[0001] The invention relates to a hinge comprising two parts which are rotatable relative
to one another about an axis of rotation, are united by a continuous hinge pin, and
are provided with a blocking mechanism against rotation by which the rotation angle
is limited to a maximum value. Such a hinge can be used in a wide range of applications
and is highly suitable for furniture such as, in particular, lecture room desk seats
which assume an upright position upon being left by the occupant. The invention also
relates to a lecture room desk provided with a hinge.
[0002] A known hinge of the kind mentioned in the opening paragraph comprises the hinge
pin in the form of an external shaft in the one part, which shaft is received in a
complementary, cylindrical cavity in the other part. The known hinge in addition comprises
two studs on the one part which cooperate with shock absorbers on the other part so
as to form a blocking mechanism against rotation whereby the maximum rotation angle
of the hinge is defined.
[0003] A disadvantage of the known hinge is that the total load on the hinge transverse
to the hinge pin is borne by the comparatively thin shaft. This results in a comparatively
great pressure in the plane of rotation, which intensifies wear. The known hinge is
in addition given a comparatively voluminous construction with the object of making
it withstand loads which are usual in furniture, especially lecture room desks.
[0004] The present invention has for its object to provide a hinge of the kind mentioned
in the opening paragraph in which the load in the hinge is distributed over a larger
supporting surface area, so that the hinge can be more durable and compact.
[0005] According to the invention, a hinge of the kind mentioned in the opening paragraph
is for this purpose characterized in that the hinge pin comprises a flat plate, in
that at least one of the two parts comprises a cavity for receiving said flat plate,
said cavity encompassing a space defined by a rotation of the flat plate through an
angle α smaller than 180° about the axis of rotation, and in that the hinge pin cooperates
with the edge of the cavity at least during operation for forming the blocking mechanism
against rotation. The fiat plate of the hinge according to the invention bears at
least substantially entirely on the edge of the cavity in the case of a load transverse
to the hinge pin. A comparatively large supporting surface is obtained thereby which
effectively distributes the load in the hinge and reduces the pressure on the hinge
pin. The hinge according to the invention as a result is less liable to wear, which
leads to a longer useful life. In addition, the hinge according to the invention may
be of a considerably more compact construction than the known hinge for a given loading
capacity. The compactness of the hinge according to the invention is further promoted
by the fact that the flat plate itself acts as the blocking mechanism in conjunction
with the edge of the cavity, so that no additional space is occupied by separate studs
and shock absorbers as in the known hinge. The invention thus offers a particularly
compact and robust hinge which, moreover, can be manufactured at a comparatively low
cost price on account of its simplicity.
[0006] The angle through which the plate can rotate in the cavity is equal to the angle
α enclosed by the hinge cavity. The rotation angle can be increased through a widening
of the cavity. Widening of the cavity, however, has the disadvantage that the relevant
part of the hinge will become less robust because of the loss of material and the
resulting reduction of the supporting surface of the hinge plate. To counteract this,
a preferred embodiment of the hinge according to the invention is characterized in
that the other part also comprises a cavity for receiving the flat plate therein,
encompassing the space defined by a rotation of the flat plate about the axis of rotation
through an angle β smaller than 180°, and in that the hinge pin is accommodated unconstrained
in both cavities. In this case the hinge pin is rotatable not only through an angle
α in the one part of the hinge, but also through an angle β in the other part. The
total angle of rotation of the hinge is thus given by the sum of the two angles, α
+ β. The angle β may be equal to α, but it may also be chosen to be smaller or greater,
if so desired. If the two angles are the same, a doubling of the angle of rotation
is achieved for a given cavity size and with the supporting surface remaining the
same. The resulting increase in the total rotation angle thus does not detract from
the robustness and durability of the hinge.
[0007] To achieve an optimum distribution of forces, and accordingly a maximum strength,
and also for aesthetic reasons, the cavity has a depth which is at least equal to
the length by which the hinge plate projects from the other part of the hinge. The
torque acting on the hinge is as small as possible then, and the hinge pin is not
visible from the outside.
[0008] The parts of the hinge may be manufactured from any suitable material. To improve
the durability and loading capacity, however, a special embodiment is based on a metal
at least for the hinge pin, said pin in particular being manufactured from steel.
[0009] The parts of the hinge according to the invention can be readily manufactured on
account of their simplicity in usual manufacturing processes such as, for example,
a suitable (die) casting process. The internal strength of the hinge allows for a
particularly compact design. A special embodiment of the hinge according to the invention
is accordingly characterized in that the cavity is formed in a further solid part,
and in that said cavity has a dimension which accounts for at least 75% of an external
dimension of the relevant part. The dimensions of the relevant part are scarcely larger
than those of the cavity then.
