[0001] The present invention relates to a device enabling the door panel of a cold room
sliding door to be released from its closed position.
[0002] As known to the expert of the art, doors of this type comprise a door panel sliding
on guides disposed parallel to the wall in which the door aperture is provided. These
door panel guides are shaped such that when the door panel is moved from its maximum
open position (which leaves the entire aperture uncovered) to its closed position,
just before it reaches this latter position the door panel is made to approach the
wall and floor such that these press against the gaskets, carried by the door panel,
which ensure the seal.
[0003] These doors are provided with a device which enables the door to be easily released,
and which levers against one side of the door aperture (normally against the relative
upright of the frame defining the door aperture) so as to withdraw the door panel
from this upright by overcoming both the opposing resistance and friction, also exerted
by said seal gasket when in its compressed state.
[0004] As also known to the expert of the art, a known device of this type comprises:
- a bush having a length substantially equal to the door panel thickness in order to
be able to be incorporated into the door panel with its axis perpendicular thereto,
the bush laterally presenting at least two opposing through slots, the axes of which
must have their inclination opposite the bush axis, with the inclination of the slot
axes in a door with rightward opening being opposite that of a door with leftward
opening;
- a central shaft coaxially inserted into the bush such that it can be rotated about
its axis and be moved along said axis, and of which the length enables it to project
from both sides of the door panel;
- a number of pawls projecting radially from said central shaft equal to the number
of slots provided in said bush, each pawl engaging in a relative slot;
- an external handle, consisting of a rather lengthy bar (even more than 50 cm) fixed
to the outer end of the central shaft and extending radially from it (normally disposed
vertically downwards when the door is closed);
- an internal handle, consisting of a lever fixed to the shaft and which, with the door
closed, extends both upwards and downwards from the central shaft (which forms its
fulcrum), the free end of its upper part being deviated to the left if the door is
of rightward opening type and to the right if of leftward opening type, such that
with the door closed, this free end rests against the vertical upright of the door
frame;
- a preloaded helical spring, mounted coaxially on the central shaft such that one end
rests on a relative shoulder provided inside the bush, while the other end of the
spring rests on a collar provided on the central shaft, the spring maintaining the
shaft-handle assembly in a position withdrawn outward from the door panel when this
latter has been released, so as not to interfere with said gaskets when the door is
completely opened.
[0005] Essentially, by simply rotating the external handle anticlockwise if the sliding
door opens rightwards or clockwise if it opens leftwards, and consequently causing
the internal handle to rotate and act as a lever with its upper end acting against
the door frame, the aforedescribed device releases the door panel when in its closed
position. Once released, the door panel can be manually moved until the door is completely
open.
[0006] In contrast, after then manually sliding the door panel into its closed position,
as the shaft-handle assembly (because of the action of said helical spring) is still
in its rotated and withdrawn position because of having previously opened the door,
the upper end of the internal handle rests against the relative upright of the door
frame before the door panel arrives in its completely closed position. Completing
closure of the door panel causes the internal handle to rotate (viewing from the outside)
and to move inwards, against the action of the helical spring, until the shaft-handle
assembly assumes the already described closed position.
[0007] It has already been stated that in the case of a door with leftward opening, the
bush must have its slot inclination opposite that of a bush for rightward opening
doors. The aforedescribed internal handle is also different (specular) in the two
cases, although it can be easily produced such as to be able to be fixed to the central
shaft in a determined position compatible for example with rightward opening and also
in an inverted position to be also compatible with leftward opening.
[0008] It should also be noted that door panels for cold rooms can have different thicknesses
(in particular thicknesses of 70, 80, 90, 100 and exceptionally 120 mm), so that the
current manufacturers of devices of this type have to produce bushes of the corresponding
length (bushes of five different lengths in the specific case of the aforesaid thicknesses),
but for each bush length two bushes have to be produced having opposingly inclined
slots, for rightward opening and leftward opening doors. Hence a cold room sliding
door manufacturer must currently stock ten different bush types.
[0009] An object of the present invention is therefore to provide a device of the aforesaid
type which is adaptable to all or at least a part of the currently required door panel
thicknesses for doors of this type.
