[0001] The present invention relates to a modular height adjustment system and in particular
to a modular height adjustment system for use in connection with a desk or with a
desk system comprising two or more interconnected desks.
[0002] Desks are used by a variety of people for a number of jobs and accordingly various
heights of desks are required. Often, desks are bought to suit a particular person
and the job that they do, which can be inconvenient and costly when people change
jobs.
[0003] A particular object of the present invention is to provide a height adjustment system
for use in a desk or desk system to allow the height to be adjusted to suit a variety
of people and jobs. The modular height adjustment system can be used in conjunction
with desks, tables and work benches for use in industrial and educational applications.
[0004] In the context of the present invention, "desk system" is to be construed as two
or more interconnecting desks.
[0005] In a first aspect, the present invention provides a modular height adjustment system
comprising one or more supports adapted to be longitudinally extended or contracted.
[0006] In a second aspect, the present invention provides one or more supports for use in
connection with a desk or with a desk system (as herein above defined) in which each
said support is adapted to be longitudinally extended or contracted.
[0007] The means to extend or contract each support (hereinafter referred to as the lifting
apparatus) preferably comprises an outer tube of a first diameter having an internal
screw thread and an inner tube of a second diameter having a complementary external
screw thread. The first diameter is larger than the second diameter and the internal
and external screw threads engage to allow the inner tube to be received within the
outer tube.
[0008] Preferably the outer tube forms the bottom portion of the lifting apparatus and the
inner tube forms the top portion of the lifting apparatus. The upper end of the inner
tube is preferably shaped to receive a drive boss and may be provided with a shoulder
to receive one or more washers below the drive boss. One of the washers preferably
comprises a roller bearing.
[0009] The outer and/or inner tubes may be provided with stop means to prevent the inner
tube from being removed from the outer tube.
[0010] In a third aspect, the present invention provides a desk assembly comprising a work-surface
and one or more supports in which each said support is adapted to be longitudinally
extended or contracted, whereby the work-surface is respectively raised or lowered
relative to the supports.
[0011] Preferably the supports are as hereinabove defined with reference to the first and
second aspects of the invention.
[0012] Preferably the desk assembly is provided with two supports, which may be spaced apart
to form leg-ends for the desk. Each leg-end is preferably provided with a supporting
foot extending substantially at right angles to the leg-end. The supporting foot may
be provided with one or more protrusions to allow easier movement of the desk assembly.
Preferably the support foot is made by extrusion, most preferably from aluminium.
[0013] Preferably the lower end of the outer tube of the lifting apparatus is secured to
a solid base, for example the support foot, substantially at right angles thereto.
[0014] Preferably the lifting apparatus is contained within an outer casing which may suitably
comprise a lower portion of a first diameter telescopically received within an upper
portion of a second diameter.
[0015] Preferably the casing is made by extrusion, most preferably from aluminium.
[0016] The lower portion of the casing is preferably secured to the support foot.
[0017] The top surface of the upper portion is preferably provided with an aperture through
which the upper end of the inner tube of the lifting apparatus can pass before the
washers and drive boss are secured thereto.
[0018] On rotating the drive boss the inner tube of the lifting apparatus can be screwed
into or out of the outer tube to decrease or increase the height of the lifting apparatus.
The outer casing is engaged by, and therefore contracts or extends, with the lifting
apparatus by means of the telescopic engagement of the upper and lower portions.
[0019] Preferably, two members are provided to support the work-surface, one member being
secured to the upper portion of each outer casing. Each support member preferably
comprises a bracket, which may have secured thereto a rail shaped to receive the work-surface
and hold it in place. Each bracket may be adjustable relative to the casing to allow
the angle of the work-surface to be altered.
[0020] The work-surface is preferably a desk or table-top. Alternatively, it may be a drawing
board or a computer station.
[0021] As the outer casing contracts or extends with the lifting apparatus the work-surface
is respectively lowered or raised.
[0022] The lifting apparatus is provided with drive means. Preferably, a single drive means
is operatively associated with all of the sets of lifting apparatus of the desk assembly.
[0023] Where there are two sets of lifting apparatus the drive means comprises a longitudinal
drive body, preferably made by extrusion, e.g., from aluminium. A single gear housing
is preferably secured to one end and a single gear housing or alternatively a twin
gear housing is secured to the opposite end.
[0024] Suitably, a first and a second sprocket are located one at each end of the drive
body, preferably in the gear housings, each receiving the drive boss of one of the
two sets of lifting apparatus.
[0025] Conveniently, each drive boss is received in a gear housing by way of an aperture
provided in the base of the housing.
[0026] A further sprocket may be provided to act as a main drive sprocket and may be located
in the twin gear housing. Such a main drive sprocket will have operatively associated
therewith means to rotate the drive sprocket. Alternatively where there is not a main
drive sprocket the first or second sprocket may be associated with means to rotate
the said sprockets. The means may be a handle (e.g. a crank handle) or a motor received
by the drive sprocket through a second aperture in the twin gear housing or by the
first or second sprocket through a second aperture in the single gear housing.
