Freestanding Appliance With Break-open Door

Abstract

A freestanding appliance such as a portable dishwasher having a swing-down access door has means which resists opening of the door beyond its normally open horizontal position and which yields when a downward force is imposed upon the door which exceeds that downward force imposed upon the door in its normal use and which would tend to cause the appliance to tip but for the yielding, which permits the door to swing down until stopped by the floor.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention pertains to the art of freestanding appliances which have swing-down doors upon which sufficient force may be accidentally imposed to tip the appliance.

2. Description of the Prior Art

U.S. Pat. Nos. 3,150,904, 3,150,905, and 3,322,480 are examples of the direction which the prior art of which I am aware has taken in providing means to prevent tipping of those freestanding appliances such as portable dishwashers which have a door on the front of the cabinet which swings down for access purposes. The concept with which each of these deals is the provision of means which moves out into a bracing attitude when the access door is swung downwardly to its open horizontal position, and which moves back into a retracted position when the door is moved to its closed vertical position. Another way to prevent tipping is to shift the front wheels forwardly but this arrangement is not very attractive since the front wheels are then visible. The requirement of tipping avoidance arises from Underwriter's Laboratory, and calls for the cabinet of a portable dishwasher with a swing-down door holding its position on a floor when a force of about 50 pounds is imposed on the outer edge of the door when the door is in its fully open horizontal position. So far as I know, the only approach taken to prevent tipping and satisfy the Underwriters requirements are those mentioned above.

SUMMARY OF THE INVENTION

The concept according to my invention, and as embodied in a swing-down door arrangement on a freestanding appliance such as a dishwasher, is to provide means for resisting the downward pivoting of the door beyond its normally open position, but with the means being yieldable to permit the door to pivot downwardly past the normally open position upon the downward application upon the door of a break-open force of a degree of which is greater than that downward force imposed upon the door in its normal use, but is less than that downward force which would tip the appliance if the yieldable arrangement were not present. Thus, instead of bracing the cabinet so that it will not tip when the 50 pounds is applied, the door holds it in normally open position when the normal downward forces to which it is subjected are applied thereon, but yields and starts to swing downwardly when that normal downwardly force is exceeded by a predetermined amount.

I consider that my invention has its current most important application to front loading portable dishwashers and accordingly it will be described in connection therewith, but is it to be understood that the invention may also be applied to other appliances such as freestanding ranges for example.

DRAWING DESCRIPTION

FIG. 1 is a partly broken side elevational view of a portable dishwasher having a door arrangement according to the invention;

FIG. 2 is a side elevational view of the lower part of the dishwasher of FIG. 1 with the door in a normally open position;

FIG. 3 is a view similar to FIG. 2 but showing the door pushed past its normally open position due to the imposition of a downward force thereupon greater than that to which the door is subjected in normal use;

FIG. 4 is a perspective view in detail of one type of detent means which may be used to resist the opening of the door beyond its normally open position;

FIG. 5 is a fragmentary side elevational view of the side of the dishwasher opposite to that shown in FIGS. 1 through 4 and illustrating one type of counterbalancing means which may be used; and

FIG. 6 is a view similar to FIG. 5 but showing the door in its normally open position.

DESCRIPTION OF CURRENTLY PREFERRED EMBODIMENT

A freestanding appliance having a swing-down door such as one type of portable dishwasher is shown in the drawing for the purpose of illustrating an embodiment of the invention. The dishwasher includes an outer finished panel cabinet 10 having an inner washing tub 12 supported upon a pair of front legs 14 and rear legs 16, which are braced near their lower ends by the channels 18 extending from front-to-rear on both sides of the dishwasher. Both the front and rear ends of the channels have casters 20 mounted thereon so that the dishwasher can be freely moved. The casters are located so that with the side panels and front skirt (not shown) in place, the casters are substantially hidden from view.

