EP2657390B1

EP2657390B1 - Packing spacer for washing machines with preset collapsible portion

Info

Publication number: EP2657390B1
Application number: EP20130162994
Authority: EP
Inventors: Enrico De Angelis; Carlo Perini
Original assignee: Vic - Viterie Italia Centrale Srl
Current assignee: Vic - Viterie Italia Centrale Srl
Priority date: 2012-04-24
Filing date: 2013-04-09
Publication date: 2014-12-03
Anticipated expiration: 2033-04-09
Also published as: HK1190763A1; EP2657390A1; ITAN20120046A1

Description

The present patent application for industrial invention relates to a spacer used during packing and transport operations of washing machines.
As it is known, washing machines are internally provided with a rotary drum that is designed to be loaded with dirty laundry and is exactly housed inside a basically cylindrical oscillating assembly.
In particular, such a drum is provided on the bottom wall with a shaft that, after crossing the bottom wall of the oscillating assembly that contains it, is connected to an electrical motor in order to be driven into rotation.
Considering that the drum of washing machines rotates with rather high rotational speed (especially during the spin drier cycle), it appears evident that rotation generates high mechanical stress for the oscillating assembly that contains the drum.
In order to prevent said stress from damaging the structure, the oscillating assembly is mounted inside the case of the household appliance with the interposition of suitable elastic connection means that act as shock-absorbers.
Because of the high intensity of the stress, said elastic elements must be adjusted loosely in order to allow the oscillating assembly to be displaced, including significantly, inside the case.
Although it is true that the solution of mounting the oscillating assembly on said elastic elements preserves the structural integrity of the oscillating assembly during the operation of the washing machine, it must be noted that such a solution causes a problem during the packing and transport operations of the household appliance.
In fact, during these operations the oscillating assembly of a washing machine is exposed to remarkable shaking that can cause heavy impacts against the internal walls of the case of the household appliance, resulting in serious damage.
In order to prevent this problem, after completing the assembly of a washing machine, a common practice consists in mounting inside the washing machine some devices designed to stop the oscillations of the oscillating assembly, which are able to neutralize the presence of said shock-absorbers.
Of course, said devices are installed only during the packing and transport operations of the household appliance, and are removed immediately before the household appliance is put in operation, when the oscillating assembly is subject again to the shock-absorbing action of said elastic elements used fixed to the cabinet.
An especially popular type of said devices is represented by a spacer, basically consisting in a cylindrical pin made of rigid plastic material and provided with enlarged head.
A similar spacer is crossed by an axial hole with circular section in which a fixing screw is inserted, having suitable length to protrude shortly from the front end of the hole.
Such a spacer must be inserted horizontally in one of the holes provided on the back wall of the cabinet of a washing machine until the enlarged head is stopped against the external side of the back wall, thus preventing the uncontrolled insertion of the entire spacer inside the household appliance.
Afterwards the tip of the screw inserted in said spacer penetrates inside a hole obtained in corresponding position in the oscillating assembly housed inside the cabinet.
Then the screw of the spacer is screwed until the front end of the spacer energetically interferes against the surface of the oscillating assembly and the enlarged head energetically adheres against the external side of the back wall of the cabinet of the household appliance.
It is easily understood that such a spacer provides a rigid connection between the oscillating assembly and the cabinet of the household appliance.
Moreover, it must be noted that, in order to make such spacers effective, each of them is provided with an insert adapted to be elastically compressed, causing a bulge on the internal wall of the cabinet during the engagement of the screw in the hole on the oscillating assembly to be stopped.
Generally speaking, said elastically deformable insert consists in a rubber collar adapted to be inserted along the screw that crosses the cylindrical rigid body of a spacer.
Such spacers are classified by the experts of the art as "bi-component" because they are formed of two components: a bearing rigid element and an insert made of a material able to expand elastically under compression.
A "bicomponent" spacer of this type is disclosed in patent WO 2006/129176 .
Other models of spacers are known, being characterized in that they have a monolithic structure that comprises a cylindrical stem and an enlarged circular head, both crossed by an axial conduit for insertion of the screw used to fix the spacer between oscillating assembly and the back wall of the cabinet of the washing machine.
A spacer of this second type is disclosed in patent EP 0916760 .
The purpose of the present invention is to realize a new model of spacer characterized by higher shock-absorbing and energy dissipation properties in case of high compression compared to the models of spacers that are currently available on the market.
Said purposes are achieved by the present invention, the main innovative characteristics of which are disclosed in the enclosed independent claims, whereas the depending claims illustrate some preferred embodiments of the invention, forming an integral part of this description.
The new model of spacer of the invention has been realized in order to achieve the aforementioned purposes, being provided with at least one collapsible portion designed in such manner that its elastically deformable components collapse when the spacer is subject to compression beyond a preset threshold value, with consequent dissipation of the impact strength because of collapse and then because of friction between the collapsed parts in mutual rubbing.
For purposes of clarity the description of the invention continues with reference to the enclosed drawings, which are intended for purposes of illustration only and not in a limiting sense, wherein:

