Patent Application
20130300273
The invention is directed to a hinge assembly for a domestic appliance that reduces or eliminates noise and damage caused by a spring inside a cylinder.
An example of an application for the invention is a hinge assembly used with a door of a domestic appliance.
Many domestic appliances, such as built in ovens, have one or more doors that swing open about a horizontal axis such that the door swings downward into an open position. Such a door is often heavy and uses springs of significant strength to counteract a portion of the weight of the door so that it is easier for a user to open and close the door. These springs often act to slam the door into the closed position after the door has passed a particular rotational position when moved upward toward the closed position. This slamming is undesirable for at least the reasons that it can make a loud noise, it can damage the appliance over time, and it gives the appearance of low quality. The result of such slamming is usually that the user continues to hold the door unit it has reached the closed position.
To prevent the undesirable slamming, soft-close hinges can be employed. Soft-close hinges often include some type of damper that slows the movement of the door for a predetermined distance before the door reaches the closed position. This damping prevents the slamming of the door and results in a much more desirable appliance.
Some dampers include a spring mounted inside a cylinder. The spring is often very long compared to its diameter in order to fit inside the cylinder. The damper can include a rod that moves relative to the cylinder when the damper is operated. This movement can compress the spring, which can result in the spring moving in a direction perpendicular to the direction of compression. This lateral movement of the spring can result in the outside of the spring contacting the inside wall of the cylinder and/or the inside of the spring contacting the outside surface of the rod.
The invention recognizes that contact between the spring and the inside wall of the cylinder and/or the outside surface of the rod can cause noise and can reduce the life of the cylinder, the spring, and other components of the damper. To address the problem of the spring contacting the inside wall of the cylinder and/or the outside surface of the rod, the invention provides the spring with a low friction coating so that if the spring touches the inside wall of the cylinder and/or the outside surface of the rod little or no noise or wear results.
Particular embodiments of the invention are directed to a hinge assembly for pivotably attaching a door to a domestic appliance. The hinge assembly includes a hinge body configured to attach to the door such that the hinge body is fixed relative to the door; a damper cylinder attached to the hinge body and having an inside surface; a foot attached to the hinge body and the cylinder, the foot being configured to engage a foot receiving portion of the domestic appliance such that the hinge body and the door pivot relative to the domestic appliance; a rod partially located inside the cylinder and partially located outside the cylinder, the rod having an outer surface and being slidable relative to the cylinder in a reciprocating motion between a fully contracted position and a fully extended position; and a coil spring having an inner core and an outer coating, and positioned inside the cylinder and around the rod such that the rod extends through a center of a coil of the coil spring, the coil spring having an inner surface that is an inside surface of the coil of the coil spring, and an outer surface that is an outside surface of the coil of the coil spring.
Other embodiments of the invention are directed to a door assembly for pivotably attaching to a domestic appliance. The door assembly includes a door; and a hinge assembly. The hinge assembly includes a hinge body attached to the door such that the hinge body is fixed relative to the door; a damper cylinder attached to the hinge body and having an inside surface; a foot attached to the hinge body and the cylinder, the foot being configured to engage a foot receiving portion of the domestic appliance such that the hinge body and the door pivot relative to the domestic appliance; a rod partially located inside the cylinder and partially located outside the cylinder, the rod having an outer surface and being slidable relative to the cylinder in a reciprocating motion between a fully contracted position and a fully extended position; and a coil spring having an inner core and an outer coating, and positioned inside the cylinder and around the rod such that the rod extends through a center of a coil of the coil spring, the coil spring having an inner surface that is an inside surface of the coil of the coil spring, and an outer surface that is an outside surface of the coil of the coil spring.
Other embodiments of the invention are directed to a domestic appliance that includes a domestic appliance body having a foot receiving portion; a door; and a hinge assembly. The hinge assembly includes a hinge body attached to the door such that the hinge body is fixed relative to the door; a damper cylinder attached to the hinge body and having an inside surface; a foot attached to the hinge body and the cylinder, the foot engaging the foot receiving portion of the domestic appliance such that the hinge body and the door pivot relative to the domestic appliance; a rod partially located inside the cylinder and partially located outside the cylinder, the rod having an outer surface and being slidable relative to the cylinder in a reciprocating motion between a fully contracted position and a fully extended position; and a coil spring having an inner core and an outer coating, and positioned inside the cylinder and around the rod such that the rod extends through a center of a coil of the coil spring, the coil spring having an inner surface that is an inside surface of the coil of the coil spring, and an outer surface that is an outside surface of the coil of the coil spring.
