Support for a forearm

Support for a person's forearm, adapted for use when working in a seated position, especially at a table, the underside of a longitudinal support cushion (8) being adapted for use as a seat for the user's forearm, the support cushion being secured to one part of a bearing, the support cushion being displaceable in the longitudinal direction of the cushion in relation to a second part of the bearing, which is adjustable in the height from and being connected to a socket arm (3), the support cushion furthermore being rotatable about a first substantially vertical axis (11), the socket arm being journalled to a clamp (9) for securement of the support to a working table, the socket arm being rotatable about a second substantially vertical axis (12) at a distance from the first axis (11), the clamp thereby being adapted for securement to the working place, such as the edge of a table, the longitudinal displacement allowing for movement of the user's hand from and towards the edge of the table, the distance between the two axes allowing for transversal displacement of the arm and the rotation of the cushion about the first axis allowing for the arm to be turned angularly about the first axis.

BACKGROUND OF THE INVENTION 
The present invention is related to a support for a person's forearm 
according to the preamble of the claims. 
Increasingly occupational deceases are found in connection with persons 
performing their daily work in a seated position thereby maintaining arms 
and hands at a level above the work to be performed. This in fact means 
static or almost static work in a considerable period of time of a working 
day. The work to be performed is limited to a relatively small working 
area, such as a typewriter, calculator or computer keyboard or assembly 
works of diferent kinds, such as in a production line, drawing works etc. 
Even when moving the hands within a limited area, the forces necessary for 
holding the hands and the forearms in a position above the working place, 
is so large that substantial counter forces have to be excited in the 
shoulders, the back, the back of the neck, the upper arm as well as the 
forearm and the wrists. This will be the case even when using a chair 
adequately adjusted to the person involved and the working place. The 
muscles of the body counteract naturally to the muscles supporting the 
weight of the hands and arms. As well known such counteracting give a 
number of problems to the body. 
Periods with pain in shoulders, back and back of the neck especially as 
well as in the elbow points frequently occurs in the above mentioned 
categories of work as well as others. The days of absence from work due to 
such problems is enormous and partly undiscovered. 
Several attempts have been made to solve these problems or decrease the 
pain and absence. Known is for example a support for the forearm which to 
a certain degree decreases the load as part of the forearm weight may be 
taken up by the device. A limitation, however, has been found in the use 
of such a support as the movement of the hand is limited and not given 
sufficient freedom within the necessary area. This solution therefore has 
not brought forward the final solution to these problems. 
In most cases as mentioned above, it is necessary for the hands to be moved 
freely, independently of each other within a limited area, however, 
substantially in the same horizontal or possibly inclined plane. With 
known solutions the arm must be lifted from the support if the fingers 
should cover the entire working area as mentioned above. This limitation 
substantially limits the use of the support and above all limits the 
contribution of the support to a relaxed working position for the entire 
body. 
SUMMARY OF THE INVENTION 
With the support for the forearm according to the present invention, a 
support is provided for an arm, or when using two distanced supports, even 
for both arms, thereby allowing movements of the hand within a desired, 
relatively large area which substantially correspond with the working area 
for a normal working place in a seated position. It is of substantial 
importance that the hand or hands everywhere within this area may rest 
with the entire weight of the forearm and hand on the support. 
Furthermore the support also may completely take over the load in case the 
user should lean forwards, stretch the body etc. thereby transmitting a 
substantial portion of the weight of the upper part of the body to the 
support. Corresponding prior art supports do not exist, whether on the 
market nor in the literature. 
The above mentioned advantages are achieved with the support for the 
forearm according to the present invention as defined by the features 
stated in the claims. 
The support for the forearm according to the present invention can be 
adjusted in the height for optimal adaptation to the user in question, 
allowing turning of the forearm in a plane parallel to the table on which 
the work is performed and to which the support is fixed. A transversal 
movement parallel to the edge of the table and a displacement out from and 
towards the body, as well as combinations of such movements are enabled 
with the inventive support. 
The support for the forearm may be used for one arm alone, such as in 
connection with assembly work, use of a calculator etc., or with one 
support according to the present invention for each arm, whereby the 
distance between the users two arms easily can be adjusted by the user 
when clamping the support correspondingly to the working table.

