Cabinet Pressing

RELATED APPLICATIONS

This application claims priority from Mexican application Serial No. MX/a/2010/003431 filed Mar. 26, 2010, which is incorporated herein by reference in its entirety.

FIELD OF INVENTION

The present invention lies in the field of household appliances and more specifically to household appliances which by means of pressing or inlay in at least one of their panels increases their natural frequency to decrease vibrations and noise of the household appliance.

BACKGROUND

The structure of household appliances is generally manufactured of a laminate metal or a laminate plastic, which has faces which cover the contour of the household appliance. These faces form membranes or panels. The resonance of these membranes can cause the household appliance to “walk” and create undesired noise to the operator. It is because of this that the structure is reinforced to avoid the natural frequencies of the same, lie in the same operation range as the machine, that is, within the range of operational frequencies. A response pattern to a panel's vibration can have several spikes, each spike representing a natural frequency or panel resonant. The first natural frequency is the panel's lowest natural frequency. Operating the household appliance at a frequency close to the panel's natural frequency can result in a response of high vibration resonant of the panel, which causes the household appliance to “walk”.

A household appliance without inlays on the panels is known in the field as leaning to have natural frequencies within the ranges of operation frequencies. Given this, the great majority of household appliances will modify their panels adding inlays, thus increasing the natural frequency of the household appliance. In the past, cabinets have been used whose panels have a higher natural frequency than the frequency of operation. Several household appliances which modify their cabinets to un-equalize the natural frequencies compared to the frequencies of operation are described as follows.

German patent DE 8226335 makes known casings for household appliances, such as washers, dryers, dishwashers, specifically the lateral walls are provided with reinforcement grooves.

Model Auge 90 manufactured by general Electric Mexico during the 1990s decade included inlays and pressings in its time, which, upon measuring the vibration spectrums of said model, it is found that the first natural frequency of that casing was between 18.8 and 29.38 Hz, whereas its centrifuge operation velocity is 9.4 Hz. That is, the natural frequency of the casing is at least double the velocity of operation. The high natural frequency is due to the lateral pressings or inlays, as well as to the thickness of the laminate, this being 1.02 mm (0.040 inches).

British patent No. 2 288 505 makes known that the casing's lateral walls are high as compared to their widths and that they are provided with plane wedges, parallel between them, mainly vertically oriented, where the lateral walls additionally comprise three close fitting wedges in comparison to their length spread over the surface of the lateral wall, of the same width, at an unequal distance from each other.

Korean patent no. 20030064048 makes known a casing for a washer which comprises a body which has a drum set to rotate in a horizontal manner, a motor, a service access on its back part, a base installed on the body of the cabinet to form the washing machine's exterior, a front cover and an upper cover. Several folded parts are formed surrounding the service access to prevent the vibrations of the motor and the drum from being transmitted to the cabinet and a plurality of grooved parts are formed on both sides of the cabinet. The washer is operated in a stable manner to reduce vibrations and noise.

Mexican Patent Application number PA/a/2000/003593, same as U.S. Pat. No. 6,512,831 makes known an appliance to reduce noise emitted by an article which has a cabinet which supports at least one component which emits at least one acoustic pressure wave. In a preferred form, the appliance comprises at least one diffuser which has at least one deflection surface. The diffuser is coupled to the cabinet and placed in relation to the component, in such a way that the acoustic pressure wave emitted in the component is deviated by the deflection surface in a predetermined direction. The diffuser can be used to deviate the acoustic pressure waves in a way such that they may collide between them. The appliance can additionally include at least one absorbent. The diffuser is strategically placed to deviate acoustic pressure waves emitted by the component to the absorbent, to reduce the noise emitted by the appliance.

U.S. design No. 236,152 makes known a dryer with a couple of longitudinal grooves on the lateral walls.

U.S. design No. 465,308 makes known a dryer with three cross grooves on the lateral walls.

U.S. Pat. No. 5,504,281 makes known an acoustic attenuator which comprises a porous material comprised of sintered materials and/or joined at their contact points, which have at least one portion of the pores continually connected, where said porous material has an interstitial porosity varying between 20 and 60 percent, an average pore diameter varying between 5 and approximately 280 micrometers, a convolution factor of approximately 1.25 to 2.5, a density varying approximately between 5 and 60 pounds per cubic foot and a module of approximately 12,000 pounds per square inch or higher, where the porous material has at least one hole and where said interstitial porosity values, pore diameter, convolution factor, density and module are for the porous material in absence of any of the cross holes, and where said average cross hole diameter is higher than the average pore diameter.

U.S. Pat. No. 5,855,353 makes known a method and appliance to cushion vibration such as sound in a device which generates vibrations, such as an appliance. A limited layer and an adhesive layer are provided. The adhesive layer includes material which improves the viscosity, such as cellulose fibers and adhesive material. The limited layer is adhered to the surface of said device with the adhesive layer.