The front vertical side of the cabinet and tub is open and provided with a door 22 hinged along its lower edge so that it may be swung down from its closed vertical FIG. 1 position to its normally open, generally horizontal, FIG. 2 position. The left side (as viewed from the front of the dishwasher) has a hinge member 24 (FIGS. 1-3) which secures the lower edge of the door to the tub and cabinet structure, and the right side has a hinge member 26 performing the same function (FIGS. 5 and 6). The left side mechanism of FIGS. 1-3 illustrates one currently preferred mechanism for carrying out the invention, while the mechanism on the right side mainly performs a counterbalancing function for the door. It is noted that the mechanisms on both sides may take forms which from an appearance standpoint are substantially different from that shown, it only being necessary in accordance with the invention that the arrangement by which the door is held in its normally open position be of a character permitting the door to break downwardly past that normally open position upon the application of a force greater than that imposed upon the door in its normal use. While the arrangement of hinge and springs on the right side of the dishwasher (FIGS. 5 and 6) is such that the major part of the counterbalancing is accomplished by the right side arrangement, some counterbalancing is also exerted by the arrangement on the left side which incorporates the structure which permits the door to break open from its normally open position in accordance with the invention. It is noted that "break open" is used in the sense of moving down past a normally open position either gradually or relatively abruptly, although the latter mode of operation is currently preferred.

Apart from the break-open feature, the structure and operation of the dishwasher is conventional. Thus, as indicated in FIG. 2, when the door 22 is open to its normally open position, the lower rack 28 may be pulled out to rest upon the door for loading and unloading dishes. A lever arm 30 has one end pivotally attached at point 32 to the door and its opposite end attached to a tension spring 34 which extends downwardly and rearwardly for connection to a rear leg 16. The lever arm also has a hook portion 36 which, as the door 22 is moved from its closed to its normally open FIG. 2 position, moves into engagement with detent means generally designated 38. The relationship of the hook and detent means when the door is in its normally opened position is best seen in FIG. 4.

The detent means generally designated 38 includes a mounting bracket 40 in the form of an angle secured to the tub and leg assembly, the outwardly projecting leg of the angle carrying a plastic guide block 42 having an opening 44 in its horizontal face into which is inserted a generally vertically extending catch member 46. The catch member has an eye 48 at its upper end into which the hook 36 of the lever 30 is received when the door 22 is moved to a normally open position. The lower end of the catch member is attached to a tension spring 50 which has its lower end connected near the bottom of leg 14. The intermediate part of the catch member has a forwardly offset portion 52 which, when the catch member is in its lowered normal position, engages a shoulder 54 at the bottom of the guide block.

The spring 34 attached to the bent lever 30 performs a counterbalancing function as will be apparent by noting the elongation of the spring (FIG. 2) after the door has been moved from a closed to a normally open position, and also serves to guide the rear end of the lever 30 so that the hook portion 36 will be directed into the eye 48 of the catch member. It will be appreciated that when the door is in its normally open position as shown in FIG. 2, the spring 34 on the left side of the dishwasher, as well as the springs 56 and 58 on the right side of the dishwasher all serve to resist opening of the door beyond the normally open position. However, their resistance is not of a positive character since their elongation is generally linear with the pull upon them. The detent means 38 provides the most significant resistance by the engagement of the shoulder 52 against the guide block edge 54, coupled with the spring 50 holding the catch member in that disposition. However, upon the imposition of a downward force upon the door greater than a maximum force imposed in the normal use of the dishwasher (such as a full load of dishes on the lower rack extended to its outermost position), the resistance of the door to further downward movement will yield by virtue of the shoulder 52 being pulled past the lower edge 54 of the guide block, which permits the catch member 46 to move upwardly through the opening 44 of the guide block against the pull of the spring 50.

It will be appreciated that for the door to swing downwardly beyond its normally open position, the rear end of the bent lever 30 must move upwardly since the upper curved edge 60 of the hinge member 24 engages with the lower edge of the lever 30 at an intermediate location therealong when the door reaches its normally open position. The resistance to this elevation (presented mainly by the detent means, and to a lesser degree by the spring 34) is what prevents the door from breaking open from its normally open position unless a force is imposed downwardly upon the door which is in excess of that maximum downward force imposed upon the door in its normal use. It will be appreciated however that the yielding of the door must take place with a degree of force exerted upon the door which is less than that which would cause the cabinet to tip but for the yielding.

