This invention relates to a lift mechanism for a cleaning device of a dry shaving apparatus, with a base plate and a chassis arranged for displacement relative to the base plate, and a spring adapted to be secured in tension therebetween.
A cleaning device of this type is known from the appliance of the Braun company sold under the name “Clean & Charge”. This cleaning device includes a housing into which the dry shaving apparatus is inserted for cleaning purposes. This involves receiving the shaving head of the shaving apparatus in a receptacle designed as a cleaning bath. The housing further accommodates a reservoir containing a cleaning fluid. To clean the shaving head the cleaning fluid is fed from this reservoir into the receptacle. In the receptacle the cleaning fluid is caused to contact the shaving head in order to remove the hair dust collected in the shaving head. From the receptacle the cleaning fluid flows back into the reservoir, entraining with it the removed hair dust. The principle of operation of such a cleaning device is known, for example, from DE 44 02 237 C2. Considering that the effect of the cleaning fluid weakens with the number of cleaning processes increasing, it is necessary to substitute fresh cleaning fluid after a certain number of cleaning cycles. For this reason, the reservoir for the cleaning fluid is of the replaceable type. To replace the cleaning fluid reservoir, the housing of the cleaning device is opened by means of a lift mechanism, enabling the previous reservoir to be removed and a reservoir containing fresh cleaning fluid to be substituted. For this purpose, the cleaning device is divided into a base plate and a chassis.
The chassis is comprised of a chassis plate and the chassis proper. The base plate has guides for the spiral springs, said spiral springs being biased towards the chassis plate with the cleaning device in closed condition. Through a button provided on the outside of the housing the locked relationship between chassis and base plate is canceled and the lift mechanism is activated. The three spiral springs are untensioned and lift the chassis, thereby releasing the cleaning fluid reservoir for replacement. After the reservoir is replaced, the chassis is pushed down against the base plate, locking onto it at the same time. With the downward movement of the chassis the spiral springs are tensioned. Owing to the long opening travel of the housing it is necessary for the spiral springs to have a long spring excursion. At the same time the spiral springs have to hold the chassis securely in open condition. This necessitates relatively high forces for closing the housing and simultaneous tensioning the spiral springs. Moreover, these forces have a particularly strong effect also in closed condition because the spiral springs have a progressive spring characteristic. This puts a considerable strain on the structure of the cleaning device. Another disadvantage is the abrupt beginning and the abrupt end of the opening movement at a stop which is accompanied by loud noise. On account of the long spring excursion the spiral springs are guided. On actuation of the lift mechanism the spiral springs come into contact with the guides, which likewise leads to a not insubstantial noise level. The user of the cleaning device perceives such scraping noise as a disadvantage. Finally, the visible arrangement of the spiral springs adversely affects the appearance of the cleaning device.
It is therefore an object of the present invention to provide a cleaning device with a lift mechanism that operates as smoothly as possible, develops minimum possible noise while being of straight-forward construction, and puts little strain on the structure of the cleaning device.
According to the present invention this object is accomplished by providing the lift mechanism with at least one coiled-strip spring. The chassis is spring-loaded against the base plate by the coiled-strip spring. With the cleaning device in closed condition, the coiled-strip spring is uncoiled. Actuation of the lift mechanism releases the chassis, which is then moved by the relaxing coiled-strip spring coiling up in the process. The advantage of the coiled-strip spring made of strip steel is its nearly linear spring characteristic and its almost noiseless operation. In addition, owing to the coiling motion impact-type contact with other components or with itself is prevented from occurring during both coiling up and uncoiling, but rather, the chassis is lifted at largely constant speed through the entire stroke travel. The coiled-strip spring hence enables a substantially quieter lift mechanism. Moreover, the coiled-strip spring reduces the load on the chassis so that the construction has to withstand less severe stresses, strains and loads. Another advantage is that the provision of a suitable arrangement renders the coiled-strip spring, which coils up when the cleaning device is opened, invisible to the user. Therefore an additional surface treatment or encapsulation of the coiled-strip spring to enhance its appearance can be dispensed with.
Advantageously, the base plate has at least one guide that supports the movement of the chassis. Apart from one guide disposed centrally on the base plate, the arrangement of several guides on the circumference of the base plate may also be considered. Arranging the guides on the circumference has the advantage that sufficient space is available in the center of the base plate for the cleaning fluid reservoir and other built-in components. Canting of the chassis plate is avoided if guide bushings having a long guide length are provided on the chassis.
