Supervisory desk

A supervisory desk comprises a top section with a desk surface, or the like, a stand section with at least one leg of adjustable length which supports the top section so that the height of the top section above the stand section can be adjusted. The leg(s) is/are inclined (e.g. at 45.degree.) to the vertical plane, whereby ergonomic conditions are obtained for an operator using the desk having regard to the height of the desk surface, the leg space below the top section and the view over the rear edge of the desk surface.

TECHNICAL FIELD 
The present invention relates to a supervisory desk comprising a top 
section with a desk surface or the like and a stand section supporting the 
top section via at least one leg of adjustable length. Desks of this kind 
are used, for example, for the control of electric power systems and 
industrial processing plants and commonly incorporate a cabinet which 
houses electrical equipment, for example for communication between a 
keyboard, disposed on or in the desk surface, and a computer. 
Such supervisory desks are often manned in shifts 24 hours a day. It is 
therefore desirable for the operating plane of the desk surface to be 
raisable and lowerable so that it can be easily adjusted to the physical 
sizes of the different operators who sit at the desk. 
Desks of the type to which the invention relates are often used in 
supervisors cabins overlooking workshops and the like. It is then a 
requirement that the operator has a good view over the rear edge of the 
desk, enabling the manufacturing processes in the workshop to be directly 
supervised from the cabin. 
DISCUSSION OF PRIOR ART 
It is known to contruct supervisory desks with vertical legs of variable 
length, so that the vertical position of the desk surface can be adjusted 
for each different operator. However, with such a design where the desk 
surface can only be displaced in the vertical direction, it is difficult 
to achieve, at one and the same desk, both sufficient leg space for tall 
operators and a good view over the rear edge of the desk for small 
operators. For reasons of space, among other things, the cabinet of the 
desk is placed on the floor below the rear edge of the desk top section 
and is fixedly mounted to the desk stand section. If the horizontal 
dimension between the cabinet (or terminal section) and the front edge of 
the desk surface is adjusted to the length of the legs of a tall person, 
short persons will have a bad view in an oblique downward direction over 
the rear edge of the desk. 
It is one object of the present invention to provide a supervisory desk of 
the above-mentioned kind, which is ergonomically adapted to the operator 
with respect to the height of the desk surface, the leg space, and the 
view over the rear edge of the desk. 
STATEMENT OF INVENTION 
According to the invention there is provided a supervisory desk comprising 
a top section having a front edge, a stand section with at least one leg 
of adjustable length which supports the top section so that the top 
section may be adjusted in height relative to the stand section, which is 
characterised in that said at least one adjustable leg is inclined 
forwardly with respect to a vertical plane in such a way that the front 
edge of the top section moves forwardly with respect to the stand section 
when the length of said at least one adjustable leg is increased.

DESCRIPTION OF PREFERRED EMBODIMENTS 
The supervisory desk shown in FIGS. 1 and 2 comprises a top section 1, 
having a support frame 2 and a desk top 3, a. stand section 4, comprising 
two leg units 4a, 4b arranged one at each opposite end of the desk, and a 
cabinet means, or terminal section, 5 disposed between the leg units 4a 
and 4b. Each leg unit has a foot 6 and an adjustable leg 7, the length of 
which may be changed so that the top section 1 can be set at different 
heights above the feet 6. FIG. 1 shows the top section 1 both in a lower 
position (unbroken lines) and in an upper position dash-dotted lines and 
reference numerals with a prime). The terminal section can be a cabinet 
housing electrical equipment for use by an operator sitting at the desk. 
Each adjustable leg 7 is fixed to the respective leg unit 4a, 4b and is 
inclined at an angle .alpha. with respect to a vertical plane. The angle 
.alpha. is desirably at least 15.degree. and at most 75.degree.. In all 
the embodiments shown in the drawings, the angle .alpha. is 45.degree., 
which gives optimum ergonomic operating conditions. However, angles for 
.alpha. in the range 35.degree. to 50.degree. can also be used and this is 
the preferred range for .alpha.. With a desk designed according to the 
invention, two changes of the ergonomic dimensions are obtained with a 
single adjustment movement, namely, a changed desk top height and a 
changed available leg space in front of the terminal section 5. At the 
same time the angle of view and the accessibility of the units located on 
the desk will be changed flexibly with the operator demands. 
