1. Field of the Invention
The present invention pertains to the art of dishwashers and, more particularly, to a mechanism for shifting a lid of a drawer-type dishwasher between open and closed positions.
2. Description of the Related Art
In general, dishwashers having pull-out drawers are known in the art. In some cases, the dishwasher will include an upper, pull-out drawer forming an upper washing chamber for washing smaller objects such as glassware, utensils, small plates and the like, and a lower conventional-type dishwasher. In other cases, the dishwasher will include upper and lower pull-out drawers, or just simply include a single, pull-out drawer. In any event, the washing chamber of the pull-out drawer must be provided with a lid having a water-tight seal that prevents washing fluid from leaking out or otherwise escaping from the dishwasher during a washing operation.
Typically, the lid is pivotally mounted to a frame or housing of the dishwasher above the washing chamber. With this arrangement, when the drawer is withdrawn from the dishwasher, a mechanism elevates the lid relative to the washing chamber and, when the drawer is inserted back into the dishwasher, the mechanism lowers the lid onto the washing chamber. The mechanisms employed in the prior art take on many forms. For example, many mechanisms utilize a system of springs and linkages, while other systems employ motors, solenoids or linear actuators to raise and lower a lid. Still other mechanisms employ a system of cams and springs to operate the lid.
Despite the existence of lid operating mechanisms in the prior art, there still exists a need for a lid operating mechanism that effectively and efficiently shifts a lid of a drawer-type dishwasher between open and closed positions. More specifically, there exists a need for a simple, cost-effective lid operating mechanism that is easy to install and provides a consumer with reliable operation.
The present invention is directed to a drawer-type dishwasher including an outer housing, a washing tub shiftably mounted in the outer housing, a lid for selectively closing the washing tub and an operating mechanism that raises and lowers the lid as the washing tub is shifted into and out of the outer housing. In accordance with the invention, the operating mechanism includes a lifting slider slidably mounted in the outer housing and operatively coupled to a lifting spring, and a compression slider which is also slidably mounted in the outer housing and operatively coupled to a compression spring.
The lifting slider and compression slider are provided with corresponding lifting rollers and compression rollers that engage the lid. More specifically, the lid includes a top section, a rear section and opposing side sections, with each of the opposing side sections having a lower edge portion and an arcuate opening. The lower edge portion includes at least one recessed portion and at least one raised portion. The lower edge portion of the lid rides upon the lifting rollers while the compression rollers are arranged to travel in the arcuate slot. With this arrangement, as the washing tub is withdrawn from the outer housing, the lifting spring urges the lifting slider upward, thereby automatically raising the lid.
Conversely, as the drawer is inserted or shifted into the outer housing, a rear portion of the washing tub abuts the rear section of the lid, thereby causing the lid to shift horizontally. As the lid shifts horizontally, the compression rollers traverse the arcuate opening and urge the compression sliders downward. The compression sliders then force the lid into sealing relationship with the washing tub. The compression spring supplies sufficient force to overcome the lifting spring and provides a suitable seal about the washing chamber. The operating mechanism is also provided with an alignment aide to ensure a proper alignment between the lid and the washing tub. The alignment aide includes an alignment element arranged on the rear wall of the washing tub and an aligning member arranged on the rear section of the lid. As the washing tub abuts the lid, the aligning member nests into the alignment element to properly position the lid relative to the drawer.
Additional objects, features and advantages of the present invention will become more readily apparent from the following detailed description of a preferred embodiment when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.
With initial reference to
In accordance with the embodiment shown, upper drawer 16 includes a front wall 20, a rear wall 21 (see
Referring to
At this point, the description of operating mechanism 75 will proceed with describing structure incorporated into side wall 44 of outer housing 40 and it should be understood that corresponding structure is provided in side wall 43. Referring to
In further accordance with the invention, operating mechanism 75 includes a lifting spring 190 that extends between and abuts lifting sliders 143 and 144. Lifting spring 190 is secured to side wall 44 by a tensioning block 192. Tensioning block 192 can be vertically re-positioned along a support 193 so as to set a desired tension in lifting spring 190. In addition to lifting spring 190, operating mechanism 175 includes a compression spring 196 that extends between and acts upon compression sliders 147 and 148. In a manner similar to that described above, compression spring 196 is secured to side wall 44 by a tensioning block 198 that can be selectively, vertically re-positioned along support 193 to establish a desired tension in compression spring 196.