U.S. Pat. No. 6,460,949 makes known a cabinet for a washer which includes a vibration plaque for testing placed on the front panel to reduce vibrations. A groove is provided on the lower part of the vibration plaque for testing and a groove is formed in the lower part of the front panel which corresponds to the groove on the plaque. A plurality of screw holes are provided to the upper and lower extremes of both the vibration plaque for testing and the front panel, and the vibration plaque for testing is joined to the front panel. The vibration plaque for testing has a plurality of hooks which are provided on both sides of the inner surface and the front panel has a plurality of holes which are hooked unto the hooks provided on both sides of the same so that the vibration plaque for testing will be more firmly set unto the front panel. The whole vibration plaque for testing is convex towards the outside and at least one member which absorbs vibrations is joined to the inner surface of the vibration plaque for testing, thus contacting the front panel.

U.S. Pat. No. 6,931,367 makes known a method to design deformations which aid in optimal noise reduction related to vibration in an escape component. The method consists in defining an initial form for the escape system component based on the available space and the characteristics of the escape flow. The form is converted to a grid which has a plurality of interconnected grids. The grid is deformed to define an optimal theoretical configuration for the escape system component which will eliminate at least the natural frequencies selected. The resulting form is later converted to a plurality of small plane surfaces which intersect and a cloud point is created from the arrangement of small plane intersecting surfaces of the optimal theoretical component escape system. The cloud point is used to regulate the intersecting surfaces and to achieve a configuration which is optimally manufacturable for the component escape system.

U.S. Pat. No. 7,062,051 makes known a method for improving the distribution of frequency of modal resonance of an acoustic panel device with a bent wave in resonant distribution form which involves the analyzing of distribution of the modal resonant frequencies of the panel, identifying a modal resonant frequency which is spaced in a non-uniform manner relative to adjacent modal resonant frequencies, identifying a location on said panel which exhibits anti-nodal behavior in said modal resonant frequency and changing the nearest position to double the wave vibration in said location.

US publication number 2005/0257326 makes known a lateral panel for an appliance meant for the care of textiles. The lateral panel includes a pressed pattern to increase the first natural frequency (or first harmony) of said lateral panel. Preferably, the first natural frequency is substantially greater than the ordinary operation frequency or frequency of push of the appliance. For example, in a washing machine, the first natural frequency of the lateral panel is 1.6 times higher than the drum's maximum rotational frequency of the washing machine.

In none of the previous known art backgrounds found, is it made known that the panels contain pressings or inlays which have polygonal figures, where the rhomboidal and rhombus figures are preferred. Additionally, none of the previous art found makes known that the panels have pressings or inlays which have triangular figures. In similar manner, none of the previous art found makes known that any panels have a hexahedron form. None of the previous art found makes known that the panels have pressings or inlays which have combined polygonal figures, where the rhomboidal and rhombus figures are preferred with triangular forms. Similarly, none of the previous art makes known panels which have pressing or inlays which combine hexahedron forms and triangular figures.

BRIEF DESCRIPTION OF THE INVENTION

As was previously mentioned, the faces, panels or membranes of the household appliance create resonance during the operation of the household appliance. Resonance is the tendency of the system to oscillate in large amplitudes in some frequencies. These frequencies are known as resonance frequencies. In these frequencies, even small push forces can cause oscillations with large amplitudes. So that, the resonance of these membranes can create vibrations of the household appliance and create undesired noise for the operator, since the sound is a factor associated with noise and consequently, with vibration. Given the previous, the cabinet's panels or walls act as a membrane and its natural frequencies are low, so that the inlays aid to raise these frequencies stopping the propagation of the wave in light of the change of direction. Given this, the structure is reinforced to avoid that the natural frequencies of the same, be within the machine's operational range, that is, within the operational frequency range. A response pattern to a panel's vibration can have several spikes, each spike representing a natural frequency or panel resonant. The first natural frequency is the panel's lowest natural frequency. In a similar way, the second natural frequency is the panel's second lowest natural frequency. Operating the household appliance at a frequency close to the panel's natural frequency can result in a response of high vibration resonant to the panel, which causes the household appliance to vibrate and consequently, it is more desirable to have natural frequencies which are distant from the operational frequencies to avoid vibrations and noise.

