GB2410059A

GB2410059A - Hinge for electrical appliance with ramp-shaped block exerting increasing torque upon opening of door

Info

Publication number: GB2410059A
Application number: GB0425024A
Authority: GB
Inventors: Silvano Fumagalli
Original assignee: Candy SpA
Current assignee: Candy SpA
Priority date: 2003-11-18
Filing date: 2004-11-12
Publication date: 2005-07-20
Anticipated expiration: 2024-11-12
Also published as: GB2410059B; GB0425024D0; ITMI20030533U1

Abstract

A domestic electrical appliance (1) such as a refrigerator or electric oven with a door (3) which is laterally hinged between a lower supporting hinge and an upper hinge. The upper hinge comprises an angled bracket (9) with a projecting portion and the upper edge of the door is provided with a ramp-shaped slide block (18) which progressively interferes with the projecting portion when the door is opened to angles greater than a predetermined value exerting an increasing resistant torque as the angle of opening increases. The bracket 9 may comprise a short arm 19 which also comprises a ramp. When the door 3 is opened beyond a specific angle, for example 130-140 degrees, the ramp block 18 begins to interfere with arm 19 of the projecting portion exerting a resistant torque that is greater the greater the contact pressure exerted between block 18 and arm 19. The hinge may be used in refrigerators or microwave ovens.

Description

DOMESTIC ELECTRICAL APPLIANCE

This invention relates to domestic electrical appliances in general and in particular a refrigerator having at least one door, preferably but not necessarily of the "top door" type, supported by a retracting hinge which when opened close to or corresponding to a predetermined maximum exerts a resistant torque which prevents or at least restrains further opening of the door.

Advantageously the invention may be combined with known devices, such as vertical displacement of the hinge supports, to encourage complete closure or automatic opening of the door.

Domestic refrigerators in which the door is supported by a hinge provided with relatively complex cam devices which ensure complete closure of the door and possibly a stable opening position are known, for example from document US 2003/01 51339A1 and the prior art cited therein.

Additional restraining means which define the maximum amount to which the door can open are also known.

In addition to structural complexity and consequent cost, these arrangements have a number of technical disadvantages.

They are also unsatisfactory from the ergonomic point of view.

The cam devices in the known art essentially comprise two toothed bushes which are axially juxtaposed along the hinge axis, with the teeth engaging each other ensuring a predetermined relative angular position between the two bushes, and possibly two or more relative angular positions.

The two bushes are linked in rotation to the body and door of the refrigerator respectively.

Mutual engagement between the teeth of the bushes is ensured by the weight of the door, through gravity.

An adequate torque exerted on the door by the user results in a vertical component lifting the door with a constant force, equal to and opposing its weight, through the effect of interaction between the appropriately inclined flanks of the teeth, disengaging the teeth and permitting the door to rotate in order to open or close.

Clearly the supporting hinges must be constructed so as to permit this axial displacement of the entire door.

When the teeth are disengaged the resistant torque is virtually zero.

There is therefore the disadvantage for the user that during the initial stage of opening the door a relatively high opening moment has to be exerted, imparting some angular velocity to the door, as a result of which, and the inertia of the door which is no longer restrained, the door tends to escape the user's control and open beyond any limit, with possible breakage or warping of the stop devices, if present, or an undesired impact between the door and any obstacle.

The same disadvantage occurs when closing the door in a situation where the cam devices establish a predetermined open position.

The object of this invention is therefore to overcome these disadvantages and provide a refrigerator with a door supported by an extremely simple hinge structure which allows normal effortless opening and exerts a resistant torque with a progressive restraining action at opening angles close to a predetermined value.

This object is accomplished by the refrigerator according to the invention, which is characterized in that the refrigerator door is hinged with two supporting brackets, an upper and a lower respectively, which are incorporated in the refrigerator, and the said door is provided with an inclined slide block which progressively interferes with the upper supporting bracket at opening angles of the said door exceeding a predetermined value.

The interference brings about elastic deformation of the support and/or elastic deformation of the slide plate and develops a resistant torque which is substantially proportional to the amount of deformation.

