[0001] European patent application Nr. 84201887 to the same owner, discloses a structural
shape made from a substantially rigid plastic material for refrigertaor cabinets,
or the like, wherein the door of the cabinet comprises a counter-door, with said structural
shape bearing a bellows-like acting gasket made from a substantially less rigid material,
which accomplishes a tight sealing between the door and the cabinet, with the structural
shape and the gasket being suitably coupled with each other, or manufactured as one
single piece by means of the co-extrusion of said materials of different stiffness,
so as to make it possible the gasket, which is less rigid, to be quickly detached
from the structural shape, whichs is more rigid, along the region of their mutual
connection.
[0002] According to said European patent application, the structural shape is provided,
on its side destined to be placed in a position opposite to the cabinet when in use,
with two flat faces between which a groove is defined, which is suitable for receiving
a spare gasket The structural shape is provided, along at least one of its sides,
with an elastically yielding side flange, which acts as a spring in order to provide
a snap-coupling with the counter-door, during the step of components assemblage.
[0003] The object of the present invention is substantially an improvement of the structural
shape as disclosed in said European patent application.
[0004] In particular, a first purpose of the present invention is to improve in a decidedly
advantageous way the structure of the spring which is used in order to fasten the
structural shape to the counter-door. In fact, it is well known that in the hereinabove
briefly mentioned structural shapes known from the prior art, totally made from a
rigid material, it is of basic importance to obtain a very good elasticity of the
spring, which must yield under the pressure applied by the counter-door during the
assemblage step, and then elastically return - once that said pressure is relieved
- to spring-like lock the edge of said counter-door. In order to obtain these characteristics,
it is necessary to give the structural shape a suitably thin thickness in its region
of the fulcrum of the spring.
[0005] However, during the manufacturing of the components, which takes place by extrusion
through a die, such a thickness of the structural shape in that critical region can
begin to vary, and, in particular, to increase, owing to a progressive wear of the
die caused by the friction of the material flowing inside it. An increase in the thickness
of the structural shape of even some fractions of a tenth of a millimiter can cause
a loss in spring elasticity, and therefore problems during the assemblage step, in
particular if the counter-door has a low thickness,
because in that case the spring may not adequately yield under the thrust applied by said
counter-door Therefore, in order to continue to obtain with precision, and constant,
the prefixed shape and thickness of the structural shape, a periodical and careful
maintenance of the die is necessary.
[0006] In order to solve this problem, and achieve further advantages as regards both the
production and the use of the structural shape in question, advantages which will
be clear from a reading of the following disclosure, the present invention proposes
a structural shape made from a substantially rigid material for refrigerator cabinets
and the like, in which the door of the cabinet comprises a counter-door, with said
structural shape bearing a tubular bellows-like gasket made from a substantially soft
material, which accomplished a tight sealing between the door and the case of said
cabinet, with the structural shape and the gasket being suitably coupled with each
other, or manufactured as one single piece by means of the co-extrusion of said substantially
rigid and said substantially soft materials, with said structural shape being provided
with at least one side, elastically yielding flange which acts as a spring in order
to accomplish a snap-coupling with the counter-door during the step of components
assemblage, characterized in that in said side flange the fulcrum of the spring is
constituted by an elbow-shaped insert of said substantially soft material fabricated
inside the substantially rigid material the structural shape is made from.
[0007] The structural shape is made, e.g., from rigid PVC; the gasket, the insert of the
structural shape which acts as the fulcrum of the spring, and the other soft parts
are made from soft, plasticized PVC.
[0008] In order to better understand the characteristics and the advantages of the present
invention, hereinunder an example of non-limitative practical embodiment thereof is
disclosed, by referring to the figures of the hereto attached drawings.
Figure 1 shows a perspective view of a structural shape according to the invention
in combination with the other components it is destined to cooperate with, before
the assemblage.
Figure 2 shows a view similar to that of Figure 1, after that the assemblage is carried
out.
