EP0546379B1

EP0546379B1 - Device for fixing the floating unit to the cabinet of a washing machine, washing-drying machine or the like

Info

Publication number: EP0546379B1
Application number: EP92120061A
Authority: EP
Inventors: Cesare c/o Whirlpool Italy s.r.l. Gorini
Original assignee: Whirlpool Europe BV
Current assignee: Whirlpool Europe BV
Priority date: 1991-12-09
Filing date: 1992-11-25
Publication date: 1997-09-17
Anticipated expiration: 2012-11-25
Also published as: ITMI911067V0; DE69222271D1; IT222078Z2; EP0546379A1; ITMI911067U1

Description

This invention relates to a device for fixing the floating unit, ie the tub-drum unit, to the cabinet of a washing machine, washing-drying machine or the like, said cabinet resting on a floor or the like via usual support feet, said device comprising a plurality of suspension members each comprising a damper element and an elastic or spring element.
With particular reference to washing machines, a high level of vibration and noise is generated during their operation, in particular during spinning. This vibration and/or noise is due mainly to the transmission of forces generated by the floating unit during washing machine operation to the machine cabinet. Said forces are transmitted via suspension members associated with the floating unit of the washing machine and connecting this unit to the machine cabinet.
In this respect, it is known to connect the top of said unit to the machine cabinet by two or four springs, the bottom being connected to the cabinet by dampers.
In this manner the forces generated by the floating unit during machine operation (and in particular during each spinning stage) are transmitted to the cabinet sides and hence to its top and bottom and to the feet. This results in a high level of cabinet vibration and hence considerable noise during the use of the washing machine.
Washing machines or the like are known in which the floating unit is supported by suspension members comprising elastic elements (or springs) and damper elements.
These members, acting as "carrying legs" for the floating unit, rest on the base of the cabinet. During washing machine operation the legs can move in every plane of the space containing their axis, and are connected at their free end to the cabinet rather than directly to the feet of this latter.
BE-A-650 246 discloses a device for fixing the tub-drum unit in which each suspension member is connected to a corresponding support foot so as to transfer directly to the floor the stresses generated by the tub-drum unit. The support feet are made of rubber, which may create problems of cracking/tearing and assembling.
An object of the present invention is to provide a washing machine of the stated type with its floating unit supported by suspension members of the aforesaid type in which vibration is reduced and the noise generated during machine operation is limited.
A particular object of the invention is to provide a machine of the stated type in which the forces exerted by the floating unit on the washing machine cabinet during machine operation are minimal.
A further object is to provide a washing machine or the like which is light, easily transported, and in which the cabinet performs a purely decorative function, allowing its structural characteristics to be reduced.
A further object is to provide a machine of the stated type which is easier to assemble than known machines, can be more easily factory-tested than these latter, and is simpler to maintain that known machines.
These and further objects which will be apparent to the expert of the art are attained by a machine of the aforesaid type, having the features reported in the appended main claim.
The present invention will be more apparent from the accompanying drawing, which is provided by way of non-limiting example and in which:

Figure 1 is an enlarged longitudinal section through the device according to the invention;
Figure 2 is a partial schematic view of a washing machine floating unit supported by the device of the invention;
Figure 3 is a modification of the device of Figure 1; and
Figure 4 is a further modification of the device according to the invention.