In still further accordance with the invention, each lifting slider 143, 144 includes a corresponding lifting spring support 204, 205. As shown, lifting spring 190 abuts lifting spring supports 204, 205 to urge lifting sliders 143, 144 upward to raise lid 50. Each lifting slider 143, 144 also includes a corresponding lifting roller 208, 209 which supports lower edge portion 109 of lid 50. Certainly, without a corresponding opposing force, lifting sliders 143 and 144 would maintain lid 50 in a constant raised position. In contrast, compression sliders 147, 148 include compression spring supports 234 and 235 which are acted upon by compression spring 196 to counteract the force applied by lifting spring 190. In a manner similar to that described above, compression sliders 147 and 148 are provided with corresponding compression rollers 240 and 241 which are positioned in arcuate openings 132 and 133 respectively. As will be discussed more fully below, compression rollers 240 and 241 travel within arcuate openings 132 and 133 as lid 50 transitions between the raised and lowered positions.
Of course, it is important to establish proper positioning of lid 50 in order to ensure a proper seal. Towards that end, operating mechanism 75 includes an alignment aide 249 best shown in
Having described a preferred construction of operating mechanism 75, reference will now be made to
In accordance with the most preferred form of the invention, as drawer 16 is guided into outer housing 40, rear wall 21 contacts rear section 85 of lid 50. More specifically, as drawer 16 contacts lid 50, aligning member 296 and aligning element 256 interengage to ensure proper alignment. At this point, lid 50 becomes constrained against rear wall 21 of drawer 16 such that, as drawer 16 moves further aft in outer housing 40, so does lid 50. In any event, as drawer 16 continues to move into outer housing 40 towards a fully retracted position, the horizontal displacement of drawer 16 forces lower edges 108 and 109 of lid 50 to travel along lifting rollers 208 and 209. Likewise, compression rollers 240 and 241 travel within arcuate slots or openings 132 and 143. As lid 50 nears the fully closed or retracted position, raised portions 112 and 113 force lifting sliders downward against the tension provided by lifting spring 190, thereby causing a vertical translation in lid 50.
Once lid 50 has sufficiently translated vertically and a seal is established between top section 84 and washing tub 28, lifting sliders 143 and 144 force lifting spring 190 downward to a point at which a pre-load in spring 190 is overcome, allowing compression spring 196 to shift compression sliders 147 and 148 downward to a final position. The travel in lifting sliders 143 and 144, as well as compression sliders 147 and 148, acts as tolerance accumulators for the overall operating mechanism 75. It should also be noted that, as lid 50 travels along lifting rollers 208 and 209, a detent portion (not separately labeled) provided on lower sections 108 and 109 is reached. Once the detent point is reached, horizontal forces on the system are reversed. In other words, once the detent is passed, drawer 16 no longer requires a force to push it closed, rather drawer 16 will automatically shift to the fully closed position and seat upon drawer 16.
At this point it should be understood that the present invention provides a simple and cost effective operating mechanism that efficiently transitions a lid of a drawer-type dishwasher between open and closed positions. More specifically, the present invention establishes an easy to install, low maintenance activating system designed to have a prolonged service life for the dishwasher. Although described with reference to a preferred embodiment of the invention, it should be readily understood that various changes and/or modifications can be made to the invention without departing from the spirit thereof. In general, the invention is only intended to be limited by the scope of the following claims.
The present application is a divisional of U.S. patent application Ser. No. 11/500,986, filed Aug. 9, 2006 entitled “Lid Operating Mechanism for a Drawer-Type Dishwasher.”
Number | Date | Country | |
---|---|---|---|
Parent | 11500986 | Aug 2006 | US |
Child | 12775052 | US |