by the ball
bearing slide and movable along the slide.
10. The apparatus of claim 1 wherein said workstation engaging
member further comprises a counterbalance spring which assists in
upward movement of said keyboard support.
11. A method of supporting a keyboard in a position relative to a
work surface comprising the steps of: a) providing a generally
planar keyboard support; b) pivotally connecting the generally
planar keyboard support to first and second elongated linkage arms;
c) attaching opposite ends of the first and second linkage arms to
a work surface defining workstation; d) adjusting the height of the
keyboard support with respect to the work surface by changing an
orientation of the linkage arms with respect to the workstation; e)
adjusting the orientation of the keyboard support with respect to
the work surface by adjusting the orientation of the keyboard
support with respect to the linkage arms; and f) limiting relative
rotation of the arms with respect to the planar keyboard support
and the workstation to fix the keyboard support at a height and at
an orientation with respect to the work surface.
12. The method of claim 11 wherein the step of attaching the first
and second linkage arms to a work surface defining workstation
comprises the steps of: a) attaching two spaced apart horizontally
oriented tracks which define a linear travel path to the
workstation; b) attaching the first and second elongated linkage
arms to a carriage, and c) supporting the carriage for movement
along the two spaced apart horizontally oriented tracks by mounting
a progressive ball bearing slide in each of the two tracks to
support opposite sides of the carriage.
13. The method of claim 12 wherein the step of attaching the first
and second linkage arms is performed by pivotally supported the
first arm at a first side location of the carriage and pivotally
supporting the second arm at a second, spaced side location of the
carriage so that the first and second arms pivot independently from
each other during height and orientation adjustment of the keyboard
with respect to the workstation.
14. The method of claim 11 wherein a friction surface of the
keyboard support overlaps a corresponding friction surface of one
of the first and second linkage arms and the step of limiting
relative rotation is performed by biasing the friction surface
against the corresponding friction surface.
15. Apparatus for movably supporting a keyboard with respect to a
workstation comprising: a) a keyboard support member having a
generally planar keyboard support surface whose orientation is
controlled to control an orientation of the keyboard with respect
to a work surface of said workstation; said keyboard support member
comprising two side pieces spaced apart by a center section, said
side pieces defining aligned slots on opposite sides of the center
section; b) a workstation engaging member that supports the
keyboard for back and forth movement with respect to the
workstation to allow the keyboard to be stored in a storage
position and be moved to an in use position; c) a linkage for
adjusting a relative position of the keyboard engaging member with
respect to the workstation engaging member and thereby adjusting a
keyboard position with respect to the workstation; and d) wherein
said workstation engaging member comprises: i) a housing supporting
a track defining a generally linear travel path, ii) a progressive
ball bearing slide movable along the track, said ball bearing slide
comprising ball bearings disposed within a plane generally parallel
to said workstation; iii) a keyboard support carriage supported by
the ball bearing slide for movement along the track.
16. The apparatus of claim 15 wherein the housing supports two
spaced apart linearly extending tracks wherein each of said tracks
includes first and second spaced apart wall surfaces that bound the
progressive ball bearing slide.
17. The apparatus of claim 16 wherein the progressive ball bearing
slide includes an array of ball bearings trapped at spaced
locations along the progressive slide for rolling engagement with
the wall surfaces of the track.
18. The apparatus of claim 15 wherein the linkage comprises first
and second linkage arms pivotally supported at spaced apart
locations so that the first and second linkage arms pivot
independently from each other during height and orientation
adjustment of the keyboard with respect to the workstation.