If not all, then a great majority of household appliances have frequencies of operation. For example, in the case of washing machines for textiles, the main frequency of operation is given by the basket's rotation, which can rotate at high velocities. The frequency of operation of the textile washer is complemented with the rotation or agitation of an agitator, propeller or similar, as well as with the motor's operation and the clutch system. In the case of clothes washers, the main frequency of operation is given by the drum, as well as by the heaters and/or burners and the motor's work. The main frequency of operation of a microwave oven is given by the motor's operation, the wave emission and the rotation of the central plate. The frequency of operation of a dishwasher is given by the rotation of its water emitting arms, the water flow and its emission and the motor's operation. The frequency of operation of a convection oven is given by the motor which circulates forcibly the air within the oven. The frequency of operation of a vacuum cleaner is given by the motor and by the suction created by the motor. In each one of the cases, the frequency of operation causes the household appliance to vibrate and as a consequence of this vibration, it emits an undesired noise for the operator. For example, the washer's panels tend to vibrate, causing the washer to “walk” and make noise while walking. The clothes dryer tends to make noise when its drum is rotating. The microwave, the dishwasher, the convection oven and the vacuum cleaner, tend to make noise not only due to the motor's operation, but also due to the vibrations in their lateral panels, even when these are at a lesser scale.

Thus, as is known in the field, a press or inlay pattern increases the rigidity of the panels, which increases the harmony or natural frequency. Thus, if the rigidity of the panels is increased to a sufficient level, then the first natural frequency of the panels can be higher than any operational frequency of the household appliance. The problem with the great majority of the current cabinets, including those noted in the Background, is that the natural frequency of the panels is too close to the frequency of operation of the household appliances, especially in the clothes washers, so that problems in the area of noise and vibration present themselves. Thus it is desired to increase the natural frequency of the different household appliances for different reasons. For example, in the case of clothes washers it is desirable to increase the natural frequency, seeing as this will allow an increase in the angular velocity during centrifuge. The increase in angular velocity in the basket during centrifuge will allow the operator the advantage of being able to retrieve the more dehydrated textile articles, thus lessening the drying time. While it is desirable to increase the panels' rigidity, it is also desirable to maintain or even decrease the quantity of material used for the panels of the household appliance. The latter is taken into account given the cost of manufacture, that is, the denser the panel, the greater the production cost shall be for the household appliance. Given this, the tendency is for the thickness of the sheet to be lower. Thus, if the sheet laminates are not inlaid, it is very possible that the cabinet's natural frequency be very near or lower than the frequency of operation of the household appliance, which will cause vibration and with that, noise or walking of the household appliance.

The applicant has found that providing pressings or inlays to the cabinet's panels with a certain depth or elevation and with certain geometric forms, increases the first natural frequency as well as the maximum natural frequency of the cabinet's panels of a household appliance. It is known in the field that the wider the cabinet's laminate is—see General Electric's Mexico model Auge 90—and the deeper or higher the inlays are—see US publication No. 2005/0257326—the more the natural frequency of the panels increases. For example, US publication No. 2005/0257326 makes known pressings which vary between 3 to 11 millimeters (0.118 to 0.422 inches) in depth, see for example paragraphs (0027), (0030) and (0036); it is mentioned that at said depths or elevations there can exist several exceptions not yet mentioned. However, such depth or elevation (valleys and crests) are not wholly desirable. That is, even though it is agreed that it increases the panel's first natural frequency, the loss of space of for example, the tub of a clothes washer, or the increase of space in the operator's living space can reach considerable size. As an example, the loss of space in the tub can be translated as a smaller diameter for the tub, which leads to a smaller wash load of a washer or conversely, to an increase in foam generation during centrifuge. The smallest wash load could get to be of approximately 54 liters (3300 cubic inches). On the other hand, the increase in space of the household appliance can cause the consumer to not purchase given the size of the household appliance. Given the latter, the applicant worked only with certain depth and height dimensions, specifically with depths and heights varying approximately between 1.27 to 2.79 millimeters (0.05 to 0.115 inches). It is due to this reason, that the discovery made by the applicant is surprising to an expert in the field. That is, such as is highlighted in US publication number 2005/0257326, the deeper or the higher that the inlay is, the greater the rigidity which it lends the appliance. However, the applicant has discovered that though relevant, the depth or height dimension is not the only pattern to be followed. The applicant has found that decreasing the depth or elevation of the inlays or pressings and giving determined forms to the inlays or pressings, and possibly combining the forms in the same panel, the natural frequency of the cabinet is increased and thus increasing the operational velocity by 1.69 to 1.8 times the operational velocity of a base line cabinet (with the previous art pressings). This is achieved without the reduction of space or the space increase exposed in US publication number 2005/0257326. Considering that US publication number 2005/0257326 considerably increases the depth and height dimensions and as a result achieves—without mentioning the maximum—1.6 times the maximum rotational frequency, it is clear that the decrease in depth or elevations, should have decreased the natural frequency of the cabinet's panels, but having given the inlays a certain pattern, despite having decreased the depths and heights, the natural frequency of the cabinet's panels was increased, it being surprising that the figures used for the inlays should cause the increase in natural frequency.