Figure 3 shows a sectional view along the path III-III of Figure 2.
Figure 4 shows a sectional view similar to that of Figure 3, wherein the original
gasket is replaced by a spare gasket.
[0009] Referring to the figures, a structural shape 1 according to the present invention
has a complex cross-section, which on its side which, in its operating position (Figure
3), is opposite to the case 17 of a refrigerator cabinet, has two faces 3 and 5 substantially
planar an extending on mutually staggered planes. The face 5 and with a side tight-sealing
stripe 15, and the face 3 is provided with a tight-sealing stripe 4, with both of
said stripes being made from a soft material, co-extruded with the rigid material
of the structural shape. In an intermediate position between the faces 3 and 5, the
cross-section of the structural shape 1 takes an irregular-"T" shape due to the effect
of a rib 18 which extends
verifically in the direction opposite to the direction towards the cabinet 17, assuming a configuration
slightly bent outwards. From the end of said rib 18, a side flange 7 extends in the
direction of the face 5, with said side flange 7 being elastically yielding as a spring
around a fulcrum 8, which is constituted by an elbow-shaped insert made from a soft
material co-extruded with the rigid material which constitutes the structural shape.
[0010] The side flange 7 ends with a groove-shaped configuration 19, having a "C"-shaped
cross-section ending with a tooth 41 suitable for getting engaged with the counter-door.
[0011] On the opposite side of the structural shape, i.e , that structural shape side which
is opposite, in the operating position, to the cabinet, from the face 3 a flange 9
extends laterally, with said flange 9 being directed otwards and inclined towards
the door of the cabinet. Such a flange 9 ends with a tooth 10. Between the face 3,
the flange 9 and the tooth 10, a groove 23 is thus defined.
[0012] The structural shape 1 is made from a rigid plastic material, e.g., PVC, fabricated
by extrusion, cut and welded in correspondence of the corners, so to form a frame
which reproduces the perimetrical outline of the door of the refrigerator cabinet
onto which it has to be applied.
[0013] Together, and as an enbloc, with the structural shape 1, also a gasket 20, of soft
plasticized PVC, is fabricated by co-estrusion
[0014] The gasket 20 has a tubular cross-section which defines a chamber 21 acting as a
bellows, and a seat 22 suitable for receiving a bar of a magnetic material. The inner
side wall, indicated by the reference numeral 6, of the gasket 20, is bonded to the
face 5 of the structural shape in correspondence of the co-extrusion region 13, and
the external side wall, indicated by the reference numeral 16, is bonded to the side
flange 9 of the structural shape along a junction region 12. The configuration of
the lower portion of the external side wall 16 of the gasket (a wall which can be
suitably differentiated into two regions of different thickness, or of different stiffness,
in order to give lateral stability to the same wall), is characteristic according
to the herein exemplified form of practical embodiment of the present invention: in
fact, the wall 16 extends downwards beyond the region 12 of junction with the structural
shape, ending with a foot 2 which comes to rest against the counter-door when the
parts are assembled in their operating position, so as render the structural shape
1
not any longer visible in such a position.
[0015] The tight-sealing stripes 4 and 15 represent gaskets for containing the material
foamed during the foaming operation which is carried out at the end of the assemblage
step, in order to endow the door with heat-insulating characteristics. The stripe
15 is so made, as to provide a tight sealing, compensating for the distance between
the face 5 of the structural shape and the counter-door 31, between which an air gap
40 is defined, in order to leave a free room for the elastic return of the tooth 41
of the side flange 7, and make easier the movement of engagement of said tooth on
the counter-door.
[0016] The tight-sealing stripe 15 serves to facilitate such a movement of the side flange
7, because it preserves the distance between the face 5 of the structural shape and
the counter-door 31, leaving a free clearance for the tooth 41 to move inside the
air gap 40.