19. Apparatus for movably supporting a keyboard with respect to a
workstation comprising: a) a keyboard engaging member having a
generally planar keyboard support surface whose orientation is
controlled to control an orientation of the keyboard with respect
to a work surface of said workstation; said keyboard engaging
member comprising two parallel side pieces spaced apart by a center
section, said side pieces defining aligned slots on opposite sides
of the center section; b) a workstation engaging member that
supports the keyboard for back and forth movement with respect to
the workstation to allow the keyboard to be stored in a storage
position and be moved to an in use position; and c) a linkage for
adjusting a relative position of the keyboard engaging member with
respect to the workstation engaging member and thereby adjusting a
keyboard position with respect to the workstation comprising: i) an
arcuate slot at an end spaced from the end that is mounted to the
workstation engaging member; ii) a connector passing through said
arcuate slot and said aligned slots of said keyboard engaging
member, iii) a wedge carried by the connector; and iv) a knob
connected to the connector to adjust the pressure on the wedge to
adjust the orientation of the keyboard member by moving the
connector within the arcuate slot, and d) wherein said workstation
engaging member comprises: i) at least one horizontally oriented
track in which said linkage may ride; ii) a horizontally oriented
progressive ball bearing slide movable along the length of the
track comprising ball bearings disposed in a plane generally
parallel to the workstation; iii) a keyboard support carriage
supported by the ball bearing slide and movable along the slide.
Description
FIELD OF THE INVENTION
[0001] The present invention concerns a keyboard support for
orienting a keyboard such as a computer keyboard with respect to a
workstation surface.
BACKGROUND ART
[0002] The personal computer revolution has placed personal
computers and computer terminals on corporate and home desktops
throughout the world. Almost all such computers and terminals allow
data entry through an alphanumeric keyboard. Often such a keyboard
rests on a level desktop surface which is the same as the surface
that supports the computer.
[0003] Especially when the user must work at the computer for long
periods of time, it is important to be able to adjust the position
and/or orientation of the keyboard. Built in tabs that form an
integral part of the keyboard allow a limited amount of tilt
adjustment. To allow more flexibility, however, the keyboard needs
its own support.
[0004] Different types of keyboard supports are sold by Workrite
Ergonomics Accessories Inc., assignee of the present invention. One
such keyboard support is movably supported by a track that allows
the keyboard to be retracted out from under a user's desk and then
stored beneath the desk when the keyboard is not in use. This
keyboard support also allows the user to adjust both the angle and
the height of the keyboard in relation to its user. The tilt angles
of the keyboard can be adjusted through a continuously variable
angle of a total of 25 degrees from a negative tilt (front of
keyboard elevated with respect to its back) of 15 degrees to a
positive tilt (front of keyboard lower than its back) of 10
degrees. This commercially available keyboard is sold by Workrite
under the model designation numbers 170, 171, 173, and 175.
[0005] Waterloo Furniture Components presently sells a support
mechanism that includes a moveable linkage that couples a keyboard
support to a desk. The keyboard support rides in a track support on
progressive ball bearing slides that are oriented vertically, such
that the ball bearings are disposed within planes generally
perpendicular to the desk. A tab that extends from the track
support housing is pressed by the user to retract and store the
keyboard support. The height of the keyboard support is adjusted by
rotating the keyboard support up and moving the keyboard support to
the desired height and then releasing the keyboard support. The
height of the keyboard support is maintained by a braking system
made up of two wedge shaped blocks and two bolt holding the blocks
within an inclined slot. The Waterloo linkage also includes a
mechanism that allows a tilt angle to be varied over a range of
about 6 degrees by loosening and then re-tightening a self locking
nut. When the locking unit is loosened, a pin can be repositioned
within a limited extent slot in a member that forms part of the
linkage. This adjustment is made when the keyboard support is being
fabricated and is not adjustable by the keyboard user.
SUMMARY OF THE INVENTION
[0006] One exemplary embodiment of the present invention concerns a
keyboard support that allows a keyboard (typically a computer
keyboard) to be moved and reoriented with respect to a
workstation.
[0007] A keyboard supporting member has a generally planar keyboard
support surface whose orientation is adjustable. A second,
workstation engaging member allows the user to move the keyboard
back and forth with respect to the workstation. The movement of the
keyboard within the workstation engaging member may be accomplished
on nylon slides or other suitable bearings. In an exemplary
embodiment of the invention, progressive ball bearing slides
oriented horizontally such that the ball bearings are disposed in a
plane generally parallel to the workstation are located in the
workstation engaging member to allow the user to move the keyboard
to a storage position and then move the keyboard to an in use
position. This horizontal orientation of the ball bearing slides
provides a workstation engaging member having a lower profile than
prior art devices. A latch mechanism prevents movement of the
keyboard back to the storage position after the keyboard in
extended to the in use position unless a lever is pressed. A
linkage interconnects the two members for adjusting a relative
position of the keyboard supporting member with respect to the
workstation engaging member thereby allowing the keyboard position
and orientation to be controlled by the user.