[0027] A drive belt engages both (or all three) sprockets such that the drive sprocket or
one of the first or second sprockets rotates the drive belt and therefore all remaining
sprockets, which in turn rotate the drive bosses and consequently the inner threaded
tube of the lifting apparatus, to adjust the height of the desk.
[0028] The desk system may be provided with a modesty board extending between the leg-ends.
The modesty board is preferably made by extrusion, most preferably from aluminium.
[0029] The means provided to drive the lifting means of two or more desk assemblies may
be joined together and operated by a single drive sprocket, or one of the first or
second sprockets, and an associated handle or motor.
[0030] According to a fourth aspect, the present invention provides a kit comprising at
least two sets of lifting apparatus, means to drive the lifting apparatus and optionally
means to support a work-surface, the lifting apparatus, the means to drive the lifting
apparatus and the means to support the work-surface all being as described in respect
of the first aspect of the present invention.
[0031] The kit may further comprise outer casings to surround each lifting apparatus and
comprising upper and lower portions telescopically engaging each other. A support
foot may be provided for each set of lifting apparatus.
[0032] The work-surface, which may consist of a desk or a table-top, a drawing board or
a computer station, may be provided as part of the kit.
[0033] The kit may include a modesty board.
[0034] The parts of the kit are preferably labelled and assembly instructions are preferably
provided.
[0035] An embodiment of the present invention will now be described, by way of example only,
with reference to the accompanying drawings, in which:
Figure 1 illustrates a height adjustment system according to the present invention;
Figure 2 illustrates a desk system according to one embodiment of the present invention;
Figure 3 illustrates the drive means of the desk of Figure 2; and
Figure 4 shows the way in which four drive means of interconnecting desks can be operatively
connected and driven by a common motor.
[0036] Figure 1 shows the lifting apparatus which comprises an outer tube 8. The outer tube
8 has an internal screw thread and receives an inner tube 10 having a complementary
external screw thread.
[0037] The end 10a of inner tube 10 is provided with a shoulder 11 and cut away portion
12. A first washer 13, a roller bearing 14 and a second washer 15 rest on the shoulder
11. A drive boss 16 fits over the end 10a and when turned causes the inner tube 10
to be screwed into or unscrewed from the outer tube 9. A stop (not shown) is provided
to prevent the inner tube 10 from being completely removed from the outer tube 9.
[0038] Figure 2 shows the desk assembly 1 of an embodiment of the present invention, having
support feet 2 extending from, and substantially at right angles to, the lower portion
3a of outer casing 3, which lower portion 3a is telescopically received within upper
portion 3b of the casing 3. The casing 3 is secured to feet 2 by means of screws such
as M8 x 25 Hex Socket Screws which pass through the feet 2 and into receiving brackets
inside the lower portion 3a of casing 3. The outer casing 3 and feet 2 are extruded
aluminium profiles whose open ends have been capped by an injection moulding of a
plastics material.
[0039] A modesty board 4, also of extruded aluminium, extends between and is secured to
the upper portions 3b of the outer casings 3. The modesty board 4 is secured to the
outer casings 3 by being secured by screws such as M6 x 30 CSK Hex Socket Screws to
two moulded ends which are then received by corresponding recesses on the upper portion
3b of casing 3.
[0040] Support brackets 5 extend one from each upper portion 3b of casing 3 and slidingly
receive rails 6 which are shaped to support a flat desk top (not shown). The support
brackets are secured to the upper portion 3b of the casing 3 by screws such as M6
x 15 Hex Socket Screws.
[0041] Within the outer casing 3 is housed the lifting apparatus 7 shown in Figure 1, the
outer tube 8 being secured to the foot 2 by means of a bolt (not shown) and washer
9.
[0042] The washers 13, 14 and 15 are placed over the end 10a of the inner tube 10, followed
by the drive boss 16, once the end 10a has been passed through a hole (not shown)
in the end 3c of the upper portion 3b of casing 3.
[0043] A drive body 17 (see Figure 3), having a single gear housing 18 and 19 secured to
each end, extends between the ends 3c of the upper portion 3b of the outer casings
3.
[0044] A first sprocket 20 is situated in the single gear housing 18 and a second sprocket
21 is situated in the single gear housing 19. A drive belt 23 engages both sprockets
20 and 21.
[0045] The gear housings have apertures aligned with sprockets 20 and 21 to allow the drive
bosses 16 of the lifting apparatus 7 to engage the sprockets 20 and 21 and a further
aperture aligned with sprocket 21 to allow a drive handle (not shown) or a motor 24
to engage sprocket 21.
[0046] In use the motor 24 (or handle, not shown) drives the drive belt 23 by means of the
drive sprocket 21, which in turn drives the sprocket 20 and rotates the inner tubes
10 of the lifting apparatus 7 by means of the drive bosses 16, which are consequently
screwed into or out of the outer tube 9 depending upon the direction of the rotation.