[0017] In the example shown in the Figures, in this case the mutual alignment of the door
and of the counter-door in their end positions, at the end of the assemblage, is secured
by the positioning of the faces 3 and 5 of the structural shape on two staggered planes.
In fact, the air gap 40 on the inner side of the structural shape is compensated for
by the position at a lower height of the face 3 relatively to the face 5. However,
in general it is not necessary that the door and the counter-door are positioned at
a same level.
[0018] For the installation, the structural shape 1 bearing the gasket 18 is suitably prearranged
in a frame shape, and in this form is it supplied to the manufacturer of the refrigerator
cabinet; as Figures 1 and 2 schematically show, said manufacturer can assemble, in
one operation only, the door 30 of steel sheet with the counter-door 31 of plastic
material, by snapwise (spring-like) inserting the structural shape 1, which gets
interlocked with the counter-door thanks to the action of the side flange 7, which
behaves as a spring.
[0019] The structural shape 1 is made move downwards, e.g , by means of a suitable mechanical
arm, towards the counter-door 31, e.g , suitably positioned on a support which keeps
it blocked. As soon as the arm of the side flange 7, in the initial position shown
in Figure 1, and shown in chain in Figure 3, comes into contact with the edge of the
counter-door 31, by being urged by the thrust applied by this latter yields and starts
elastically bending inwards, as a spring, around he fulcrum 8, which is considerably
flexible. When the stroke of the yielding arm of the side flange 7 along the edge
of the counter-door 31 is ended, and this latter has come to the level of the groove
19, the flange 7 goes off owing to the effect of its elastic return, and engages the
edge of the counter-door 31, locking it.
[0020] The so-assembled structural shape 1 and the counter-door 31 are then leant on the
door 30, and the whole is blocked by carrying out the foaming inside the air gap 32.
[0021] As Figure 4 shows, when the soft co-extruded gasket 20 deteriorates due to wear,
a rapid replacement can be carried out by tearing it off along the regions 12 and
13 of junction with the structural shape, and inserting a new gasket 33 inside the
groove 23. Such a spare gasket of soft PVC is characterzied by a base 34 from whose
external side end a vertical foot 35 extends. From the end of this latter foot, a
wedge-shaped foot 11 of co-extruded rigid PVC, ending with a tooth 14, extends in
the direction of the groove 23 of the structural shape. For the replacement, from
the initial position shown in chain in Figure 4, the gasket 33 is inserted laterally
by causing the rigid wedge 11 to slide along the door 30, and pushing. In this way,
under the thrust applied by the wedge, the flange 9 elastically opens wide by a short
distance receiving the tooth 14, which, by stopping against the tooth 10 of the structural
shape, fastens the spare gasket in its position.
[0022] In general, the advantages and the improvements which can be obtained with the structural
shape according to the instant invention are many: first of all, the accomplishment
of the spring which snapwise engages the counter-door - with the fulcrum being constituted
by a co-extruded insert made from a soft material - makes it possible a high flexibility
of said spring to be attained, with no need for its thickness to be reduced and measured
with precision.
[0023] In fact, the elbow-shaped insert makes it possible approximately the same flexibility
of the spring to be obtained, which one would have in a structural shape entirely
consisting of a rigid material in case the fulcrum thickness of this latter was approximately
equal to half of the thickness of the insert according to the present invention.
[0024] Therefore, the very advantageous result is obtained, that a high thickness can be
maintained in the structural shape in that critical region, without it being necessary
said thickness to be constantly monitored owing to the wear of the die, which, in
fact, in case of present invention, does not have any appreciable influence on the
flexibility of the spring. Furthermore, having the possibility of maintaining high
the value of the thickness of the bending region of the spring means a higher mechanical
strength of the component.
[0025] A further advantage of the present invention is accomplished, according to a form
of practical embodiment thereof, thanks to the extended structure of the external
side wall of the bellows of the gasket which - as seen - comes to rest against the
counter-door, so as to render not any longer visible the flat face of the rigid structural
shape.