[0010] This object is attained by the device of the present invention for rightward opening
or leftward opening sliding doors, comprising:
- a bush incorporated into the thickness of the door panel and fixed thereto such that
its axis is perpendicular to the door panel;
- a central shaft coaxially inserted into the bush to be able both to rotate about the
axis of this latter and to move along said axis;
- means for guiding the movement and rotation of the central shaft, which enable it
to rotate in the direction compatible with the door opening direction;
- elastic means to bring the central shaft into a position withdrawn outwards from the
door panel when left free to move coaxially;
- external means for rotating the central shaft;
- internal means for rotating the central shaft and provided with a striker adapted
to come into contact with a fixed point (for example the relative side of the door
frame) such that, following forced rotation, achieved by said external or internal
means, of the central shaft in the direction compatible with the door opening direction,
a consequent forcing of said striker against said fixed point is obtained, such as
to cause release of the door,
characterised in that the bush has a length less than the thickness of all or at least
part of the door panels of such doors, a ring cap being provided coupleable coaxially
to the bush such that the bush-ring cap assembly has a length adapted to the thickness
of the specific door panel.
[0011] According to one embodiment of the present invention, the coupling between the ring
cap and bush is of "telescopic" type, means (in particular screws) being provided
to fix the ring cap to the bush such as to obtain the required length of the bush-ring
cap assembly.
[0012] Said guide means for the central shaft can in particular comprise two opposing guides
provided in the inner wall of the bush, the guides having an inclination to the bush
axis which is compatible with the door opening direction, these guides cooperating
for this purpose with respective pawls projecting radially from the central shaft.
[0013] Another object of the present invention is to provide a device of the aforesaid type
which besides being adaptable to all or at least part of the commercially required
door panel thicknesses is usable for both rightward opening and leftward opening sliding
doors.
[0014] This object is also attained by the device of the present invention in which, provided
in one and the same bush, there are both first guide means for the central shaft which
enable it to rotate in the direction corresponding to a door with a determined opening
direction, and second guide means which enable the central shaft to rotate in the
opposite direction corresponding to the opening direction of a door with opposite
opening direction.
[0015] This can be easily achieved for example by providing in the bush interior two first
opposing guides which extend with an inclination to the bush axis which is compatible
with a door having a determined opening direction, and two second opposing guide means
which extend with an inclination compatible with the other opening direction, with
the result that the first guides have the opposite inclination to the two second guides.
[0016] In particular, the guide means can have a fixed limit stop corresponding to the angular
position of the central shaft relative to the released door panel, the other limit
stop being removable and positionable, depending on whether the door has rightward
opening or leftward opening, to operate as a limit stop for rightward opening or leftward
opening guide means respectively.
[0017] The invention will be more easily understood from the following description of one
embodiment thereof given by way of example. In this description reference is made
to the accompanying drawings, in which:
Figure 1 is an exploded perspective view of a device according to the present invention;
Figure 2 is a second exploded perspective view thereof, but from another viewpoint;
Figure 3 is a rear view, with reference to Figure 1, of the bush shown in that figure;
Figure 4 is a section therethrough taken on the line 4-4 of Figure 3;
Figure 5 is a section therethrough taken on the line 5-5 of Figure 3;
Figure 6 is a rear view, again with reference to Figure 1, of the ring cap visible
in that figure;
Figure 7 is a section therethrough, taken on the line 7-7 of Figure 6;
Figure 8 shows in the right part an enlarged plan view from above of the central shaft
visible in Figure 1, and in the left part a horizontal coaxial section therethrough;
Figure 9 is a partly sectioned lateral view thereof in the direction of the arrow
9 of Figure 8;
Figure 10 is a perspective view of the external handle as it appears once applied
to a cold room sliding door panel (shown partially) with leftward opening;
Figure 11 is a perspective view of the internal handle applied to the same door panel.
[0018] As can be seen in Figures 1 and 2, the device shown therein, indicated overall by
10, comprises a bush 12, shown in greater detail in Figures 3-5, and a ring cap 14
to be mounted coaxially on the bush 12 and fixed thereto by (in the specific illustrated
case) three screws insertable through corresponding through holes provided in the
ring cap 14, the screws 16 being insertable through relative holes 17 and screwed
into threaded holes 18 provided in the bush 12. As can be seen from Figures 1 and
2, an entire set of holes 18 is provided to enable, by means of a type of telescopic
joint, the overall length of the bush-ring cap assembly to be adjusted to adapt it
to the thickness of the specific sliding door panel to which the device 10 is to be
applied. It has already been stated, by way of example, that doors are currently available
having thicknesses of 70, 80, 90, 100, 120 mm, so that the position of the holes 18
on the bush 12 in the axial direction is chosen such that the length of the bush 12-ring
cap 14 assembly is compatible with said door panel thicknesses. In fact, by virtue
of the device of the present invention, doors can be formed having door panels with
a larger range of thicknesses, i.e. thicknesses much closer to specific requirements
(for example a series of thicknesses differing from each other by 5 mm).