Figure 1 is an axonometric view of the packing spacer of the invention;
Fig. 2 is a side view of the spacer of Fig. 1;
Fig. 3 is a sectional view of the spacer of Fig. 1 with a plane passing through the longitudinal axis of the spacer;
Fig. 4 is the same side view of the spacer of the invention as Fig. 2, shown in operating condition, e.g. interposed and tightened between the tub of the washing machine and the back panel of the cabinet of the washing machine.
Fig. 5 is a sectional view of the spacer of Fig. 4 with a plane passing through the longitudinal axis of the spacer;
Figs. 6 and 7 are the same as Figs. 5 and 6, except for they show the collapse of the preset collapsible portion of the spacer in case of compression higher than the preset threshold value after which some elements of the spacer collapse.

With reference to Figs. 1, 2 and 3, according to a first embodiment, the spacer (1) of the invention has a monolithic structure made of molded plastic materials, which comprises a cylindrical stem (20) and a sort of circular pedestal (30) with higher diameter than the cylindrical stem (20).
Said pedestal (30) and cylindrical stem (20) are joined by a cylindrical coupling sleeve (40) with thin walls, with axis (X) orthogonal to axis (Y) of the cylindrical stem (20).
Said pedestal (30), coupling sleeve (40) and stem (20) are all crossed by the same axial conduit (50), the axis of which coincides with the axis (Y) of the stem (20).
More precisely, said coupling sleeve (40) is in intermediate position between a pair of internally excavated identical jaws (60) protruding from the pedestal (30) without adhering neither to the adjacent coupling sleeve (40) nor to the cylindrical stem (20) at least until the spacer (1) is not installed and preloaded.
It must be noted that said cylindrical stem (20) ends with a lower tapered end (21) defined by an opposite pair of inclined planes (22) with direction converging towards the center of the coupling sleeve (40) where said tapered end (21) penetrates shortly.
Said jaws (60) are provided with upper large flat edges (61) sloping according to two converging directions inside the coupling sleeve (40) in intermediate position between them.
It must be noted that the tilt angle of the inclined planes (22) is higher than the tile angle of the sloping edges (61).
Moreover, referring to Fig. 2, it must be noted that said inclined planes (22) do not interfere with the sloping edges (61) at least until the spacer (1) is not installed and preloaded.
Referring now to the structural configuration of said circular pedestal (30), attention is drawn on the fact that the same is formed of a spaced pair of disks (31 a and 31 b) joined by a dense grid of inclined partitions (32) with low thickness, which are adapted to be elastically deformed in order to get the external disk (31 a) closer to the internal disk (31 b).
Now the structure of the cylindrical stem (20) is illustrated, being characterized in that it has an alveolar configuration composed of a dense series of cells or lightening windows (23).
The peculiarity of the stem (20) consists in the provision of a collapsible portion (A) adapted to be elastically deformed when compressed, and also adapted to collapse beyond a preset compression threshold value, thus dissipating the impact strength because of collapse and because of friction between collapsed parts.
More specifically, said portion (A) of the cylindrical stem (20) is provided with a through notch (24) with V-shaped profile that creates a wedge-shaped point (25) in lower position and a corresponding dome (26) in upper position, which continues uninterruptedly into a cavity (26a) that embraces the base (25a) of the point (25).
An opposite pair of teeth (25b) with upward-diverging direction is provided on the two external lateral walls of said wedge-shaped point (25), whereas an opposite pair of teeth (26b) with downward-converting direction is provided on the two internal lateral walls of said wedge-shaped dome (26), said teeth (26b) being situated in such manner to be interfaced against the teeth (25b) without contact, until the spacer (1) is not installed and preloaded as shown in Fig. 3A, which is an enlarged view of a detail of Fig. 3.
Finally, attention is drawn on the fact that said wedge-shaped point (25) is externally provided with bridles (27) for connection to the internal walls of the dome (26).
This description continues with reference to the operation of the spacer (1) of the invention after the same is put into operation.
Referring to Figs. 4 and 5, the spacer (1) is mounted between the tub (L) of the washing machine and the back panel (P) of the cabinet of the washing machine.
First of all, attention is drawn on the fixing screw (VF) of the spacer (1), which is herein shown in maximum screwing position.
In particular, the tip of said fixing screw (VF) is screwed in a hole (F) of the tub (L) of the washing machine, whereas the head (T) of said screw (VF) is engaged in the center of the pedestal (30) against the opening of said axial conduit (50).
It must be said that when tightening the screw (VF) the spacer (1) undergoes a compression preload that determines the following effects:

the lower tapered section (21) of the stem (20) penetrates between the jaws (60) that are diverged due to the interference between inclined planes (22) and sloping edges (61) ;
the coupling sleeve (40) loses its circular profile and assumes a very compressed elliptical profile, as shown in Fig. 5;
the teeth (26b) of the dome (26) are pressed against the teeth (25b) of the point (25), as shown in the enlarged view of Fig. 5A.