[0008] The linkage includes a bracket having one end rotatably
connected to the workstation engaging member. The bracket extends
away from the workstation engaging member at an angle that controls
the height of the keyboard in relation to the work surface. The
bracket defines a pair of arcuate slots at one end spaced from the
end that is connected to the workstation engaging member. The
keyboard engaging member defines a pair of fingers each having an
arcuate slot located at either side of the planar support surface.
A connector passes through the arcuate slots of the bracket, the
arcuate slots of the keyboard engaging member, a preload spring,
and two wedge shaped pressure applying blocks. The pressure
applying blocks exert an inward force on the fingers of the
keyboard engaging member which in turn are frictionally engaged
with the bracket. The preload spring maintains engagement between
the blocks and the arcuate slots. As the force from the pressure
applying blocks increases so does the friction force between the
bracket and keyboard engaging member, tending to prevent relative
motion therebetween. The connector is used for increasing and
decreasing a frictional engagement between the pressure applying
blocks, the bracket and the keyboard engaging member. As the
frictional engagement is increased or decreased by the connector,
the wedge shaped pressure applying blocks are urged along an
incline in the fingers of the keyboard engaging member and the user
is able to adjust an orientation between the keyboard engaging
member and the workstation over a continuous range of values. As a
example of the exemplary embodiment, tilt angles over a range of 25
degrees can be chosen.
[0009] The keyboard engaging member may be manually rotated in a
direction which releases the frictional engagement between the
pressure applying blocks and the keyboard engaging member's
inclined finger segments allowing free movement of the bracket
relative to the workstation engaging member and the user may adjust
the height of the keyboard engaging member relative to the
workstation. When the bracket is released, the pressure applying
blocks move back their original position prior to the manual
rotation of the bracket thereby preserving the user's preferred
orientation.
[0010] These and other advantages and features of the present
invention will become better understood from a detailed description
of an exemplary embodiment of the invention which is described in
conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0011] FIG. 1 is a perspective view of a keyboard support
constructed in accordance with an exemplary embodiment of the
present invention;
[0012] FIG. 2 is an exploded perspective view of the keyboard
support depicted in FIG. 1;
[0013] FIG. 3 is an elevation view of the keyboard support of FIGS.
1 and 2;
[0014] FIG. 4 is second segmented elevation view of the keyboard
support wherein the keyboard contacting portion of the support has
been rotated to a different orientation;
[0015] FIG. 5 is a bottom plan view, partially in section of the
keyboard support depicted in FIGS. 1 and 2;
[0016] FIG. 6 is an elevation view of the keyboard support wherein
the user has lowered the height of the keyboard with respect to a
work surface but maintained an orientation with respect to the
horizontal the same as the depiction in FIG. 4;
[0017] FIGS. 7 and 8 are perspective views of two pressure applying
blocks used with an exemplary embodiment of the present
invention;
[0018] FIG. 9 is a perspective view of a linkage cover
assembly;
[0019] FIG. 10 is an enlarged side view of a workstation engaging
member having a linear progressive ball bearing slide in a
horizontal orientation shown in phantom line;
[0020] FIG. 11 is a front view of the workstation engaging member
shown in FIG. 10;
[0021] FIG. 12 is a top plan view of a track for the progressive
linear ball bearing slide;
[0022] FIG. 13 is a top plan view of a ball bearing retainer;
and
[0023] FIG. 14 is a view of the retainer as seen from the plane
14-14 in FIG. 13.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
[0024] FIG. 1 depicts a keyboard support 10 constructed in
accordance with one exemplary embodiment of the invention. The
support 10 is intended to position a keyboard 12 with respect to a
workstation such as a desk 14. A keyboard engaging member 20 has
two spaced apart, generally planar keyboard support surfaces 22a,
22b that define a keyboard orientation relative to the desk 14. A
workstation engaging member 30 in the form of an elongated metal
housing has a top planar surface 31 that attaches to an
undersurface of the desk 14 and supports the keyboard 12 for back
and forth movement with respect to the desk 14. The workstation
engaging member 30 attaches to a flat undersurface 14a of the desk
14 by means of a plurality of fasteners (not shown). This allows
the keyboard to be moved to a storage position beneath the flat
level undersurface 14a of the desk 14. A linkage 40 interconnects
the keyboard engaging member 20 and a carriage 32 (see FIG. 3) and
adjusts a relative height and orientation of the keyboard 12 with
respect to the desk 14. As described below the orientation is
continuously adjustable over a range of about 25 degrees and) for
example, two different orientations of the keyboard 12 are depicted
in FIGS. 3 and 4. In FIG. 3 the keyboard engaging member 20 orients
the keyboard generally horizontal with respect to the top surface
31 of the housing 30 that engages the desk 14 and in FIG. 4 the
keyboard has a negative tilt.