The following figures form part of the present specification and are included to further demonstrate certain aspects of the disclosed features and functions, and should not be used to limit or define the disclosed features and functions. Consequently, a more complete understanding of the exemplary embodiments and further features and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, wherein:
The invention is described herein with reference to the accompanying drawings in which exemplary embodiments of the invention are shown. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.
Many domestic appliances, such as, for example, built-in ovens, have a door that pivots relative to the body of the appliance to permit access to an internal space of the appliance. These doors are often heavy due to glass view panels, insulation, ventilating structure, and other elements. Springs are often used to reduce the effort needed from the user to close the door. These springs can be strong in order to exert a force that counteracts a large portion of the weight of a heavy door. The result of strong springs is often a slamming of the door once the door passes a particular point in the pivoting.
One or more dampers can be used to damp the closing action resulting from the strong springs to eliminate the slamming that can be caused by undamped springs. The dampers can be any type of damper including, but not limited to, gas filled or liquid filled dampers. Examples of fluid (gas and/or liquid) filled dampers have a cylinder that contains the fluid and may or may not include one or more orifices through with the fluid moves to create the damping force.
Some door hinge assemblies include both a spring and a damper. Some of these door hinge assemblies place the spring inside the damper cylinder to provide a compact assembly.
Damper 200 includes a cylinder 300 and a rod 400. Rod 400 is partially inside cylinder 300 and partially outside cylinder 300 and moves in a reciprocating motion relative to cylinder 300. A damping force is applied to rod 400 as it moves relative to cylinder 300 and damps the motion of rod 400 relative to cylinder 300. This damping force can result from a fluid inside cylinder 300 being forced through at least one aperture when rod 400 moves, or from some other type of damping mechanism.
In this example, hinge assembly 100 is attached to door 30 such that hinge body 110 does not move relative to door 30. Also shown in
Embodiments of the invention include a coil spring positioned inside cylinder 300 as shown in
Applicants identified a solution to this problem by providing spring 500 with a coating that reduces the friction between spring 500 and rod 400 should the inside of spring 500 contact rod 400. The coating also reduces the friction between the outside of spring 500 and the inside of cylinder 300 should the outside of spring 500 contact the inside of cylinder 300.
Either one of these contact points (C, D) can cause the undesirable noise discussed above. This noise is at least in part caused by the metal-to-metal contact between spring 500 and cylinder 300 and/or between spring 500 and rod 400. Applicants discovered that this metal-to-metal contact and its associated noise can be eliminated by providing a coating on spring 500.
As shown in
Examples of appropriate non-metallic, low-friction, flexible coatings are some of the flouropolymer coatings such as Teflon® by DuPont™. The coating should be capable of withstanding the pressure that can result from the spring being pressed against the cylinder and/or the rod. The coating should also be capable of withstanding the heat that can result from the damper being exposed to the heat generated by the appliance (for example, an oven) and the heat generated by the damping fluid as a result of the damping function.
Applicants discovered that in some damper arrangements with internal springs the damping fluid can provide lubrication between the spring and the cylinder and/or between the spring and the rod. However, this arrangement is less desirable than the coating of the invention for at least the reason that the appliance door can remain in a closed position for a lengthy period of time which can result in the damping fluid leaving the surfaces of the cylinder and the rod. When the door is then opened, the spring can contact a surface of the cylinder or rod that is devoid of damping fluid, resulting in noisy and damaging metal-to-metal contact.
Although providing coating 540 adds to the cost of the damper unit, the noise reduction/elimination and the wear reduction/elimination outweigh the added cost. By reducing/eliminating the noise, the appliance presents a higher quality impression and by reducing/eliminating the wear, the appliance service life is extended.
In particular embodiments, spring 500 has a length to diameter ratio of between 1:15.7 and 1:14.7, preferably between 1:15.5 and 1:15.3.
It will be appreciated that variants of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the invention.