As noted before, the Underwriter's Laboratory has selected 50 pounds as that force which may be imposed upon the outer edge of the door in its normally open position without tipping the cabinet. As an example providing a basis for the selection of the springs and detent means to obtain operation in accordance with my invention, with a dishwasher of the general arrangement as shown (that is, with the location of the front casters relative to the remainder of the dishwasher), if the door were not pivotal upon its hinges beyond a normally open position, a force of about 27 pounds at the outer edge of the door would cause the cabinet to tip. With the springs and detent I propose for use in a dishwasher to be commercialized, a force of 16 pounds imposed at the outer edge of the door is sufficient to cause the detent means to yield so that the door can start to move downwardly. With an increasing force imposed upon the door after it yields, because of the increased tension of the various springs, at 21 pounds the door will have moved all the way down to a position where its outer edge contacts the floor upon which the dishwasher rests.

It will be appreciated that the selection of the springs and the resistance to yielding provided by the detent means will be determined in accordance with a number of factors, such as the weight of the dishwasher, the location of its center of gravity relative to the location of the front casters (which serve as the fulcrum location in tipping), and the lever arm dimensions for the various springs.

While I have illustrated one specific way of carrying out my invention, it will be appreciated that with the inventive concept in mind, other mechanical arrangements can be readily devised. For example, a detent or stop means to resist the yielding of the door beyond its normally open position may well be provided on both sides of the unit and in conjunction with counterbalancing means on both sides of the unit. Further, rather than using a frictional resistance type of detent, the yieldable resistance means could alternately for example comprise two compression springs which would work against the tail of the hinge member 24, with one spring being compressible with a substantially lesser force than the other spring so that as the door is swung down to its normally open position the first spring is compressed, and the tail of the hinge member moves into engagement with the second spring which requires a substantially greater force to initiate its compression. Also, specific detent means as such may be omitted and an additional spring be used to serve as the means to resist the downward movement of the door beyond its normally open position. It that case, the door would have a normally open position that would fall within a narrow range, and downward movement within that range and below it would be of a gradual character upon the application of a break-open force. The preferred arrangement however is to provide a reasonably positive stop position.

An arrangement according to my invention does result in the possibility of jarring a rack of dishes resting on the door if a sufficient downward force is imposed upon the door to move it down to the floor. However, the likelihood of this is reasonably remote since, as soon as the door starts to yield, it is evident to whomever may be pushing downwardly on it, and the natural tendency would be to then release the force. Furthermore, since the requirement of nontipping of the cabinet is a safety requirement, to prevent the cabinet from tipping over on a child for example, an arrangement according to my invention wholly satisfies such a requirement. Furthermore, in distinction with those arrangements which brace the cabinet to sustain at least 50 pounds, an arrangement according to the present invention precludes tipping of the cabinet regardless of the amount of force which is applied to the door. This is not so with respect to those arrangements which brace the cabinet.

Claims

I claim as my invention:

1. A portable, front loading dishwasher having a cabinet and including:

a swing-down door having a generally horizontal full open position for normal use of said dishwasher;

a member hingedly connecting said door to said cabinet and rotatable in accordance therewith;

a lever pivotally connected at one end to said door at a location along the edge of said door spaced from said hinge member, and in substantially the plane of said hinge member;

means for guiding said lever into engagement with said hinge member when said door is moved to its normally full open position so that said hinge member serves as a fulcrum for further movement of said lever;

a dish rack movable out onto said door when in said horizontal position;

counterbalancing means for said door;

means for resisting movement of said door downwardly past said normally full open position, said resisting means being yieldable to permit said door to be pivoted downwardly past said normally full open position upon the imposition of a downward force greater than that downward force imposed upon said door in normal use of said dishwasher, but less than that downward force which would tip said dishwasher if said resisting means were not yieldable, so that upon the application of an excessive downward force said door pivots downwardly as far as the floor upon which said dishwasher rests without said dishwasher tipping, said resisting means preventing movement of the other end of said lever about said fulcrum until said excessive downward force is imposed upon said door.

2. A dishwasher according to claim 1 wherein:

said resisting means includes, in part at least, detent means.

3. In a dishwasher according to claim 2 wherein:

said detent means includes a catch member biased downwardly and positioned to be engaged by said lever upon movement of said door to its normally full open position, so that said detent means must be moved upwardly against its bias by said lever means upon the pivoting of said lever means upon its said fulcrum when said door is moved open past its normally full open position.