Thus, in light of the latter, the applicant has focused on not losing space and increasing the cabinet's natural frequency. This has been achieved by giving the pressings or inlays of the cabinets' panels certain shapes, whose forms are polygonal, preferably in forms of rhomboids or rhombus, as well as triangular forms and hexagonal forms. It is found that preferably, the combination of polygonal preferred forms and the triangular forms in a same cabinet have the surprising effect of increasing the operational velocity by 1.69 to 1.8 times, thus allowing, in the case of household washers a rotational velocity (RPM) 1.69 to 1.8 times greater than a household washer with base line.

Therefore, it is an aspect of the present invention, to provide a household appliance whose panels have pressings or inlays with determined forms and that the depth or elevation dimensions of said pressing or inlays not have repercussions on the space occupied by the household appliance, as well as the usable space within the household appliance.

Another aspect of the present invention is to provide a household appliance whose inlays or pressings on the panels, have determined forms which are polygonal.

Yet, another aspect of the present invention is to provide a household appliance whose inlays or pressings on the panels, have determined forms which are rhomboidal or rhombus.

Another aspect of the present invention is to provide a household appliance whose inlays or pressings on the panels, have determined forms which are triangular.

Another aspect of the present invention is to provide a household appliance whose inlays or pressings on the panels, have determined forms which are hexagonal.

Another aspect of the present invention is to provide a household appliance whose inlays or pressings on the panels, have determined forms which are a combination of polygonal, especially rhombus and/or rhomboidal and triangular forms.

Another aspect of the present invention is to provide a household appliance whose inlays or pressings on the panels, have determined forms which are a combination of hexagonal and triangular forms.

Another aspect of the present invention is to provide a household appliance whose operational frequency is at least 1.69 times higher than that of the base line.

BRIEF DESCRIPTION OF THE FIGURES

The particular characteristics and advantages of the invention, as well as other objectives of the invention, shall become apparent from the following description taken into context with the accompanying figures which:

FIG. 1 is a resonance transmissibility chart, graphing transmissibility against a frequency rate.

FIG. 2 is an exploded view in perspective of a cabinet of the base line.

FIG. 3 is a modal view from an upper perspective of the base line cabinet with an operational frequency of 10.29 Hz.

FIG. 4 is a modal view from a perspective of the base line cabinet with an operational frequency of 10.29 Hz.

FIG. 5 is a modal view from an upper perspective of the base line of a second cabinet with an operational frequency of 9.69 Hz.

FIG. 6 is a modal view from a perspective of the base line of a second cabinet with an operational frequency of 9.69 Hz.

FIG. 7 is a view in perspective of a first embodiment, combining the teachings of previous art with a new form of pressing on the backside of the cabinet.

FIG. 8 is a view in perspective of a modal analysis of the cabinet in FIG. 7 at an operational frequency of 11.58 Hz.

FIG. 9 is a view in perspective of a washer for textiles with pressings on the cabinet's laterals and pressings on the back-side of the cabinet.

FIG. 10 is a back side view of a clothes washer with the second sub-version of the embodiments.

FIG. 11 is an exploded view in perspective of a first sub-version of the embodiments.

FIG. 12 is an exploded view in perspective of a second sub-version of the embodiments.

FIG. 13 is an upper view in perspective of a second embodiment of the panel of a household appliance.

FIG. 14 is an upper view in perspective of a third embodiment of the panel of a household appliance.

FIG. 15 is an upper view in perspective of the fourth embodiment of the panel of a household appliance.

FIG. 16 is an upper view in perspective of the fifth embodiment of the panel of a household appliance.

FIG. 17 is an upper view in perspective of the sixth embodiment of the panel of a household appliance.

FIG. 18 is an upper view in perspective of the seventh embodiment of the panel of a household appliance.

FIG. 19 is an upper view in perspective of the eighth embodiment of the panel of a household appliance.

FIG. 20 is an upper view in perspective of the ninth embodiment of the panel of a household appliance.

FIG. 21 is an upper view in perspective of the tenth embodiment of the panel of a household appliance.

FIG. 22 is a view of a modal analysis in perspective of the cabinet in FIG. 7 at an operational frequency of 21.02 Hz.

FIG. 23 is a view of a modal analysis in perspective of the cabinet in the fifth embodiment at an operational frequency of 17.23 Hz.

FIG. 24 is a view of a modal analysis in a lateral perspective of the cabinet in the fifth embodiment at an operational frequency of 19.41 Hz.

FIG. 25 is a view of a modal analysis in a backside perspective of the cabinet in the fifth embodiment at an operational frequency of 19.41 Hz.