[0026] This is an advantage, in that it is rather difficult to succeed in obtaining the
same colour shade in the rigid structural shape, and in the soft gasket. Different
colour shades visible in the assembled structural shapes are rejected by the users,
and are therefore a cause of scrap in production
[0027] Inasmuch as, according to the above mentioned form of practical embodiment of the
present invention, the rigid structural shape (see Figures 3 and 4) remains completely
hidden when is assembled on the refrigerator, it can be suitably manufactured from
a non-coloured material, with a strong reduction in the added costs, and in production
scraps
[0028] In such case, the changes in colour will only affect the gasket, which remains he
only component in view after the end of the assemblage.
[0029] A further advantage derives from the operation of replacement of the original gasket
with the spare gasket, which can be obtained thanks to the herein exemplified form
of practical embodiment of the sructural shape.
[0030] In fact, the insertion of the spare gasket takes place laterally in the purposely
provided external groove with which the structural shape is provided. Such a groove
remains hence in a free and accessible position, ideal for being able to receive,
during the manufacturing step, a male element acting as a gauge for maintaining constant
its shape, as well as its distance from the door plane. Such a feature is very useful
in order to make it possible said groove - which must receive the rigid interlocking
wedge the spare gasket is provided with - to be correctly and constantly dimensioned,
preventing any risks that difficulties may be met when this latter is inserted, in
case the groove is too narrow, or an excessive backlash exists, in case the groove
is too wide.
1. Structural shape made from a substantially rigid material for refrigerator cabinets
and the like, in which the door of the cabinet comprises a counter-door, with said
structural shape bearing a tubular bellows-like gasket made from a substantially soft
material, which accomplishes a tight sealing between the door and the case of said
cabinet, with the structural shape and the gasket being suitably coupled with each
other, or manufactured as one single piece by means of the co-extrusion of said substantially
rigid and said substantially soft materials, with said structural shape being provided
with at least one side, elastically yielding flange which acts as a spring in order
to accomplish a snap-coupling with the counter-door during the step of components
assemblage, characterized in that in said side flange the fulcrum of the spring is
constituted by an elbow-shaped insert of said substantially soft material fabricated
inside the substantially rigid material the structural shape is made from.
2. Structural shape according to claim 1, characterized in that it has a substantially
irregular-"T"-shaped cross-section, determined by a couple of flat faces and a intermediate
rib, from which said side flange extends.
3. Structural shape according to claim 2, characterized in that from each one of said
flat faces tight-sealing stripes made from a soft material extend.
4. Structural shape according to claim 3, characterized in that the tightly-sealing
stripe extending from the flat face of the structural shape, which, in its operating
position, is directed towards said counter-door, acts as a spacer for keeping the
structural shape spaced apart from the plane of the counter-door, thus defining an
air gap inside which the movement of coupling of said side flange with said counter-door
takes place freely.
5. Structural shape according to claim 1, characterized in that said structural shape
ends, on its side operatively directed towards the outside of the cabinet on which
it is assembled, with a side flange provided with fastening means, with a seat being
defined between the structural shape and the side flange, which seat is destined to
receive a spare gasket made from a substantially soft maerial, suitably provided with
a hooking means for being hooked to said side arm.
6. Structural shape according to claim 4, characterized in that said spare gasket
is provided with a hooking means which is constituted by a wedge-shaped foot ending
with an interlocking tooth.
7. Structural shape according to claim 6, characterized in that said wedge-shaped
foot is made from a co-extruded, substantially rigid material.
8. Structural shape according to claim 1, characterized in that in said gasket the
external side wall extends beyond the region of junction to the structural shape with
a foot which, in its operating position, come to rest against the door of the cabinet.
9. Structural shape according to claim 2, characterized in that said flat faces are
positioned on staggered planes.
10. Structural shape according to claim 2, characterized in that said flat faces are
substantially positioned on a same plane.