[0025] When an operator is seated at the desk 14, the keyboard 12
is moved out from under the desk to an in use position in front of
the desk. The back and forth movement of the keyboard is provided
by progressive ball bearing slides 39 having bearings that movably
support a carriage bracket 37 connected to the carriage 32 (FIGS.
10 and 11) for movement along a generally linear travel path within
tracks 28 riveted to "U" shaped channels 29 (also shown in FIG. 1).
The slides 39 may travel the length of the housing 30 and the
carriage bracket 37 travels with the slides 39 along the length of
the slides. The ball bearing slides 39 are oriented horizontally,
with the ball bearings 39a disposed in a plane P generally parallel
to a worksurface of the workstation 14 (shown in FIGS. 1 and 11).
This allows the housing to have a relatively low profile. The
carriage 32 has a forwardly extending lip 33 which interacts with a
latch 36 to prevent movement of the carriage 32 to the storage
position once the carriage has traveled to the fully extended
position as shown in FIG. 3. Once the carriage 32 has been latched
into place by the latch 36 the user must press down on a lever 35
to disengage the latch 36 from the lip 33 to slide the carriage 32
back to the storage position. The lever 35 protrudes through a face
cover 162 in the housing 30 which defines a low profile rectangular
surface having dimensions of approximately 9.25 by 0.75 inches. Two
downwardly extending supports 34 (only one of which is visible in
the drawings) are connected to the carriage 32 and move back and
forth along the generally linear travel path with the carriage. In
order to reduce the housing 30 dimensions, the progressive ball
bearing slides 39 such as Waterloo part numbers 612060R2175 and
612060L2175 are oriented horizontally to permit the housing 30 to
have a low profile.
[0026] With particular reference to FIG. 2, the linkage 40 includes
a back bracket 42 and a pair of elongated arms 44a, 44b all
supported by the downwardly extending supports 34. The bracket 42
has two downwardly extending sidewalls 46, 48 that are bridged by a
generally planar center sheet 50. The sidewalls include openings
that accommodate a bearing in the form of a rod 52 that is attached
to the downwardly extending supports 34, and tabs 66, 68 and
arcuate slots 64 spaced apart from the openings that accommodate
the rod 52. The two elongated arms also define openings that
accommodate a bearing in the form of a second rod 54 that is also
attached to the downwardly extending supports 34. A counterbalance
spring 38 is disposed around the rod 52 to assist the user in
raising the keyboard support 10.
[0027] The keyboard engaging member, also referred to as the front
bracket 20 is a metal stamping that is bent to form two generally
parallel side pieces 110, 112 that extend from a center section
114. The keyboard support surfaces 22a, 22b are provided by bending
a portion of the side pieces 110, 112 at right angles to form
outwardly extending tabs having holes 116 extending through the
tabs to accommodate connectors (not shown) for attaching the
keyboard to the front bracket 20.
