Closure fasteners – Bolts – Swinging
Reexamination Certificate
1999-07-16
2001-09-18
Estremsky, Gary (Department: 3627)
Closure fasteners
Bolts
Swinging
C292S216000
Reexamination Certificate
active
06290270
ABSTRACT:
The invention relates to a door lock for an electrical household appliance, in particular for a dishwasher.
With electrical household appliances such as a dishwasher, the door lock may be installed both in the door and in the appliance casing. A hook is located on the other of the two parts in each case and, when the door is closed, is introduced into the lock and hooks in there.
Current door locks lock with either a force fit or a form fit.
A form-fit door-lock system is known, for example, for DE 43 17 135 C2. Form-fit systems are location-specific, i.e. the latching-in position of the locking hook is defined. In order to ensure that the door of the appliance seals well but can also be easily closed, the locking hook has to be adjusted precisely in terms of its longitudinal alignment. The tolerance level permissible here is relatively low. Adjustment is time-consuming and, in addition, incorrect adjustment results in a lot of time being lost during production.
A force-fit door-lock system is known, for example, from DE 195 40 843.8 and DE 43 43 975 C2. In such systems, as the door is closed, the hook engages in a mouthpiece of a so-called pivot flap and rotates the pivot flap. At the same time, a spring which is prestressed in the opening direction is compressed up to a changeover point, the spring then being relieved of pressure in the closing direction and thus closing the door and drawing it against the seal. The pivot flap provides just a relatively short lever arm, with the result that the force by which the door-lock system draws the door closed depends very precisely on the height position of the hook. Here too, hook-related tolerances pose problems.
DE 195 04 797 C2 describes a locking device for the door of a dishwasher, having a lever-like locking element which is connected to a gripping device which contains a latch.
The object of the invention is to provide a door lock which is intended for an electrical household appliance and does not have the abovementioned disadvantages as far as the hook-position tolerances are concerned.
The object is achieved according to the invention by a door lock for an electrical household appliance having a framework with an opening for a hook, a locking element, such as a locking lever (
12
) in the framework, and a locking spring which is arranged between the locking element and an abutment in the framework, it being the case that the locking spring is subjected to stressing when the door lock is in an open position, the door lock has a movable gripping device which is connected to the locking element and, when the door lock is in the open position, is pressed by the locking spring, at a contact location, against a part of the framework or in the framework, it being possible for said part of the framework to be, for example, of rigid design or to be designed as a roller, and thus prevents the spring from being relieved of stressing, and the gripping device has a gripping latch into which the hook can be guided as it comes in through the opening of the framework, and which has a contact surface on which the incoming hook presses and thus causes the gripping device to move, and the gripping device is formed such that, in the event of movement, it loses the contact with the contact location and the locking spring can thus be relieved of stressing.
When the locking spring is relieved of stressing, the locking element is moved, as is thus also the gripping device with the hook in the gripping latch. The door is thus closed. Since the locking spring does not have to act directly on the gripping device, that is to say the gripping of the locking hook and the closing operation itself are separate functions, the requirements to be met by the tolerance as far as the position of the hook is concerned are reduced to a considerable extent.
The locking spring may be subjected to stressing by a motor provided in the door lock, but the door lock preferably has an opening lever which can be pressed against the locking element, with the result that the locking spring is compressed when the opening lever is actuated. It is usually the case that, when a door is opened, an opening lever is guided toward the appliance body and, with this movement, the necessary force can easily be applied.
The locking element advantageously has a locking lever which can be pivoted about an axis. The locking spring advantageously presses on the locking lever at a location which is further away from the axis than the location at which the gripping device is connected to the locking lever, i.e. the locking-spring force acts on a larger lever than the hook when it engages in the gripping device.
The gripping device can preferably be rotated about an axis of rotation. In this case, the hook can be gripped particularly well since the opening of the gripping latch rotates such that it is no longer possible for the hook to escape out of the gripping device. A variant of the gripping device with a slide, however, is likewise possible.
During opening, the gripping device can be guided into its original rotary position again by the seal, or a special integrated set of springs, applying a force to the door and the hook being drawn out of the opening. However, the gripping device advantageously has a torsion spring which is subjected to stressing when the lock is in the locked position, with the result that, when the door is opened, the gripping device is moved into its original position by the torsion spring.
The gripping device advantageously has a circumference line which forms part of a circle about the axis of rotation and from which a sliding edge runs inward toward smaller radii at an angle of at least 450 from a tangent to the circumference line. The sliding edge advantageously runs toward a stop edge. If the gripping device butts against the contact location by way of the radial part of the circumference line, then it rotates, when a hook is introduced, without the locking element moving. If the sliding edge (of the gripping device) reaches an edge of the rigid part of the framework during rotation, the locking spring can be relieved of stressing and, with the movement of the locking element, the gripping device slides along the sliding edge until the movement is stopped, for example, by the stop edge. However, a surface in the framework (casing) may also serve as a stop for the locking element. In this case, the door is drawn against the seal via the locking element.
The sliding edge preferably runs radially in relation to the axis of rotation, and the stop edge is essentially perpendicular to the sliding edge.
The gripping latch is advantageously formed as a more or less radial, but eccentric recess in the circumference of the gripping device.
The door lock may also have two locking springs, for example in the case of a locking lever which is somewhat wider.
Alternatively, it is also possible for the locking element to be designed as a slide. Two locking springs advantageously press against the slide, and the gripping device is connected to the slide between the two springs.
REFERENCES:
patent: 1573866 (1926-02-01), Rogers
patent: 2138251 (1938-11-01), Lindstrom
patent: 2833578 (1958-05-01), Burke
patent: 3985023 (1976-10-01), Guth
patent: 4398747 (1983-08-01), Bernard
patent: 4497513 (1985-02-01), Saski
patent: 5440103 (1995-08-01), Martin
patent: 6048001 (2000-04-01), Miller
patent: 43 17 135 (1994-09-01), None
patent: 44 24 201 C2 (1996-05-01), None
patent: 43 43 975 C2 (1997-04-01), None
patent: 195 04 797 C2 (1997-04-01), None
patent: 195 40 843.8 (1998-07-01), None
Browning Clifford W.
Elektromanufactur Zangenstein Hanauer GmbH & Co. KGAA
Estremsky Gary
Woodard Emhardt Naughton Moriarty & McNett
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