With reference to Figures 1 and 2, the floating unit 1 of a washing machine comprises a tub 2 containing a drum (not visible in the figures) in any known manner. This latter is rotated within the tub via a pulley 4 by a usual electric motor 5 the operation of which is controlled by a usual timer (not shown). The motor 5 rotates a rotating member 7 (such as a drive pulley) which is connected to the pulley 4 by a usual belt 8.
The floating unit is supported by known suspension members 10 comprising an elastic element associated with a damper element (these not being shown separately). At least one of said members 10 (in fact all the members in the examples shown in the figures) is associated with a support foot 12 for the washing machine to which the unit 1 pertains.
The tub 2 comprises lateral flanges 15 with which there are associated support elements 16 having a broken-line cross-section and comprising a flat body 17 from the ends of which there extend two parts 18, 19 perpendicular to said body and extending in opposite directions.
Each support element 16 is fixed to two suspension members 10, one at each end.
Each member 10 comprises a sleeve 20 within which there moves a piston 21 comprising a rod 22, on the threaded free end 23 of which there is screwed a usual nut 24.
The end 23 penetrates through a corresponding hole 25 in the relative support element 16.
The nut 24 cooperates with a metal washer or ring 27 acting on a first elastically deformable annular member 28, for example a rubber or similar member, resting on the body 17 of the element 16.
Said rod 22 has a collar 29 acting on a metal ring or washer 30 which cooperates with a second elastically deformable annular member 31, for example of rubber or the like, resting on said body. Said second member 31 lies below the first member 28.
The sleeve 20 terminates at the base 33 of the cabinet (not shown) of the washing machine to which the unit 1 pertains.
At said base 33 the sleeve comprises a collar 36 acting on two superposed elastically deformable members 37, 38 (for example of rubber or the like) of substantially cylindrical shape with respective axial cavities 37A and 38A.
The members 37 and 38 rest directly on the base 33 of the washing machine cabinet.
Said base comprises, coaxial with the cavities 37A, 38A of said members 37, 38, a through hole terminating at the face 41 of said base where the foot 12 is arranged.
The hole 40 comprises a substantially frusto-conical portion 43 opening at that face 44 of said base 33 opposite the face 41, and a cylindrical intermediate portion 45 opening into a hemispherical portion 46. This latter partly houses a ball 47 associated with the sleeve 20 via a pin 48 inserted through the cavities 37A and 38A of the members 37 and 38 and through said hole 40. The pin 48 is threaded at 50 at that end which cooperates with said ball 47. This latter is partly inserted into a hemispherical seat 51 in the foot 12 in front of the said portion 46 of the hole 40.
Finally the foot 12 comprises a lower part 55 of any non-slip material and is fixed to the base 33 of the washing machine cabinet by usual screws 58.
During the use of the washing machine the unit 1 is subjected to movement and generates forces which are transferred via the flanges 15 to the damper members 20 and from these directly to the corresponding feet 12. These forces are then discharged directly onto the floor 60 (or the like) on which the washing machine rests without them being converted into stresses generated by said unit 1 on the machine cabinet, and in particular on its base 33. This means that the cabinet can be designed very freely, without consideration for structural and mechanical requirements deriving from the need to support stresses generated on it by the floating unit 1, this consideration being however required in the case of washing machines or the like of the state of the art.
In a washing machine provided with the device of the invention, the substantially oscillating movement of the unit 1 (and the forces deriving from it) is initially damped by the deformable members 28 and 31. This movement gives rise to movements of each member 20 in planes containing its longitudinal axis K.
These movements are partly damped by the deformable members 37 and 38 to such an extent that only a minimum part of the forces deriving from them (a totally negligible part) is transferred to the base 33.
Each suspension member 20 absorbs and damps in known manner the stresses and movements of the unit 1.
As stated, each member also moves within at least one plane containing its axis K. This movement causes the pin 50 rigid with the sleeve 20 to move within the cavities 37A, 38A and the hole 40. The movement of the member 10 therefore results in movement of the ball 47 rigid with said pin 50. The ball 47 on the one hand allows non-rigid coupling between the member 10 and the relative foot, and on the other hand contributes to damping the forces transmitted by said member to the foot 12. To improve this damping, the foot 12 can be constructed of any known deformable material (such as rubber).
In Figures 1 and 2, connection between each member 10 and the relative foot 12 is direct. In a modified embodiment (shown in Figure 3 in which parts corresponding to those already described are indicated by the same reference numerals), this connection is indirect and is obtained via a bar 70 connected to the ball 47 by a threaded pin 71 and hinged at 72 to the sleeve 20 of the corresponding member 10. The hinge 72 can be in the form of an elastic joint or a ball joint 75 to which opposite ends 76 and 77 of respectively the bar 70 and the sleeve 20 are connected. The bar also comprises a collar 79 acting on the members 37 and 38. Again in this modified embodiment of the invention the forces are transmitted from the floating unit 1 to the floor 60 via the foot 12, the machine cabinet not being subjected to particular stressing as occurs with known washing machines.
A further embodiment of the device of the invention is shown in Figure 4 in which parts corresponding to those of the already described figures are indicated by the same reference numerals. In this embodiment, the sleeve 20, the pin 48 and the ball 47 are joined together in any known manner (for example by welding) or are constructed in one piece by casting or pressing.
The ball is forcibly inserted into the seat 51 of the foot 12, which snap-fits to the wall 123 of a hole 124 provided in the base 33 of the washing machine cabinet. The foot 12 comprises a substantially frusto-conical upper part 125 slotted (at 126) in at least two opposing positions. The slots 126 hence define two portions 125A and 125B of the part 125 which are elastically movable relative to each other.
The part 125 is separated from a first cylindrical part 128, arranged to cooperate with the face 41 of said base 33, by an annular recess 127. This latter is arranged to cooperate directly with the wall 123 of the hole 124; in this manner said parts 125 and 128, having their maximum diameter greater than that of the hole 124, act on the opposing faces 41 and 44 of the base 33 to snap-lock the foot (which is fitted to the washing machine cabinet by insertion into the hole 124 from the face 41 side).
The foot 12 also comprises a second surface-threaded cylindrical part 130 arranged to cooperate with an annular threaded member 131 carrying the lower part 55 of the foot 12. Cooperation between said part 130 and the member 131 enables the height of the foot 12 to be adjusted.
Finally, the hole 40 has a diameter which is constant but is considerably greater than the diameter of the pin 48. The hole is formed in a single deformable element 200.
The use of the device of Figure 4 is analogous to that described with regard to the preceding figures and will therefore not be repeated.
A device of the described type therefore makes the cabinet of a washing machine or the like independent of mechanical or design requirements based on the stresses generated by the floating unit during the machine operation.
The device is of relatively simple construction and is reliable in use.
Two embodiments of the invention have been described. Further embodiments are however possible, and are to be considered as falling within the scope of the present document.