[0019] The device 10 also comprises a central shaft 20 (Figures 1, 2, 8 and 9) inserted
coaxially into the bush 12-ring cap 14 assembly such that it can rotate about its
own axis, but also translate in both directions along this axis. As best seen in Figures
8 and 9, the central shaft 20 presents a diametrical through hole 22 arranged to receive
a diametrical pin 24 the two ends of which project equally from the central shaft
20 to form two respective pawls (indicated for simplicity by the same reference numeral
as the pin 24) which cooperate with corresponding guides (described below) formed
by recesses provided in the interior of the bush 12. These guides consist essentially
of one of the edges of a relative recess, this edge being inclined to the axis of
the bush 12. One of the two guides, indicated by 26, is visible in Figure 4. The relative
pawl 24 rests against this guide. It should be noted that the guide 26 is suitable
for a sliding door with leftward opening. The other pawl 24 is guided by a similar
edge of a corresponding recess (not visible in the figures because it is opposite
that of the guide 26, it being inverted to be able to perform the same function when
the central shaft 20 is rotated in the anticlockwise direction with reference to Figure
1).
[0020] It should be noted that the same bush 12 also presents at the same time a second
pair of opposite guides suitable for a rightward opening door. The guides of this
second pair are disposed rotated through 90° to those of the first pair and have opposite
inclination. A guide of the second pair, indicated by 27, is visible in Figure 5.
[0021] The device 10 also comprises a helical spring 28 which when the device 10 is mounted
is preloaded and rests with one end on a collar 30 of the central shaft 20 whereas
its other end rests against the step 32 in the interior of the bush 12.
[0022] Once a door, for example with leftward opening, has been released, the spring 28
causes the central shaft 20 to withdraw outwards until the two pawls 24 abut against
the two stop elements 36 fixable to the bush 12, this latter presenting for this purpose
two relative seats 38 (also see Figure 3). The arched arm of the stop elements 36
enables the movement of the relative pawl 24 along the guide 26 to be also limited
from the other side. It should be noted that by simply inverting the stop elements
36, these no longer interfere with the pawls 24 of the first pair, but instead interfere
with the said pawls 24 when cooperating with the second pair of guides (those for
a leftward opening door) Consequently, by simply orientating the bush 12 angularly
in a suitable manner and fixing the stop elements 36 to the bush 12 in accordance
with that of their two possible positions which corresponds to this orientation, the
device 10 can be adapted to a door with rightward opening rather than with leftward
opening.
[0023] From Figures 1 and 2 it can be seen that the device 10 also comprises two covers
40 and 42 positioned on the inside of the door panel, which are used to fix the bush
12-ring cap 14 assembly to the door panel, and also an external handle 44 and an internal
handle 46. The external handle 44 is fixed to one end of the central shaft 20 by simply
inserting its near end into the dead hole 48 provided in the central shaft 20, to
then lock it in position with a screw 50, whereas the internal handle 46 is fixed
to the central shaft 20 by a form fit (not visible completely, but of conventional
type) and two screws (of which for simplicity only one, indicated by 52, is shown
in Figures 1 and 2). It can be seen from Figure 1 that the internal handle 46 is essentially
a lever with its fulcrum corresponding to the axis of the central shaft 20, there
also being present (also see Figure 11) a hammer head 54 arranged to abut against
the relative upright (not shown) of the frame bounding the door, whether rightward
opening or leftward opening. It can also be seen that the internal handle 46 has a
rectangular cross-section with its minor sides parallel to the axis of the central
shaft 20, in order that the thickness of this handle in the direction perpendicular
to the door panel is not such as to interfere, during door opening, with the frame
of this latter.
[0024] The operation of the device 10 is also apparent to an expert of the art from the
aforegoing. It will however be briefly described for greater clarity with reference
to a leftward opening door, the operation of a rightward opening door being consequently
evident.
[0025] When the door is closed, the external handle 44 and internal handle 46 lie in a vertical
position with the left end of the hammer head 54 close to the right upright (not shown)
of the door frame (or other suitable fixed point). In this situation the pawls 24
rest in the groove 34 (Figure 4) and the spring 28 is in its minimum compression condition.