This guide may be constructed at the same time as a guide for one or several coiled-strip springs. The use of two coiled-strip springs for each guide, referred to as twin coiled-strip springs, has proven to be advantageous in this connection. The arrangement of two coiled-strip springs allows the use of small springs. The decisive advantage is, however, that it enables the symmetrical arrangement of the coiled-strip springs on a guide, which largely eliminates the risk of canting the chassis during the opening movement.
It has proven suitable to design two coiled-strip springs (twin coiled-strip springs) as a one-piece construction. In this design each end of a U-shaped length of strip steel is formed as a coiled-strip spring, with the two springs coiling up or uncoiling in outward direction. This enables both coiled-strip springs to be arranged on the guide with a single fastening. As a result, the number of single parts is reduced while at the same time the assembly is simplified. The coiled-strip springs may be fastened to the guide by frictional as well as positive engagement using, for example, screws, clips or rivets.
In another aspect the lift mechanism includes elements that slow down the movement of the chassis during opening of the cleaning device until the end position is reached. The decisive advantage of this configuration is that the opening movement is absolutely noiseless, since the chassis is prevented from striking hard against a stop limiting the opening movement. Furthermore, decelerating the lift mechanism has a wear-reducing effect.
The elements for the decelerated lift mechanism are elastic elements arranged either on the guide, the base plate or the chassis. The elastic elements may be spring, rubber, foam or other plastic parts which are moved against a stop. In this context, springs have proven to be advantageous because they allow slowing down of the lift mechanism through a relatively long travel. The stop may be arranged on the chassis as well as on the guides, preferably at the end remote from the base plate. Ease of assembly is accomplished by fastening the stop or the spring to the guide together with the coiled-strip spring. The use of spring clips has proven particularly suitable in this connection. These clips enable the fastening of the coiled-strip springs in addition to providing one or several springs for slowing down the opening movement of the chassis plate just before reaching the end position.
In another embodiment of the spring clips, the springs are bending springs cooperating each with a ramp disposed on the chassis. By suitably selecting the incline of the ramp a wide variety of different deceleration characteristics can be set. Thus a minor incline of the ramp results in a slow deceleration of the opening movement, whilst a major incline of the ramp produces a rapid deceleration. By varying the inclination over the distance to be covered it is possible to obtain combinations of the two decelerations. Thus it can be considered to provide the ramp initially with a small incline, which results in an only slow deceleration of the opening movement. As the chassis plate continues its approach to the end position, the ramp's incline increases, leading to a progressively increasing deceleration of the opening movement up to a complete stop. With suitable selection of the ramp design it is thus possible to set the end position in defined manner. In this instance no additional stop for the lift mechanism is necessary.
Further objects, features, advantages and application possibilities of the present invention will become apparent from the subsequent description of the embodiments. It will be understood that any single feature or any combination of single features described or represented by illustration form the subject-matter of the present invention, irrespective of their summary in the claims or their back-references.
An embodiment of the present invention will be described in the following. In the drawing,
The cleaning device 1 shown in
The lift mechanism shown in greater detail in
The open cleaning device 1 is shown in
As the chassis plate 8 is moved upwards, the ramp 27 strikes the cantilevered portion 13. In continuation of this movement, the cantilevered portion 13 is bent inwardly. The end 14 is also deflected inwardly until it meets the opposite end 14, urging it against the limit stop 28 of the guide bushing 9. On account of this elastic deformation of the spring clip 12 the upward movement of the lift mechanism is slowed down. With an appropriate design of the ramp and the spring clip 12 deceleration of the lift mechanism and the end position of the chassis plate 8 can be set arbitrarily within wide limits. Thus, it can be considered to design the limit stop 28 likewise as a ramp. In the present case the end position is produced by positive engagement when the shoulder 29 formed in the guide 9 meets the right-hand cantilevered portion 13 of the spring clip 12.
Number | Date | Country | Kind |
---|---|---|---|
102 10 351.8 | Mar 2002 | DE | national |
Number | Date | Country | |
---|---|---|---|
Parent | PCT/EP02/12887 | Nov 2002 | US |
Child | 10935828 | Sep 2004 | US |