Therefore, unlike known gravity systems, which develop a constant resistant torque, or no torque, in this invention a progressive action which is more effective for limiting opening of the door, even from the ergonomic point of view, is obtained.

In fact the progressive resistant torque provides the user with timely feedback of the approach of maximum opening conditions which must not be exceeded.

The invention will now be more particularly described with reference to a practical embodiment provided solely as an indication and without restriction with reference to the appended drawings in which: - Figure 1 is a partial perspective view of a preferred embodiment of the refrigerator according to this invention, - Figure 2 is a view from above of the upper hinge unit of a door of the refrigerator in Figure 1, with the door closed, - Figure 3 is a cross-section of the hinge unit in Figure 2 along the line A-A in Figure 2, - Figure 4 is a cross-section of the supporting bracket for the hinge unit in Figure 2 along the line B-B in Figure 2, - Figure 5 is a cross-section of a portion of the door along the line C-C in Figure 2, - Figure 6 is a view from above of the upper hinge unit in Figure 2 with the refrigerator door in its maximum open position, - Figure 7 is a cross-section of the upper hinge unit along the line D-D in Figure 6 with the refrigerator door in the maximum open position.

As shown in Figure 1, in a preferred embodiment according to this invention the refrigerator comprises a cabinet 1, having two internal spaces, one of which, 2, is visible.

The body of the refrigerator is closed at the front by two opening doors 3, 4 hinged vertically on one side. Top door 3 is shown in the open position and bottom door 4 in the closed position.

In refrigerators with a top door such as that shown, upper edge 5 of top door 3 is substantially flush with upper wall 6 of the cabinet and hides an accessible control panel 7 on the upper edge of the cabinet.

A sealing bead 8, which is in itself conventional, attached to the inside surface of the door and preferably of the magnetic type, ensures a leaktight seal for the access aperture.

Door 3 is hinged to the cabinet by means of an upper hinge unit and a lower hinge unit.

The upper hinge unit generally comprises a right angled bracket 9 attached to the front upper edge of cabinet 1 with screws so that it projects.

The projecting portion of right angled member 9 overlaps upper edge 5 of the door and is provided with a vertical pin 10 which is inserted into a cylindrical seat formed in the upper edge 5 of door 3.

The structure of the lower hinge unit is wholly similar and comprises a right-angled bracket 11 secured to the front structure of the cabinet with a projecting portion on which lower edge 12 of door 3 is supported (appropriately through the intermediary of a supporting bearing).

Bracket 11 is also provided with a vertical pin, which is not visible, which is inserted into a cylindrical seat formed in the lower edge of the door.

The bracket is sufficiently rigid to support the weight of the door.

The two bars 9, 11 and corresponding pins like 10 form end hinges on which the door hinges.

Advantageously door 3 is provided with recesses on the upper and lower edges (recess 13 on upper edge 5 can be seen in Figure 1) to house the projecting parts of bars 9, 10 along the edges so that when the door is closed the two bars are virtually invisible.

Advantageously the pins of the two hinges, such as 10, are not perfectly vertically aligned, but define a hinge axis with some inclination in the vertical plane perpendicular to the front of the refrigerator.

Specifically pin 10 of the upper hinge is slightly more set back (towards the rear of the cabinet) than the corresponding pin of the lower hinge.

In this way, when door 3 has not been opened by more than 90 , it tends to close automatically, through gravity, even in the absence of any external thrust.

When opened through more than 90 door 3 tends to open further, for the same reason, even in the absence of an external thrust.

Figures 2 and 3 show the upper hinge unit in greater detail, in a view from above and in cross-section respectively.

Right-angled bracket 9 has a vertical member 1 secured by screws, such as 14, to the front upper edge 15 of the cabinet.

The heads of the screws are protected by a suitable moulding 15 which is attached to the inside profile of door 3.

The projecting portion preferably but not necessarily extends as a flat lateral end 16, in the form of a washer, with a central opening in which the pin of hinge 10, which is inserted in the cylindrical seat 17 formed in the door, is secured by force or screwing.

On the upper surface of door 3, externally from head 16 and in a convenient angular position with respect to the axis of the hinge, there is a ramp-like block 18 whose height increases clockwise in relation to the plane of the upper surface of the door.