[0026] To release the door from the outside the external handle 44 has to be rotated clockwise,
this causing the door panel to move towards the left and, because of the shape of
the relative guide, to withdraw such that it can be opened without the door panel
seal gaskets interfering with the door frame. By virtue of the guides 26, rotating
the handle 44 causes the pawls 24 to move along the relative guides 26 until the pawls
24 become positioned against the limit stops 36. If the handle 44 is left free at
this point, the action of the spring 28 returns the pawls 24 into the corresponding
grooves 34, the handle 44 consequently returning into the vertical position (withdrawn
position, so that it does not interfere with the door frame when the door is opened
completely, such that the entire door aperture is usable).
[0027] To close the door, the door panel needs merely to be returned to its closed position.
[0028] In conclusion, by virtue of the device of the present invention, only one set of
pieces needs to be stocked for the device 10, and in particular only one bush 12 for
an entire series of door panel thickness for the cold room sliding door, whether the
door is rightward opening or leftward opening.
1. A device (10) for releasing a door panel (56) of a cold room sliding door from its
closed position, comprising:
- a bush (12) incorporated into the thickness of the door panel (56) and fixed to
the door panel (56) such that its axis is perpendicular to this latter (56);
- a central shaft (20) coaxially inserted into the bush (12) to be able both to rotate
about the axis of this latter (12) and to move along said axis;
- means (26, 24; 27, 24) for guiding the movement and rotation of the central shaft
(20), which enable it to rotate in the direction compatible with the door opening
direction;
- elastic means (28) to bring the central shaft (20) into a position withdrawn outwards
from the door panel (56) when left free to move coaxially;
- external means (44) for rotating the central shaft (20);
- internal means (46) for rotating the central shaft (20) and provided with a striker
(54) adapted to come into contact with a fixed point such that, following forced rotation,
achieved by said external means (44) or internal means (46), of the central shaft
(20) in the direction compatible with the door opening direction, a consequent forcing
of said striker (54) against said fixed point is obtained, such as to cause release
of the door; characterised in that the bush (12) has a length less than the thickness of all or at least part of the
door panels (56) of such doors, a ring cap (14) being provided coupleable coaxially
to the bush (12) such that the bush (12)-ring cap (14) assembly has a length adapted
to the thickness of the specific door panel (56).
2. A device as claimed in claim 1, wherein the coupling between the ring cap (14) and
bush (12) is of "telescopic" type, means (16) being provided to fix the ring cap (14)
to the bush (12) such as to obtain the required length of the bush (12)-ring cap (14)
assembly.
3. A device as claimed in claim 1, wherein the guide means for the central shaft (20)
comprise two opposing guides (26; 27) provided in the inner wall of the bush (12),
and respective pawls (24) projecting radially from the central shaft (20) and cooperating
with the guides (26; 27), these latter (26; 27) having an inclination to the bush
(12) axis which is compatible with the door opening direction.
4. A device as claimed in claim 1, wherein provided in one and the same bush (12) there
are both first guide means (26, 24) for the central shaft (20) which enable it to
rotate in the direction corresponding to a door with a determined opening direction,
and second guide means (27, 24) which enable the central shaft (20) to rotate in the
opposite direction, corresponding to the opening direction of a door with opposite
opening direction.
5. A device as claimed in claim 4, wherein the first and second guide means for the central
shaft (20) comprise respectively two first guides (26) and two second guides (27)
provided in the inner wall of the bush (12), the angular position of the second two
guides (27) being rotated through 90° to those of the first two guides (26).
6. A device as claimed in claim 3 or 5, wherein the guides (26; 27) have a fixed limit
stop (34; 35) corresponding to the angular position of the central shaft (20) relative
to the blocked door panel (56), the other limit stop (36) being removable and positionable,
according to whether the door has rightward opening or leftward opening, to operate
as a limit stop for rightward opening guide means (27, 24) or leftward opening guide
means (26, 24) respectively.
7. A device as claimed in claim 1, wherein the external means and the internal means
for rotating the central shaft (20) comprise respective manually operable levers (44,
46).
8. A device as claimed in claim 7, wherein the internal lever (46) is pivoted at an intermediate
point thereof and fixed at that point to the central shaft (20), that end of the internal
lever (46) opposite the gripping end presenting a striker (54) of hammer head shape
intended to come into contact with the fixed striker point, on one side or the other,
depending on the door opening direction.