FIG. 26 is a comparative graph of the maximum natural frequencies of the different panels of a cabinet of a washer for textiles of the base line and of a washer for textiles which has been modified according to the present invention in view of the basket's rotational velocity (RPM).

FIG. 27 is a comparative graph of the first natural frequencies of the different panels of a cabinet of a washer for textiles of the base line and of a washer for textiles which has been modified according to the present invention in view of the basket's rotational velocity (RPM).

DETAILED DESCRIPTION OF THE INVENTION

The following description shall be exemplified in a general manner for household clothes washers, however, as was previously mentioned, this invention is intended for all household appliances in general and can be used for all household appliances, among which can be clothes washers, clothes dryers, dishwashers, ovens, stoves, microwave ovens, refrigerators, fans and air conditioners among others.

It is known that the natural frequency of a mechanical system is a measurement of the rigidity present in the system through the following:

ω_n=(k/m)^0.5

Where:

K=rigidity of the system

M=mass of the system

In a way such that, if the mass remains unaltered and the rigidity of cabinet 1 is increased, then it follows that the natural frequency of the cabinet will also increase. The inlays made within the present application are made to maintain the same mass of the system, without however, modifying the rigidity of the cabinet.

FIG. 1 shows a resonance graph. Specifically a resonance transmissibility diagram in view of the frequency is shown. The graph shows that the lower the coefficient of the shock absorption δ the higher the transmissibility maximum curve will be. When the coefficient of the shock absorption δ is null, there is infinite resonance transmissibility. Given that the objective is to lower the resonance transmissibility, the coefficient of the shock absorption δ should be increased. As is shown in the graph, a clothes washer under the inner code of the applicant PM, which does not possess the inlays of the present invention but does have the inlays of previous art, at 670 revolutions per minute is found to be within an initial work range, while at 850 revolutions per minute, it is found to be within the final work range. With the inlays of the present invention, the cabinets are within the work range proposed in FIG. 1 with a rotational velocity of the sub-washer varying between 1300 revolutions per minute and 1500 revolutions per minute. Similarly, a low frequency rate has been selected for the work zone, to avoid excessive vibrations. Thus with the previous limitations in mind, the forms of the inlays of the present application were arrived at.

The inlays made in the present application, are made as examples, crests and/or valleys. That is, the crests are raised areas which when the manufacture of the laminate is complete, they appear as raised patterns on the outer part of the household appliance. Likewise, the valleys are grooved areas that when the manufacture of the laminate is completed, they appear as sunken patterns on the outer part of the household appliance. It is possible to combine on the same laminate both crests and valleys, and it is also possible to use in a laminate only crests or valleys. For the purposes of this description, inlay can be referred to randomly as a crest or as a valley, or to the combination of crests and valleys on the surface of a laminate. For the purposes of this description, depth can refer to the length or dimension of a crest or a valley.

Preferably, the laminates which form the lateral panels and the back panels are metal laminates, specifically steel with a thickness varying between 0.5 to 1.0 millimeters. Other thicknesses can be used. As is known in the art, increasing the thickness of the laminates increases the natural frequency of the panel. Other materials can be used, such as aluminum, galvanized steel, alloys, plastics or other components.

The depth of the grooves or the elevation of the inlays used for the experiments by the applicant varied between 1.27 to 2.79 millimeters (0.05 to 0.115 inches). The area of the laminate affected by the inlay is an important factor for the increase of the natural frequencies, specifically; the larger the area affected by the inlays, the better the improvement shall be of the effect to reduce noise and vibration. Thus, it is preferable to leave the minimum frame area or step area between the inlays and the border of the laminate, such as varying between 38.1 and 63.5 millimeters (1.5 to 2.5 inches). However, the area can vary, and it could be that the minimum frame area or step area be null.

Generally, and such as is shown in FIGS. 9, 10, 11 and 12, the cabinets of a household appliance are hexahedrons, specifically formed by four or five solid faces and one hollow face. The solid faces are two lateral panels 2, 3, a front panel 6, a back panel 4, and occasionally, a lower panel 7. The hollow face is an upper face 8, where a lid is placed which can have another figure. Given the form, it is common that the cabinet 1 of the household appliance has eight corners, four upper and four lower. The union between the panels can have different means of joints, such as can be by mechanical joints. Depending on the model of the household appliance, some components can be removed or can be substituted by others. Such as is the case in the back panel 4 of the household washer for textiles, that in some of the models this panel can be formed by two elements or merely by one element. That is, the back panel can be formed by a small backrest 9 connected to the folds of the lateral panels 2, 3 by means of suspenders and the space that remains is covered by a backrest made of laminate 10 joined by mechanical means to the lateral folds of the cabinet 1, the backrest laminate 10 can be a laminate with inlays. The latter can be seen in FIGS. 9, 10 and 11. If the back panel is formed by only one element, the back panel is a backrest with complete inlay 11 joined in a similar way by mechanical means to the lateral panels 2, 3. The latter can be seen in FIG. 12. The cabinet 1 can be formed by a single steel laminate sheet, where the inlays can be initially placed, and afterwards bent to form the cabinet 1 in this way, forming a seam which is joined by mechanical means on at least one side of the cabinet's 1 back panel 4.