[0028] The side piece 110 of the front bracket stamping 20 also
defines two fingers 120, 122 that define an engagement between the
front bracket and the linkage 40. Similarly, an oppositely
extending side piece 112 defines two fingers 124, 126 on an
opposite side of the linkage 40 that define that engagement. The
finger 120 is generally coplanar with the sidewall 110 and defines
an opening 130 which aligns with an opening 132 in the tab 68 of
the back bracket 42 when the front and back brackets are pivotally
connected together. In an analogous fashion the finger 124 is
generally coplanar with the sidewall 112 and defines an opening 140
which aligns with an opening 142 in the tab 66 of the back bracket
42 when the front and back brackets are pivotally connected
together. A rod 150 extends through the respective openings 130,
132, 140, 142 to allow relatively unrestricted relative rotation
between the front and back brackets 20, 42 about an axis coincident
with the rod 150. The rod 150 also extends through a linkage cover
assembly 160 which is disposed between fingers 120 and 124 to
protect the linkage from debris and present an attractive
appearance to the assembled keyboard support 10.
[0029] As seen by reference to FIGS. 3 and 6 the angle between the
bracket 42 and the two supports 34 determine the height of the
keyboard in relation to the desk. The angle between the bracket 42
and the two supports 34 is in turn determined by the position of
threaded rod 62 along the arcuate slots 64. As depicted in FIG. 3,
the bracket 42 extends away from the desk in a direction generally
parallel to the desk top or work surface 14a. This corresponds to a
maximum keyboard height adjustment for the support 10. Turning to
FIG. 6, one sees the bracket 42 forms an angle with respect to the
horizontal of about 60 degrees. This is accomplished by rotating
the bracket downward away from the orientation shown in FIG. 3.
[0030] The bottom plan view of FIG. 5 depicts details of the
frictional engagement that secures the front bracket 20 in a
particular orientation and height. The two fingers 122, 126 bend
away from their respective side walls 110, 112 at generally right
angles and then back along incline defining segments 122a, 126a
toward the plane of the sidewalls 110, 112. Where the incline
defining segments 122a, 126a of the two fingers reach the plane of
the sidewalls 110, 112 they are again bent to form segments 122b,
126b that are generally coplanar with the side walls 110, 112. When
the support 10 is assembled inwardly facing surfaces of these
segments 122b, 126b frictionally engage tabs 68, 66 of back bracket
42.
[0031] The incline defining segments 122a, 126a of the fingers 122,
126 define two arcuate slots 145, 146 which accommodate passage of
the threaded rod 62 to which a knob 60 attaches and which allow the
orientation of the keyboard to be adjusted through a range of
twenty-five degrees or the extent of the arc of the two-slots 140,
142. Two blocks or wedges 150, 152 (FIGS. 7 and 8) having openings
154, 156 passing through their bodies, and slides 171, 172 are
pressed into the arcuate slots 145, 146 that extend through the
angled segments 122a, 126a of the fingers 122, 126. A spring
engaging block 152 (located on the right in FIG. 2) has an integral
bearing 156 around which a preload spring 153 may rotate. The
slides 171, 172 engage the arcuate slots 145, 146 and ride within
them. The preload spring 153 exerts an inward force on the blocks
150, 152 to retain the slides 171, 172 within their respective
channels or slots 145, 146 as the keyboard orientation is adjusted.
As seen in FIG. 5, the finger segments 122b, 126b press against
outer surfaces of the two tabs 66, 68 of the back bracket 42 along
the region of the arcuate slots 64. The blocks 150, 152 exert
pressure against the inclined segments 122a, 126a of the fingers
122, 126 which in turn exerts pressure of engagement between the
segments finger segments 122b, 126b against the two tabs 66, 68 of
the bracket 42.
[0032] A downward pressure on the keyboard engaging member 20
(tending to rotate the number 20 in a clockwise direction as seen
in FIG. 3) urges the blocks 151, 152 apart and tends to move them
along the inclined arcuate slots 145, 146 toward the keyboard
support center section 114. This also increases the pressure, and
hence frictional resistance, between the finger segments 122b, 126b
and the tabs 66, 68 due to the interaction between the wedge shaped
blocks 151, 152 and the incline defining segments 122a, 126a. The
increased friction locks the relative position of the finger
segments 122a, 126a and the tabs 66, 68 which prevents movement of
the rod 62 along the arcuate slots 64 thereby providing a self
locking feature which prevents unintended downward motion of the
keyboard support.