[0010] The hinge according to the invention is particularly suitable for applications where
the hinge is loaded transversely to the hinge pin. This is relevant especially in
the case of furniture, and particularly lecture room desks. The invention accordingly
also relates to a lecture room desk comprising a frame and a seat which are interconnected
with rotation possibility by means of a hinge according to the invention, which lecture
room desk according to the invention is further characterized in that the seat extends
over different lengths on either side of the hinge and is provided at the shorter
side with a counterweight for raising the seat into an upright position in the unloaded
state.
[0011] The invention will now be explained in more detail with reference to a few embodiments
and the accompanying drawing, in which:
- Fig. 1
- shows a lecture room desk according to the invention;
- Figs. 2A-2D
- show a first embodiment of a hinge according to the invention as used in the desk
of Fig. 1; and
- Figs. 3A-3F
- show a second embodiment of a hinge according to the invention.
[0012] The Figures are purely diagrammatic and not always true to scale. Some dimensions
are particularly exaggerated for greater clarity. Corresponding parts have been given
the same reference numerals as much as possible in the Figures.
[0013] Fig. 1 shows a lecture room desk according to the invention comprising a frame 1
in which a seat 2 is fastened with hinging possibility. For this purpose, the frame
is mounted on two supports 3 which are each connected to the frame 1 by means of a
hinge 4. The seat here extends on either side of the hinge, the shorter side being
provided with a counterweight 5 for raising the seat into an upright position in the
unloaded state, as shown.
[0014] The parts of the hinge 4 are shown in Figs. 2A-2D in cross-section and comprise two
parts 11, 12, made from aluminium in the present example, which can rotate relative
to one another and are interconnected by a continuous hinge pin 10. In practice, the
first part 11 of the hinge serves as a support for the seat 2, while the other part
12 of the hinge 4 is securely fastened to the frame 1.
[0015] According to the invention, the hinge pin 10 comprises a flat plate which in the
present example is integral with the corresponding part 11 of the hinge 4 and can
rotate freely in a cavity 13 provided in the second part 12 of the hinge 4. The plate
here projects by a length of approximately 35 mm and has a width and thickness of
approximately 30 and 10 mm, respectively. The dimensions and the material of the hinge
pin 10 are thus adapted to a usual load of the hinge in a lecture room desk, but they
may indeed be varied at will without departing from the scope of the invention in
order to, for example, provide an optimum performance in any other specific field
of application.
[0016] The cavity 4 encompasses the shape defined by a rotation of the hinge plate 10 through
an angle α about an axis of rotation 14, a certain clearance being provided for safeguarding
an unhampered rotation of the hinge plate 10. If so desired, the cavity 13 may be
less deep or especially deeper than the length over which the hinge plate 10 extends.
For an optimum distribution of forces and for aesthetic reasons, however, the cavity
is preferably as deep as the length over which the hinge plate 10 projects from the
first part 11 of the hinge. In that case the torque in the hinge is a minimum and
the hinge pin is not visible from the outside. In the present example, the cavity
has a depth of approximately 40 mm, which offers an ample tolerance for accommodating
length variations of the hinge pin 10. The cylindrical parts 15 in which the cavity
13 and the plate 10 are formed in this example have an external diameter of approximately
40 mm and are thus hardly any bigger than the hinge cavity 13 as far as the diameter
is concerned. This renders the hinge extremely compact in comparison with known hinges
with the same or a similar loading capacity.
[0017] The shape and dimension of the cavity imply that the maximum angle of rotation of
the plate 10 therein is substantially equal to α. Figs. 2C and 2D show the two parts
11, 12 united so as to form the hinge, with the hinge 4 drawn in its extreme positions,
the angle α of approximately 81° in this case being indicated. In these extreme positions,
the hinge plate 10 cooperates with the edge 16 of the cavity 16 so as to form a blocking
mechanism against rotation, whereby the rotation angle is limited to the value α.
If so desired, shock absorbers may be mounted in the cavity for damping the impact
of the hinge. The maximum angle of rotation will be somewhat smaller than α then,
depending on the thickness of the shock absorbers used.
[0018] Since the hinge plate 10 in the extreme positions of the hinge bears on the edge
16 of the cavity with a major portion of its surface area, the forces arising therein
transversely to the hinge plate 10 are distributed over a comparatively large surface
area. The loading capacity of the hinge according to the invention is as a result
comparatively high in a relatively compact embodiment already. This is advantageous
especially in the case of furniture, where the outward appearance of the hinge may
play a major role.