FIGS. 2 and 6 show a cabinet 1 of the previous known art of a clothes washer, that is to say, a washer with a base line. Specifically in this cabinet a pair of longitudinal inlays 5 can be noticed on the lateral panels 2, 3 of the cabinet and on the back panel 4 of the cabinet 1. From previous art it was known that inlaying the lateral panels 2, 3 of the cabinets 1, specifically at least one panel of the cabinet's 1, and the back panel 4 of the cabinet 1, would increase the natural frequency of the cabinet 1, so that the operational frequency could be increased. It is also known that the more reliefs or the deeper the inlays 5 are placed, the higher the natural frequency that the cabinet 1 shall have. FIGS. 3 and 4 show a cabinet measuring 24 inches which has a first natural frequency of 10.29 Hz which is approximately equivalent to 617.4 revolutions per minute. As can be appreciated in the figures, the cabinet 1 did not have operational frequencies which were considerably greater than the natural frequencies and thus did not lead to “walking” of the clothes washer. However, in FIGS. 4 and 5 the same experiment was conducted in a cabinet measuring 27 inches reaching a first natural frequency of 9.69 Hz which is equivalent to 581.4 revolutions per minute where it is noted that the operational frequencies were considerably greater than the first natural frequency, which caused the cabinet 1 vibration and “walking”. The tendency in clothes washers is for the washer's basket to turn between 900 to 1400 revolutions per minute, so that, it is clear that a cabinet 1 of a clothes washer with two longitudinal inlays 5, as was shown in the previous art, are not sufficient to turn the sub-washer to 900 revolutions per minute.

First Iteration (FIGS. 7 and 8)

As an initial experiment by the applicant, a cabinet 1 with the conventional inlays from the previous art on the lateral panels 2, 3 was provided and modifying the back panel 4 so that it would have, in its center, a pressing or inlay 5 in a substantially rhombus figure and that on the lateral panels of the inlay in a substantially rhombus figure some inlays in substantially triangular forms are provided, in such a way that when the whole pattern is seen, a form substantially rectangular or square can be seen. The depth of the inlays for this iteration varied between 1.52 to 2.54 millimeters (0.06 to 0.1 inches). With the previous embodiment, a first natural frequency of the 24 inch cabinet was attained which varied between 11.58 Hz and 14.096 Hz which is equivalent to approximately between 694.8 to 845.76 revolutions per minute. With the previous embodiment, a first natural frequency of the 27 inch cabinet was attained which varied between 11.18 Hz and 13.57 Hz which is equivalent to approximately between 670.8 to 814.20 revolutions per minute. In FIG. 8, a conventional back view in perspective can be appreciated of the cabinet's modal view. The modal view shows that during the cabinet's 1 operation, the first natural frequency of the cabinet's, specifically the first natural frequency of the lateral panels 2, 3 is substantially lower than the natural frequency of the back panel 4. The previous experiment allowed the applicant to realize that a rhombus and/or triangular from for the inlays, would increase the cabinet's 1 natural frequency. Specifically, the improvements with the inlay in a substantially rhombus form on a laminate, as well as the inlays substantially in four triangles on the sides of the inlay in a shape substantially rhombus, allow for the reduction of vibration and noise problems in high operating frequencies.

Second Iteration (FIGS. 12 and 13)

Keeping the previous in mind, the lateral panels 2, 3 were modified so that they would have inlays in rhombus form at the center and four triangular formed inlays on the sides of the inlay in a rhombus form. The back panel 4 was allowed to remain in a substantially similar form to that of the first iteration. The area occupied by the inlays was substantially similar to the area occupied by the inlays of the first iteration. The depth of the inlays for this second iteration was of 1.52 millimeters (0.06 inches). With the second iteration, a first natural frequency of the 24 inch cabinet was reached of 18.24 Hz which is equivalent to approximately 1094.4 revolutions per minute. Through the previous, the applicant realized that modifying at least three of the cabinet's faces, that is, inlaying at least three panels of the cabinet 1, specifically the two lateral panels 2, 3 and the back panel 4 with the provided forms, affects the natural frequency of the cabinet.