[0033] To adjust the height of the keyboard support, the user
rotates the keyboard engaging member 20 in an upward direction
(counterclockwise in FIG. 3). This movement urges the blocks 151,
152 to move along the arcuate slots 145, 146 in a direction away
from the center section 114, Due to the interaction between the
blocks 151, 152 and the inclined finger segments 145, 146, this
motion decreases the pressure, and hence the frictional resistance,
between the inclined finger segments 122a, 126a and tabs 66, 68
which allows the rod 62 to travel within the arcuate slot 64 and
thereby allows the height of the keyboard support to be adjusted.
The preload spring 153 maintains the slides 171, 172 in the slots
while pressure on them is released. When the user releases the
keyboard engaging member 20, the blocks 151, 152 return to their
original position providing friction to prevent further movement of
the rod 62 within arcuate slots 64, locking the height of the
keyboard support.
[0034] The adjusting knob 60 allows the user to control the
orientation of the keyboard. The knob 60 threadingly engages the
elongated rod 62 and traps the spring 153 between the knob 60 and
the block 152. By rotating the knob 60 the user can apply or
release pressure on the pressure applying blocks 151, 152 as the
knob 60 is rotated. Applying pressure by rotating the knob 60 in a
direction which tends to shorten the distance-between the two
pressure applying blocks 151, 152 urges the blocks to move down
along the inclined segments 122a, 126a resulting in a positive
angular change in keyboard orientation. Rotating the knob in the
opposite direction decreases pressure on the pressure applying
blocks causing them to move up the inclined segments 122a, 126a
producing a negative angular change in keyboard orientation.
[0035] A force in a downward direction on the keyboard engaging
member 20 (clockwise in FIG. 2) applies a torque about the rod 150
along a lever arm defined by the pivot of the rod 150 and the
slides 171, 172 of the blocks 151, 152. This torque tends to
produce a clockwise motion of the keyboard engaging member 20.
However, as the keyboard engaging member is urged clockwise, the
blocks 151, 152 are urged up the inclined fingers 122a, 126a and
since the distance between the blocks 151, 152 has not changed, the
pressure between the blocks 151, 152 and the fingers 122, 126 is
increased due to the interaction between the wedge shaped blocks
151, 152 and the incline of the segments 122a, 126a. As this
pressure increases, the friction force between the blocks 151, 152
prevents movement of the keyboard engaging member 20 about the rod
150. In addition, the increased pressure between the blocks 151,
152 and the fingers 122, 126 also tends to squeeze against the tabs
66, 68 increasing the friction force between the fingers 122, 126
and the tabs 66, 68 to prevent motion of the linkage 140 about the
rod 150. Therefore, due to the self locking feature of the keyboard
support, a downward force on the keyboard engaging member 20 will
not cause motion of the keyboard support.
[0036] Turning now to FIGS. 12-14, details of the linear one of the
two linear slides are depicted. Each slide 28 supports a bracket
200 that is attached to the carriage bracket 37 by means of
suitable connectors 202. A ball bearing retainer 210 has opposite
bearing retainer cages that extend along either side of the
retainer for supporting the balls thereby forming spaced apart ball
bearing arrays 212, 214. The bracket 200 is attached to the slide
39 which is supported by the ball bearing arrays 212, 214 for
movement back and forth as the user slides the keyboard out from
under the workstation. Further details of the slide may be obtained
by reference to the Waterloo slide whose part numbers are reference
above. As seen in the depiction of FIG. 11 orientation of the
slides 39 within the housing 30 results in a low profile housing
having a height of no more than 75 inches. An improvement over the
prior art structures which tended to come into contact with the
keyboard as the keyboard was pushed into its storage position
beneath the work surface.
[0037] It is appreciated that while a preferred embodiment of the
invention has been described, it is the intent that the invention
include all modifications and alterations from the disclosed design
falling within the spirit or scope of the appended claims.
* * * * *