[0019] A preferred embodiment of the hinge according to the invention is shown in Figs.
3A-3F, where Figs. 3A-3D show the hinge parts individually and Figs. 3D-3F show the
hinge parts assembled together. In contrast to the embodiment described above, the
hinge plate 10 here is not integral with one of the two parts 11, 12 of the hinge,
but instead both parts have a respective cavity 13, 13' in which a separate, loose
hinge plate 10 is freely accommodated. The hinge plate 10 has a length, width and
thickness of 70, 30 and 10 mm, respectively and is made from steel for a better load
resistance. The two other parts 11, 12 of the hinge comprise aluminium, as in the
previous example.
[0020] According to the invention, the two cavities 13, 13' substantially encompass the
space defined by a rotation of the hinge plate 10 through angles α and β about the
axis of rotation 14, the cavities again being designed a little wider to provide the
clearance necessary for the hinge plate 10. The two angles α, β, and thus the cavities
13, 13' may be chosen to be the same, as in the present example, but they may alternatively
be mutually different, if so desired. In this example the angles α, β each have a
value of approximately 40.5°.
[0021] An advantage of this embodiment over the preceding one is that the total angle of
rotation of the hinge is formed here by the sum of the angles α and β, and is accordingly
doubled in the present case to a value 2α. This is diagrammatically depicted in Figs.
3D-3F. The hinge is in a first extreme position in Fig. 3D. Fig. 3E shows an intermediate
position in which the plate 10 has rotated through the angle β in the cavity 13' of
the first part. In Fig. 3F, the plate has also rotated in the cavity 13 of the second
part 12 through the full angle α, and the hinge is in the other extreme position in
which the two parts have rotated relative to one another through a total angle α +
β of approximately 81°. The angle of rotation has thus been doubled in this example
with the two angles α, β being the same for a cavity 13, 13' of the same size as in
the preceding example. The surface area of the edge 16 of the cavity 13, 13', and
thus the supporting surface of the hinge plate have become larger thereby, which results
in a greater loading capacity of the hinge for the same external dimensions. A particularly
compact, robust and durable hinge is thus realized which can be loaded up to a comparatively
high value transversely to the hinge pin 10 and is accordingly highly suitable for
use in furniture, and especially in lecture room desks.
[0022] Although the invention was discussed in detail above with reference to only two embodiments,
it will be obvious that the invention is by no means limited to the examples given.
Many more variations and modifications are indeed possible to those skilled in the
art within the scope of the invention. Alternative materials may thus be used for
the hinge parts, while the parts need not all be manufactured from the same material,
but a material may be chosen for each part which is ideally adapted to the specific
function and load of the relevant part. Furthermore, the hinge according to the invention
may be used not only in lecture room desks but also in other furniture such as, for
example, collapsible table legs or arm rests; indeed, the invention is not limited
to furniture at all but may be applied to all cases where parts are hinged together
and their angle of rotation is limited to a predetermined maximum value.
1. A hinge comprising two parts which are rotatable relative to one another about an
axis of rotation, are united by a continuous hinge pin, and are provided with a blocking
mechanism against rotation by which the rotation angle is limited to a maximum value,
characterized in that the hinge pin comprises a flat plate, in that at least one of
the two parts comprises a cavity for receiving said flat plate, said cavity encompassing
a space defined by a rotation of the flat plate through an angle α smaller than 180°
about the axis of rotation, and in that the hinge pin cooperates with the edge of
the cavity at least during operation for forming the blocking mechanism against rotation.
2. A hinge as claimed in Claim 1, characterized in that the other part also comprises
a cavity for receiving the flat plate therein, encompassing the space defined by a
rotation of the flat plate about the axis of rotation through an angle β smaller than
180°, and in that the hinge pin is accommodated unconstrained in both cavities.
3. A hinge as claimed in Claim 1 or 2, characterized in that the cavity has a depth which
is at least equal to the length by which the hinge plate projects from the other part
of the hinge.
4. A hinge as claimed in Claim 1, 2 or 3, characterized in that at least the hinge pin
of the hinge comprises a metal, and in particular is manufactured from steel.
5. A hinge as claimed in any one of the preceding Claims, characterized in that the cavity
is formed in a further solid part in at least one of the two parts, and in that said
cavity has a dimension which accounts for at least 75% of an external dimension of
the relevant part.
6. A lecture room desk comprising a frame and a seat, characterized in that the frame
and the seat are interconnected by means of a hinge as claimed in any one or several
of the preceding Claims, and in that the seat extends over a different length on either
side of the hinge and is provided at the shorter side with a counterweight for raising
the seat into an upright position in the unloaded state.