[0047] As the lifting apparatus 7 extends or contracts the casing 3 extends or contracts
by means of telescopic engagement of the upper and lower portions. The support rails
6 and therefore the desk top are raised or lowered accordingly. When the motor 24
is stopped the position of the desk top is maintained.
[0048] Figure 4 shows the drive body 17 of figure 3 having a single gear housing 18 and
19 at each end to contain the sprockets 20 and 21 respectively.
[0049] The gear housings 18 and 19 have apertures in both faces. The apertures are to be
aligned with the centres of the sprockets 20 and 21, the apertures in the lower faces
receiving the drive bosses 16 of the lifting apparatus 7 and the apertures in the
upper face receiving double sprocket adapters 25 to allow the sprockets (not shown)
of further drive bodies, 26 and 27, to be operatively connected with the sprockets
of drive body 17 and a further drive body 28 is adapted to be operatively connected
to drive body 27. Each of the further drive bodies is made up of the same components
as the first drive body 17 and each receives lifting apparatus as described in the
relation to the earlier Figures. However, the lifting apparatus is shared between
connected drive bodies, for example a common lifting apparatus will be used where
drive bodies 26 and 17 connect, where drive bodies 27 and 17 connect and where drive
bodies 27 and 28 connect.
[0050] The motor 24 or handle 29 can engage any of the sprockets contained within the drive
body gear housings, for example sprocket 21 in gear housing 19, by means of the gear
housing 30 of drive body 26 and the sprocket contained therein, together with the
connector 25. Alternatively it can engage the sprocket in the gear housing 31 of drive
body 26, where the handle 29 is located, as shown in Figure 4.
[0051] The drive bodies 17, 26, 27 and 28 form part of a desk system comprising the components
of the desk assembly of Figure 2, although only the drive bodies and connection means
are shown in Figure 4.
1. An elongate support for use in connection with a desk (1) or with a desk system comprising
two or more interconnected desks, characterised in that said support (3) is provided with means (7) adapted to cause longitudinal extension
or contraction of said support (3).
2. A support as claimed in Claim 1, characterised in that the means (7) comprises an outer tube (8) of a first diameter and having an internal
screw thread and an inner tube (10) of a second diameter and having a complementary
external screw thread, and the internal and external screw threads engage to allow
the inner tube (10) to be received within the outer tube (8).
3. A support as claimed in Claim 2, characterised in that one end (10a) of the inner tube (10) is shaped to receive a drive boss (16).
4. A support as claimed in Claim 3, characterised in that the end (10a) of the inner tube (10) is provided with a shoulder (11) to receive
one or more washers (13, 14, 15) below the drive boss (16).
5. A support as claimed in Claim 4, characterised in that one of the washers (13, 14, 15) comprises a roller bearing (14).
6. A desk assembly, characterised by a work-surface operatively associated with one or more supports according to any
one of Claims 1 to 5, whereby the work-surface is adapted to be respectively raised
or lowered relative to the supports.
7. A desk assembly as claimed in Claim 6, characterised in that each means (7) is contained within an outer casing (3) comprising a lower portion
(3a) of a first diameter telescopically received within an upper portion (3b) of a
second diameter.
8. A desk assembly as claimed in Claim 7, characterised in that the lower portion (3a) of the outer casing (3) is secured to a base member (2) which
extends substantially at right angles to the portion (3a).
9. A desk assembly as claimed in any one of Claims 6 to 8, characterised in that the means (7) is provided with drive means, for example, a single drive means operatively
associated with all of the means (7) of the desk assembly.
10. A desk assembly as claimed in Claim 9, characterised in that it includes two sets of means (7) and the drive means is contained within an elongate
drive housing (17) having a first gear housing (18) secured to one end and a second
gear housing (19) secured to the opposite end, each gear housing containing a sprocket
(20, 21) and each sprocket being operatively associated with the drive boss (16) of
a means (7), each drive boss (16) being received in a gear housing (18, 19) by way
of an aperture provided in the base of the housing (18, 19).
11. A desk assembly as claimed in Claim 10, characterised in that one of the sprockets (20, 21) is operatively associated with means to rotate the
said sprocket, for example, a handle or a motor (24) received by the sprocket (20,
21) through an aperture in the gear housing (18, 19).
12. A desk assembly as claimed in Claim 10 or 11, characterised in that a drive belt or chain (23) engages the sprockets (20, 21), thereby rotating each
drive boss (16) and consequently each inner threaded tube (10) to adjust the height
of the desk.
13. A desk system comprising two or more desk assemblies as claimed in any one of Claims
6 to 12, characterised in that the drive means of said two or more desk assemblies are operated by a common drive
sprocket.
14. A kit characterised by (i) at least two sets of extension and contraction means as claimed in any one of
Claims 1 to 5 and (ii) drive means as claimed in any one of Claims 9 to 12.