The terminal section 5 of the first embodiment of supervisory desk shown in 
FIGS. 1 and 2 comprises a basic unit 51, the faces 52, 53 and 54 of which 
consist of easily removable panels of which there may be more than one per 
face. Such a design makes the terminal section easily serviced. The panels 
52 and 54 of the front and rear faces, respectively, may, if necessary, be 
made relatively deep to provide room for apparatus requiring a large 
dimension in that direction. One example of such an arrangement is shown 
in FIG. 1, where the front panel 52 projects forwardly of the stand 
section 4. The panels 53 on the upper side of the terminal section may 
form an extension of the terminal section, which could, for example, 
include a separate indicating section of the desk. 
The adjustable legs 7 of the desk, one embodiment of which is shown in more 
detail in FIGS. 3-7, consists of two tubular leg parts, an outer leg part 
8 and an inner leg part 9, both of which have a substantially rectangular 
cross-section. The inner leg part is telescopically received in the outer 
leg part. FIG. 3 shows the lower end of the inner leg part, both in the 
upper limiting position (dash-dotted lines and reference numerals with a 
prime) and in the lower limiting position (unbroken lines). Three support 
rollers 10, 11 and 12 are employed to guide the inner leg part within the 
outer leg part, the rollers 10 and 11 being journalled in the outer leg 
part and the roller 12 in the inner leg part. The roller 11 is adjustable 
for setting relative transverse play between the leg parts. 
The construction of the leg parts and the manner of their interengagement 
can be clearly seen from FIGS. 3 to 7 and will not be further described 
here. 
A drive unit for adjusting the height of the desk top comprises a geared 
electrical motor 13 which drives a shaft 14 around which is wrapped a 
flexible belt 15. The belt 15 is fixed to the inner leg part 9 by a bolt 
21 and its length is adapted to that required when the leg 7 is in its 
lower limiting position. The direction of movement of the belt is reversed 
around a deflector roll 16 (journalled in a bracket 22 fixed to the outer 
leg part 8) and is deflected around deflector rolls 17 and 18 between the 
roll 16 and the drive shaft 14. The deflector roll 18 is adjustable so 
that any differences in belt length and attachment of the driving belts 15 
at both ends of the desk may be compensated for. The extension of the leg 
7 is limited by engagement between a stop bar 19 (secured to the inner leg 
part 9 by the bolt 21) and an end 20 of the bracket 22. Electrical 
switches (not shown) can be used to turn off the motor powering the drive 
unit when the members 19/20 engage one another or as a substitute for the 
member 19 or 20. 
The belt 15 may consist of a synthetic fiber belt or a flexible steel belt, 
and its relative elongation (linear strain) under the working load should 
be small. In place of a belt, a rope or a wire could be used. The 
deflector rolls 17 and 18 may be dispensed with. 
With the aid of the drive unit described, the desk top may be raised to any 
arbitrary position between the lower and upper limiting positions. 
Lowering of the desk top occurs by reversing the direction of rotation of 
the shaft 14 and utilizing the weight of the top section 1. The drive unit 
described may be used in conjunction with gas springs mounted one in the 
cavity of each inner leg part. Such gas springs may, for example, be used 
to provide additional lifting power for augmenting the mechanical drive 
unit. Further, the lowering of the desk top may be facilitated by at least 
one gas spring which acts in the opposite direction to the belt 15 and 
serves to overcome starting friction of the inner leg part 9 in the outer 
peg part 8. 
Instead of the design shown in FIGS. 3-7, where a driving belt is used for 
lifting the desk top, the supervisory desk may, as an alternative, be 
raised by means of at least one gas spring to its upper limiting position 
and a driving belt or the like can then be used for pulling the desk top 
surface down to the desired level. 
FIGS. 8 and 9 show another embodiment of adjustable leg 7 for a supervisory 
desk. This embodiment also employs two tubular telescoping leg parts, an 
outer leg part 8 and an inner leg part 9, both again having a 
substantially rectangular cross-section. 
The upper end of the inner leg part 9 is provided with an attachment 24 for 
screwing to the support frame 2, whereas the lower end of the outer leg 
part 8 is provided with an attachment means 25 for screwing to the stand 
section 4 and the foot 6. For guiding the inner leg part, two slide 
bearings 26, 27, for example of tetrafluoroethylene are provided, one 
bearing 26 being fixed to the inner leg part 9 and the other bearing 27 
being fixed to the outer leg part 8. 