Third Iteration (FIG. 15 Combined with the Back Panel in FIG. 12)

The lateral panels 2, 3 were modified so that the inlay in rhombus form could be a crest and the four inlays in triangular forms could also be crests. The back panel was allowed to remain in substantially similar form to that of the first iteration. The area occupied by the inlays is greater than the area occupied by the inlays of the first iteration. The depth of the inlays for this second iteration was 1.52 millimeters (0.06 inches). With the third iteration, a first natural frequency of the 24 inch cabinet was reached of 18.31 Hz which is equivalent to approximately 1098.6 revolutions per minute. The improvement was credited to the increase in the area of occupation of the inlays. To a lesser degree, the improvements were attributed to the inlays being in a crest.

Fourth Iteration (FIG. 13 in Combination with the Back Panel in FIG. 12)

The area of occupation for the inlays 5 was greater than the area of occupation of the inlays in the second iteration. The depth of the inlays for this second iteration was 1.78 millimeters (0.07 inches). With the fourth iteration, a first natural frequency of the 24 inch cabinet was reached of 19.29 Hz which is equivalent to approximately 1157.4 revolutions per minute. The improvement was attributed to the inlays' area of occupation and partly, to the modification to the depth of the inlays.

Fifth Iteration (FIG. 14 in Combination with the Back Panel in FIG. 9, 10 or 11)

The applicant modified the figure of the lateral panels 2, 3 for this iteration. Specifically, at the panel's center an inlay is provided substantially in rhombus form, whose lateral sides are formed by inlays in substantially rectangular forms. On the lateral sides of the inlay in substantially rhombus form, that is the lengths of each one of the rectangles, inlays are provided in substantially triangular forms, in such a way, that when the pattern is seen as a whole, a form substantially square or rectangular can be visualized. The back panel 4 was modified according to FIGS. 9, 10 and 11. Specifically it is composed of two parts. The upper part is substantially rectangular. The lower part is composed of a hexagon at the center, the hexagon having an inlay in a substantially “v” shape. On the upper part, surrounding the upper parts in a substantially “V” shape, an inlay in triangular form is provided. One each one of the lower sides of the form substantially in “V” form, an inlay in triangular form is provided. The area of occupation of the inlays was substantially similar to the area of occupation of the inlays in the third iteration. The depth of the inlays for this second iteration was 2.54 millimeters (0.01 inches). With the fifth iteration, a first natural frequency of the 24 inch cabinet was reached of 19.41 Hz which is equivalent to approximately 1164.6 revolutions per minute. The improvement was attributed to the depth of the inlays and partly to the modification in the form of the inlays.

Sixth Iteration (FIG. 16 in Combination with the Back Panel in FIG. 9, 10 or 11)

The form of the inlays was substantially similar to the fifth iteration, however the edges of the rhombus, of the rectangles and of the triangle are simpler since the entrance angle of the die is softer. The occupation area of the inlays was substantially similar to the occupation area of the inlays of the fifth iteration. The back panel is substantially similar to the back panel of the fifth iteration. The depth of the inlays for the lateral panels for this sixth iteration was 1.78 millimeters (0.07 inches), while the depth of the inlays for the back panel of this sixth iteration was 2.54 millimeters (0.1 inch). With the sixth iteration, a first natural frequency of the 24 inch cabinet was reached of 21.26 Hz which is equivalent to approximately 1275.6 revolutions per minute. The improvement was attributed in part to the inlays' area of occupation and partly, to the modification to the forms of the inlays.

Through the varying configurations of inlays in rhombus forms and in triangular forms in FIGS. 16 through 18 and 18 through 21, it was possible to achieve the 21 inch cabinet's natural frequency with the depth of the inlays varying between 1.52 and 2.54 millimeters (0.06 to 0.1 inches) to be between 21.50 and 23.97 Hz which is equivalent to between 1290 and 1438.2 revolutions per minute, while it was possible to achieve for the 27 inch cabinet's natural frequency with the depth of the inlays varying between 1.52 and 2.54 millimeters (0.06 to 0.1 inches) to be between 20.23 and 23.10 Hz which is equivalent to between 1213.8 and 1386 revolutions per minute.

FIGS. 22 through 25 are comparative modal figures of the different embodiments presented. Specifically, FIG. 20 is a modal diagram of the first iteration described above in its natural frequency. FIG. 21 is a modal diagram of the fifth iteration described above in its natural frequency. FIG. 22 is a front modal diagram of the sixth iteration described above in its natural frequency. FIG. 23 is a back modal diagram of the sixth iteration described above in its natural frequency.