Claims

A device for fixing the floating unit (1), i.e. the tub-drum unit, to the cabinet (33) of a washing or a washing-drying machine, said cabinet resting on a floor (60) via support feet (12), said device comprising a plurality of suspension members (10) each comprising a damper element and an elastic or spring element, each suspension member (10) being connected to a corresponding support foot (12) arranged on the cabinet base (33) so as to transfer directly to the floor (60) the stresses generated in said members (10) by the floating unit (1) during washing machine operation, characterised in that a connection member (47) in the form of a spherical element associated with the suspension member is provided between said foot (12) and the suspension member (10), the connection member (47) being arranged in a seat provided in the foot (12) said seat enabling the suspension member (10) to undergo movements relative to the foot (12) along any plane containing its axis (K).
A device as claimed in claim 1, characterised in that the connection member is arranged in two opposing seats (46, 51) provided in the foot (12) and on a face (41) of the cabinet base (33) where the foot (12) is arranged respectively.
A device as claimed in claim 1, wherein each suspension member (10) comprises a damper element and an elastic element and incorporates a sleeve (20) within which a piston (21) moves, characterised in that said piston comprises a rod (22) associated with a lateral support element (15) fixed to the floating unit 1, the connection between said rod and the corresponding lateral element (15) being made via at least one elastically deformable element (28, 31).
A device as claimed in claim 3, characterised in that the rod (22) comprises a threaded end (23) inserted through a hole (25) in the corresponding support element (15) and cooperating with a nut (24) acting, via an annular element, on an annular cylindrical member (28) defining said said deformable element resting on the support element (15).
A device as claimed in claim 3, characterised in that the rod (22) comprises a collar (29) cooperating via an annular element with an annular cylindrical member (31) defining the deformable element and in contact with the support element (15).
A device as claimed in claims 2 and 3, characterised in that the sleeve (20) of each suspension member (10) comprises at its free end a collar (36) cooperating with at least one elastically deformable damper member (37, 38) of annular shape positioned between said sleeve and the base (33) of the washing machine or the like, to said sleeve (20) there being connected a pin (48) fixed to the spherical element (47) associated with the support foot (12).
A device as claimed in claim 6, characterised in that the pin (48) associated with the sleeve (20) penetrates through a hole (40) in the washing machine base (33) having two portions (43, 46) of different shape, one of these portions (43) being frusto-conical and widening into that face (44) of said base (33) facing said sleeve (20), the other portion (46) being of hemispherical shape to house part of the connection member (47) and opening into that face (41) of said base (33) with which the support foot (12) is associated.
A device as claimed in claim 1, characterised in that the foot (12) is constructed of elastically deformable material, preferably rubber.
A device as claimed in claims 1 and 3, characterised in that the suspension member (10) is connected to the connection member (47) via a bar (70) associated with the sleeve (20) of said member (10), this latter being able to undergo at least small movements in planes containing its axis (K) relative to the bar (70).
A device as claimed in claim 9, characterised by comprising an elastic joint joining together the bar (70) and the sleeve (20) of the suspension member (10).
A device as claimed in claim 9, characterised by comprising at least one elastically deformable annular damper member (37, 38) between the bar (70) and the washing machine base (33), said bar (70) being provided with a pin (71) connected to the connection member (47) which is contained in the annular damper member (37, 38) and in the hole (40) in said base (33).
A device as claimed in claims 1 and 3, characterised in that the sleeve (20) of the suspension member (10) is formed in one piece with the connection member (47).
A device as claimed in claims 1 and 3, characterised in that the sleeve (20) of the suspension member (10) is connected to a pin (48) associated in any known manner with the connection member (47).
A device as claimed in claim 1, characterised in that the foot (12) is associated with the washing machine cabinet by snap-fitting.