The drive unit for the adjustable leg in the embodiment of FIGS. 8 and 9 is 
a purely mechanical system with a drive nut 28 and a rotatable drive screw 
29. The drive nut 28 is fixed to the inner leg part 9 and the drive screw 
29 is driven via a gear unit 30, which in turn is fixed to the outer leg 
part 8. The gear unit 30 may, for example, include a worm gear which is 
driven by an electric motor (not shown) or a bevel gear connected to a 
handle for manual operation. The necessary drive force can be transmitted 
to the gear unit via an input shaft 31, and by using a common input shaft 
for all the legs of the desk, a synchronous extension or retraction of all 
the legs is ensured. 
Instead of the mechanical drive system shown in FIG. 8, a hydraulic system 
may be used, whereby the gear unit 30 is omitted and the drive screw 29 
and nut 28 in each leg 7 are replaced by a double-acting hydraulic 
piston-in-cylinder unit. The hydraulic cylinders in all the legs of the 
desk are then fed with pressurized fluid via a hose and a valve from a 
common electrically-operated hydraulic pump. 
It is also possible to use a simple manual drive system for the adjustable 
legs, each hydraulic piston-in-cylinder unit being replaced by a gas 
spring balancing the weight of the top section 1 and the desired extension 
of the legs 7 being mechanically locked by some manual catch means. 
FIG. 10 shows an embodiment of a supervisory desk according to the 
invention where the terminal section 5 consists of two smaller units 5a, 
5b, which are located adjacent to the right-hand and left-hand leg units 
4a, 4b, respectively, and connected to the inner side of the respective 
leg unit. This embodiment provides greater leg room for an operator 
sitting at the desk. 
FIG. 11 shows an embodiment, the upper part of which includes a display 
panel 33, an operating panel 34 and a writing panel 35. 
FIG. 12 shows an embodiment with a separate display section 36 which is 
mounted above the terminal section 5 on a vertical leg 37 of adjustable 
length, so that the height of the display panel on the section 36 can be 
adapted to selected height of the operating panel 34. 
FIG. 13 shows another embodiment again with a separate display section 36, 
which is supported by two extension legs 38 mounted on the stand sections 
4. This embodiment allows an operator a free view of articles beyond the 
desk through the gap between the display section 36 and the top section 1 
of the desk. An indicating panel 36a of the display section 36 is 
illuminated by a light source 39. Instead of spaced-apart extension legs 
38, a full cubicle section may be provided below the display section 36 
with additional display panels 36b and 36c. 
FIG. 14 shows an embodiment with a visual display unit 40 which is 
pivotally mounted on the rear edge of the top section 1 and on a 
supporting leg 41 of adjustable length which is pivotally mounted at its 
lower end on the stand section 4. With such a design, a suitable 
inclination of the visual display unit can easily be obtained for each 
height position of the top section 1, so as to optimize viewability (e.g. 
to avoid reflections from light sources). 
Between the terminal section 5 and the top section 1 of each embodiment of 
the desk, cable channels 32 (FIGS. 2 and 10) can be provided. FIG. 15 
shows how cables 42 are arranged in these channels and are fixed to a 
plate 43, which is connected to the top section 1 and moves slavishly 
therewith. This plate 43 may have a width which is equal to the width of 
the terminal section 5 or a part thereof. In the terminal section there is 
arranged a cable slack 44 which is anchored, for example, to a bar 45. In 
this way, full movement of the adjustable legs, from one limiting position 
to the other causes only a relatively small movement of the cables 42. The 
plate 43, with the cables, is surrounded by a protective housing 46, which 
can be easily dismantled during servicing. Alternatively, instead of the 
protective housing 46, an easily removable rubber bellows can be used to 
house the cables 42 which is connected to a connection piece on the 
underside of the top section 1 and a connection piece on the terminal 
section 5. 
The invention is not limited to the embodiments of desk shown in the 
drawings and several modifications are clearly feasible. For example, the 
terminal section 5 need not be employed to house electrical components but 
may be arranged solely as a protective screen for the operator.