FIG. 26 shows a graph with the results of the impact. Specifically, it is a comparative between the faces of the cabinet versus the velocity in revolutions per minute on each one of the cabinets' faces to obtain the maximum natural frequency of each one of the faces. The comparison takes place between the cabinet of the present invention (GTO) and that of the base line (LB). It should be recalled that the base line only has a pair of inlays on each one of the lateral faces, and that neither the back face nor the front face contain any type of inlay. It should also be recalled that the first natural frequency is different than the maximum natural frequency. It was found that the front face of the LB had a maximum frequency of 22.51 Hz, corresponding approximately to 1350.6 revolutions per minute. The right lateral face of the LB had a maximum frequency of 21.12 Hz, corresponding approximately to 1267.2 revolutions per minute. The left lateral face of the LB had a maximum frequency of 17.34 Hz, corresponding approximately to 1040.4 revolutions per minute. Finally, the back face of the LB had a maximum frequency of 15.74 Hz, corresponding approximately to 944.4 revolutions per minute. Conversely, it was noted that the front face of the GTO had a maximum frequency of 25.70 Hz, corresponding approximately to 1542 revolutions per minute. The right lateral face of the GTO had a maximum frequency of 27.29 Hz, corresponding approximately to 1637.4 revolutions per minute. The left lateral face of the GTO had a maximum frequency of 27.29 Hz, corresponding approximately to 1637.4 revolutions per minute. The back face of the GTO had a maximum frequency of 25.70 Hz, corresponding approximately to 1542 revolutions per minute. Thus, the LB average is 19.17 Hz, which is equivalent to approximately 1150.65 revolutions per minute, while the GTO average is 26.49 Hz, which is equivalent to approximately 1589.7 revolutions per minute. The improvement between the maximum natural frequencies of the GTO in comparison to the maximum natural frequency of the LB is approximately 138.15% higher.

FIG. 27 shows a graph with the results of packaging. Specifically, it is a comparison between the faces of the cabinet versus the velocity in RPM in each one of the faces of the cabinet to obtain a first natural frequency of each one of the faces. The comparison takes place between the cabinet of the present invention (GTO) and that of the base line (LB). It should be recalled that the base line only has a couple of inlays on each one of the lateral faces and that neither the back face nor the front face have any type of inlay. The first natural frequency of the front face of the LB was found at 18 Hz, equivalent approximately to 1080 revolutions per minute. The first natural frequency of the right lateral face of the LB was found at 11 Hz, equivalent approximately to 660 revolutions per minute. The first natural frequency of the left lateral face of the LB was similarly found at 11 Hz, equivalent approximately to 660 revolutions per minute. The first natural frequency of the back face of the LB was found at 9 Hz, equivalent approximately to 540 revolutions per minute. Conversely, the first natural frequency of the front face of the GTO was found at 26 Hz, equivalent approximately to 1560 revolutions per minute. The first natural frequency of the right lateral face of the GTO was found at 22 Hz, equivalent approximately to 1320 revolutions per minute. Similarly, the first natural frequency of the left lateral face of the GTO was found at 22 Hz, equivalent approximately to 1320 revolutions per minute. The first natural frequency of the back face of the GTO was found at 18 Hz, equivalent approximately to 1080 revolutions per minute. Thus, the average of the first natural frequency in the LB was 12.25 Hz which is approximately equivalent to 735 revolutions per minute, while the average for the first natural frequency for the GTO was 22 Hz which is approximately equivalent to 1320 revolutions per minute, so that the improvement between the maximum natural frequencies of the GTO in comparison to the maximum natural frequency of the LB is approximately 179.59% higher.

Thus, as is shown above, in the case of household washers, in light of the inlays substantially in the forms of rhombus and the inlays substantially in the forms of triangles, the sub-washer can operate at higher velocities without having the phenomenon of membrane vibration present, as well as the phenomenon of resonance being present. Specifically, the sub-washer can operate up to 44.31% faster in revolutions per minute without any of these phenomenons being present. That is, in other words, the operational velocity, and as follows, the operational frequency can reach 1.79 times more in the GTO than in the LB.

It is worth mentioning again that if inlays with greater depth are provided, such as is done in the previous art, specifically US publication number 2005/0257326, both the first natural frequency as well as the maximum frequency should increase. This is due to the increase in mass of the system, as well as the resistance of the system. It is also logical that increasing the thickness of the cabinet's faces increases the mass of the system and as a consequence both the first natural frequency as well as the maximum natural frequency also increase.

In the same manner, it is worth highlighting that the numbers of pressings is not an important factor in increasing natural frequency. Specifically, a cabinet was created for the purposes of experimentation which had inlays such as are shown in FIG. 13, in which the lateral faces of the cabinet have a square pattern. It was found that the first natural frequency of the cabinet was 10.26 Hz which is equivalent to approximately 621.6 revolutions per minute.

Alterations to the structure described through this description, can be foreseen by those experts in the field. However, it should be understood that the present description is related with the preferred embodiments of the invention, which is merely for illustrative purposes only and should not be construed as a limitation of the invention. All modification which do not depart from the spirit of the invention are included within the body of the attached claims.

Cabinet Pressing

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