DETAILED DESCRIPTION OF THE INVENTION 
The support for the forearm according to the present invention comprises a 
resting cushion 8 having a length suitably corresponding to half of the 
length of users forearm and preferably being equipped with an upholstery, 
most suitably covered with leather, in such a way that the forearm 
comfortably rests on the cushion. Suitably the cushion 8 has a bawl shaped 
transversal section as disclosed in FIG. 2. 
The underside of the cushion 8 is secured to a rail well known in the art, 
such as according to the roll on system. Balls 2 are captured in a 
retainer 3 in the entire length of the rail 1 whereby a plate 4 extends 
along the edges outside the rail 1 and being connected with the retainer 
3. The rail 1 extends along substantially the entire underside of the 
cushion 8. Having the fixed plate 4 anchored, the cushion may be displaced 
a length corresponding to the length of the rail 1 and the retainer 3, 
e.g. the length of the cushion, corresponding to distance necessary for 
stretching the arm in the different cases. 
The support of the cushion 8 to the plate 4 is made such that large forces 
and movements may be transferred from the user against the cushion 8 to 
the plate 4, also with the cushion in its end positions. The forces are 
transferred suitably to the underlaying table etc. Suitably a stop 7 is 
provided on the retainer 3 at both ends of the rail. 
A bolt 5 is secured to the plate 4 and vertically threaded into a socket 
arm 6. The plate 4 and thereby also the cushion 8 in this manner may be 
adjusted in the height by turning the bolt 5 in or out of the socket arm 
6. This embodiment additionally provides the user with the possibilities 
in a very simple and secure way to turn the cushion 8 horizontally around 
the bolt, thereby covering a working area corresponding to a circle 
segment which can be moved from a position on the table where the cushion 
is arranged away from the user and to a position where the cushion is 
turned back against the user. 
The end of the socket arm 6 opposite the bolt 5 comprises an upper and a 
lower, horizontal flange between which is mounted an easily rotatably 
clamp 9, preferably with upper and lower ball bearings. The clamp 8 
comprises an upper flange adapted for arrangement on the upper surface of 
a table 14, and a lower flange having a securing bolt 15 for securing the 
clamp 9 to the table. The clamp 9 thereby easily can be secured to the 
edge of a table 14 as disclosed in FIG. 3. 
As also disclosed in FIG. 3 the working area is substantially increased 
when making the socket arm 6 rotatable, in addition to the possible 
rotation of the cushion 8. The cushion 8 may be turned around the axis 11 
of the bolt 5 in the socket arm 6. Furthermore the socket arm 6 itself may 
be turned around the axis 12 at the connection between the clamp 9 and the 
socket arm 6. Suitably the lower flange 13 of the socket arm is extended 
in such a way that its front edge provided an abutment and a stop against 
the clamp 9, thereby limiting the possible rotation angle of the socket 
arm 6, as can be seen from FIG. 3. 
Furthermore the bearing of the socket arm 6 in the clamp 9 may be provided 
with a certain friction to movement to achieve a certain dampening of the 
transversal movement. 
The cushion 8 suitably is concave to provide a comfortable and steady rest 
for the forearm. As disclosed in FIG. 1 the cushion 8 furthermore is 
inclined downwards towards the rail, such as downwards from the user to 
conform with the shape of the forearm, or when turning the cushion 8 to 
conform with special wishes from the user in connection with the work to 
be performed. 
The axis 12 on FIG. 3 is disclosed at a distance outside the abutment of 
the clamp 9 on the table 14. By suitable choice this distance may be 
changed in such a way that the rotation radius of the socket arm may be 
increased or decreased by arranging the axis 12 closer to or further away 
from the table, or even, by a special embodiment, arranging the axis 12 
through the flanges of the clamp 9 and the table as well. 
For suitable arrangement of a working place for a keyboard connected to a 
computer or a type writer, two supports according to the present invention 
are clamped to a table at a distance from each other suitable for the 
user. The length of the upper flange of the clamp 9 suitably has such a 
dimension that the edge of the keyboard may abut against this edge 10. The 
possible movements provided by the support give full availability to all 
the different parts of the keyboard, maintaining full support in the 
entire area. 
Corresponding arrangement of two supports furthermore may be suitable for 
other types of works, such as production works for assembly, soldering 
etc. 
By the use of only one support for the forearm according to the present 
invention a secure support is provided for working places where one hand 
apparatus such as calculators are used during a long period of a working 
day.