Conveniently, as shown in cross-section in Figure 5, block 18 may comprise a block of plastics material which is resistant to wear, such as nylon, removably housed in a suitable seat in door 3.

Conveniently, as illustrated in the cross-section in Figure 4, head 16 is also connected to projecting portion of bracket 9 by a short arm 19 which has on the underside a matching ramp 20 with a recess which deepens clockwise in relation to the upper plane of the door.

The ramp may be obtained by pressing or by the removal of material.

Unlike the hinge structures in the known art already mentioned, which must allow some axial play between the door and the hinges (to allow the toothed pair to disengage), the hinges according to this invention preferably enclose the door with minimum axial play.

Consequently, as shown in Figure 6, when door 3 is opened beyond a specific angle, for example 130 - 140 , ramp block 18 begins to interfere with arm 19 of the projecting support exerting a resistant torque which is greater the greater the contact pressure exerted between block 18 and arm 19.

As will be seen immediately from Figure 7, this in turn is substantially proportional to the deformation imposed by interference on projecting support 9, which tends to bend in the direction of arrow F. and/or compression deformation developed on block 18.

It is clear that to some extent the two phenomena will coexist, depending upon the elasticity of the support and that of a block.

Matching ramp 20 on arm 19, with a gradient substantially equal to that of the block, ensures a relatively uniform distribution of the contact pressure, reduces friction wear and avoids permanent local deformation of the stressed parts (in particular the block).

The arrangements described above also find application where appropriate in restraining opening of the lower door of the refrigerator, and more generally in restraining the opening of any door in any domestic electrical appliance which is hinged on one side in which incorrect operation of the door may cause damage to it or surrounding objects.

A specific example of domestic electrical equipment other than refrigerators in which the invention may be usefully used comprises microwave ovens.

The above description relates to a preferred embodiment of the invention, but it is clear that many variants may be made to it.

In particular, head 16 which extends laterally is used only to make it possible to manufacture a door structure in which the front part of the door wholly masks the upper hinge (and lower hinge) when the door is closed, purely for aesthetic reasons.

Likewise block 18, which is presented as a component which is separate from the door body, may simply comprise a convenient prominence in the upper profile of the door which under specific opening conditions interferes gradually with the projecting support.

In this respect, referring again to Figure 1, it will be seen that in addition to recess 12 door 3 has a similar recess 21 at the opposite end of the upper edge to permit hinged attachment of the door on one side or the other in a known way.

Figure 1 clearly shows that this recess 21 (like the equivalent recess 12 at the other extremity) is only partly closed along the edge between the upper edge adjacent to the door and the upper edge of the door, which itself forms an interference ramp 22.

Claims

CLAI MS

1. Cabinet-type domestic electric appliance (1) having a door (3) laterally hinged between a lower hinge and an upper hinge, the upper hinge comprising a right-angled or other bracket (9) secured to the cabinet and having a projecting portion terminating in a head with an eye (16) for a pin (10) of a hinge attached to the said door (3) characterized in that the upper edge (5) of the said door has a ramp-shaped block (18, 22) which progressively interferes with the said projecting portion over a predetermined range of angles of opening of the said door exerting an increasing resistant torque as the door opens.

2. Domestic electrical appliance according to Claim 1, in which the said projecting portion is housed in a recess (12) in the upper edge (5) of the said door (3) and the said head (16) incorporating an eye extends laterally from the said projecting portion towards the side of the said appliance.

3. Domestic electrical appliance according to Claim 2, in which the said head (16) bearing an eye is connected to the said projecting portion by an arm (19) provided with an entry ramp (20) for the said ramp-shaped block (18, 22).

4. Domestic electrical appliance according to any of the preceding claims in which the said ramp-shaped block (18) is a resilient member removably housed in a seat formed in the upper edge of the said door (3).

5. Domestic electrical appliance according to any of the preceding claims in which the said predetermined range of angles of opening lies between 130 and 180 .

6. Domestic electrical appliance according to any of the preceding claims, in which the said domestic electrical appliance is a refrigerator and the upper edge (5) of the said door (3) is substantially flush with the upper wall (6) of the said refrigerator.

7. A domestic appliance substantially as herein described with reference to the accompanying drawings.