It must be noted that said diverging movement of the jaws (60) prevents the spacer (1) from coming out backwards from the hole (FO) provided on the panel (P).
When the spacer (1) is subject to stress, the pedestal (30) elastically collapses because of the deformation of its grid of inclined partitions (32).
Otherwise said, the pedestal (30) also acts as shock-absorber to limit the damage that may be suffered by the structure of the household appliance in case of a violent impact (such as in case of fall from some height) received during storage or transport operations until the oscillating assembly is rigidly connected with the cabinet by means of multiple specimens of the spacer of the invention.
In such a case, the violent shaking suffered by the oscillating assembly of a washing machine could generate an energetic tractive force towards the inside of the household appliance against the screws (VF) of the various spacers screwed onto the body of the tub (V) of the washing machine.
In this case, the head (T) of the screw (VF) will compress the pedestal (30), causing the elastic deformation of the grid of inclined partitions (32).
If the spacer (1) is compressed beyond a preset value - as shown in Figs. 6 and 7 where arrows (FR) are used to indicate the compression forces - the teeth (25b) of the point (25) collapse, being compressed by the teeth (26b) of the dome (26), thus favoring a short axial travel of the dome (26) towards the point (25), as shown in the enlarged views of Figs. 6A and 7A.
However, said travel is hindered by the friction developed between the rubbing surfaces, e.g. the internal surface of the wedge-shaped dome (26) on one side, and the external surface of the wedge-shaped point (25) on the other side, as shown in the enlarged views of Figs. 6A and 7A.
During collapse the bridles (27) prevent the bulging of the stem (20) in correspondence of he preset collapsible portion (A).
In the attached figures numeral (1a) indicates a pair of wings provided on the pedestal (30) to favor grabbing and handling of the spacer (1) of the invention.

Claims

A packing spacer for washing machines, comprising a tubular cylindrical stem (20) and a pedestal (30), both crossed by an axial conduit (50) for a fixing screw (VF) of the spacer,
characterized in that
said tubular cylindrical stem (20) is provided with a collapsible portion (A) provided with interfaced means (25b and 26b) adapted to be elastically deformed when compressed, and also adapted to break if the compression exceeds a preset threshold value.
A spacer as claimed in the preceding claim, characterized in that, in said collapsible portion (A), the stem (20) is provided with a V-shaped through notch (24) that forms a lower wedge-shaped point (25) and a upper dome (26), said upper dome (26) having internal lateral walls provided with an opposite pair of teeth (26b) converging downwards and situated in such manner to be interfaced against corresponding teeth (25b) provided on an external lateral wall of said lower wedge-shaped point (25), diverging upwards.
A spacer as claimed in the preceding claim, characterized in that said teeth (25b) of the lower wedge-shaped point (25) are dimensioned in such manner to break under the compression action of the teeth (26b) of the upper dome (26), when the spacer (1) is subjected to compression exceeding the preset threshold value.
A spacer as claimed in the preceding claim, characterized in that said lower wedge-shaped point (25) is externally provided with bridles (27) for connection to the internal walls of the upper dome (26).
A spacer as claimed in one of the preceding claims, characterized in that said pedestal (30) and said tubular cylindrical stem (20) are joined by a cylindrical coupling sleeve (40) provided with thin walls, wherein said cylindrical coupling sleeve (40) has an axis (X) orthogonal to the axis (Y) of the tubular cylindrical stem (20); said cylindrical coupling sleeve (40) being crossed by said axial conduit (50).
A spacer as claimed in the preceding claim, characterized in that said cylindrical coupling sleeve (40) is in intermediate position between a pair of internally excavated jaws (60) protruding from the pedestal (30) without adhering neither to the cylindrical coupling sleeve (40) nor to the tubular cylindrical stem (20), until the spacer (1) is not installed and preloaded.
A spacer as claimed in the preceding claim, characterized in that said tubular cylindrical stem (20) ends with a lower tapered section (21) defined by an opposite pair of inclined planes (22) converging towards the center of the cylindrical coupling sleeve (40), wherein said tapered section (21) penetrates inside said cylindrical coupling sleeve (40).
A spacer as claimed in one of the preceding claims, characterized in that said tubular cylindrical stem (20) has a cell-like configuration having a series of cells or lightening windows (23).
A spacer as claimed in one of the preceding claims, characterized in that the spacer has a monolithic structure obtained from molding plastic materials.