Electricity: electrical systems and devices – Housing or mounting assemblies with diverse electrical... – For electronic systems and devices
Reexamination Certificate
2002-02-14
2003-05-13
Chervinsky, Boris (Department: 2835)
Electricity: electrical systems and devices
Housing or mounting assemblies with diverse electrical...
For electronic systems and devices
C361S628000, C361S643000, C361S652000, C361S656000, C361S657000, C361S658000, C200S293000
Reexamination Certificate
active
06563707
ABSTRACT:
TECHNICAL FIELD
The invention relates to a chassis for mounting component units in an electric switch cabinet for elevators and escalators.
BACKGROUND ART
For control of electric elevators and escalators, there are required electric control means that are usually accommodated in control or switch cabinets installed in a machine room or hoistway in a building or in an escalator or moving steps. Such switch cabinets conventionally have a sheet metal housing having attached thereto component units, for example, circuit boards, relays, capacitors, transformers etc., by means of frame parts, screws, spacer bolts, brackets etc. One thus arrives at a large amount of parts. It is quite cost-intensive and time-consuming to manufacture all necessary parts, to mount and assemble them and to disassemble them again for maintenance, repair or recycling purposes.
DE 36 12 511 A discloses a distribution cabinet comprising a housing and a component carrier inserted in the housing. The housing comprises a rigid frame consisting of square metal sections and having vertical supports and horizontal rails as well as struts extending along the housing edges. A bottom part, a cover part and side parts of the housing are formed by shaped parts of rigid expanded plastics material and are provided with mounting blocks for mounting the apparatus carrier and with reinforcing ribs. The component carrier has rails for attachment of electrical instruments and equipment. Such a distribution cabinet consists of a plurality of individual components that have to be connected to each other by connecting members and is relatively heavy.
For heavyweight components, such as e.g. transformers or filters, there is a particularly high risk of damage, for instance in the form of broken bolts, screws, anchorages, etc., as a result of vibrations or shocks during transport. Switch cabinets for elevators and escalators furthermore contain noise generating components, such as power switches and relays. Thus, sound-absorbing materials must additionally be accommodated in such a switch cabinet.
It is known from U.S. Pat. No. 5,644,472 A to reduce the assembly cost for desktop computers by inserting individual components of such a computer, such as the main board along with the processor, the fixed disk and the fan, into recesses matched to the shape thereof which are formed in a carrier of foamed urethane material composed of an upper carrier part and a lower carrier part, to thereby maintain the components in their desired positions. Although these components are first held in positive or form-locking manner by the foamed urethane material, it may happen due to vibrations or shocks during transport or during operation of such a desktop computer that the receiving recesses for the individual components are undesirably increased since the foamed urethane material does not have a sufficient resetting force with respect to compression forces, so that deformations of the receiving recesses as a result of vibration and/or shock forces are permanent. This may be counteracted according to the reference, by attaching some or all of the components accommodated in the carrier to the carrier by means of fastening elements such as screws, brackets etc. However, this in turn causes a corresponding increase in manufacturing and mounting cost.
It is known from DE 91 16 755 U1 and the corresponding U.S. Pat. No. 5,473,507 A to make such a carrier for a computer or a measuring apparatus of expanded polypropylene (EPP), a material with high stability in shape and elastic resetting force with respect to compression. Individual components of the computer, such as in particular a fan, a fixed disc, a main board, a loudspeaker and capacitors, are each inserted in a receiving cavity of the carrier that is closely matched to the outer shape of the particular component. Due to the high resetting force of the plastics material used and the snug fit of the individual components, the components are permanently retained in their position. There are thus no additional fastening elements provided, so that an overall reduction in manufacturing and mounting cost is obtained.
However, such carriers are designed for receipt of comparatively light-weight computer components which remain identical in their outer shape for various computer models, and are not suited without further ado as carriers for elevator and escalator switch cabinets that must carry components or components units that are not only relatively heavy in part, but which in part may also have quite different shapes and/or may be provided in different numbers, depending on the particular model and intended application of the particular switch cabinet. If the conception of the above-mentioned carriers were used for computers for elevator and escalator switch cabinets, a matched shaped plastics part of its own would have to be produced for each switch cabinet model, which would require a corresponding number of injection molds. In the light of the comparatively low number of pieces per switch cabinet model for escalators and elevators, as compared with mass-produced apparatus like computers, this would constitute an unbearable cost expenditure.
DISCLOSURE OF INVENTION
It is the object of the invention to make available a chassis of the type indicated at the outset, through which the manufacturing and mounting costs for elevator and escalator switch cabinets can be reduced by making use of the afore-mentioned conception for carriers of computer components, while simultaneously reducing the possibility of damages, and improving both noise attenuation as well as usability for various switch cabinet models.
A chassis of the type according to the invention comprises a shaped part (molded part) serving as main supporting member, which is composed with a plastics material with lasting resetting force with respect to compression and is provided with at least one receiving recess for receiving a component unit of a first type in substantially positive snug fitting or form-locking manner. In addition thereto, a chassis of the type according to the invention is provided with at least one mounting rail serving as auxiliary supporting member and anchored in the shaped part, said mounting rail, at least over a predetermined partial length thereof, being accessible in a free space of the shaped part for mounting at least one component unit of a second type to said mounting rail, with said free space being designed and dimensioned such that such component units of the second type can be received in different numbers, shapes and sizes.
In an embodiment of the invention, the shaped part consists of expanded polypropylene (EPP). However, any other plastics material with stability in shape and sufficient lasting resetting force as regards compression may be used as well. Alternative materials are, for instance, polyurethane and polyethylene. Plastics materials are preferred that can be injection-molded in an injection mold also as larger shaped parts.
Each of the component units of a first type has associated therewith a receiving recess of its own of the chassis, which is closely matched to the outer shape of the respective component unit and receives this component unit to a predetermined insertion depth. Preferably, the respective receiving recess is dimensioned such that the associated component unit is received therein in a press fit. Due to the high resetting force of the plastics material used, a holding force is exerted on the respective component unit such that it is permanently held in its position. The component units of the first type merely need to be inserted in the receiving recesses provided therefor, so that an overall reduction of the manufacturing and mounting expenditure is obtained. For such component units, in the event they are too heavy to be still safely held in their receiving recesses by the resetting force of the plastics material of the shaped part also in case of tipping of the chassis, there may be provided additional fastening elements for safely fixing such component units.
Due to the
Belkner Andreas O.
Dehmlow Marvin
Engler Hartmut
Schoppa Wolfgang
Steifa Vera Else Marta
Chervinsky Boris
Otis Elevator Company
LandOfFree
Chassis for mounting component units of an electric switch... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Chassis for mounting component units of an electric switch..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Chassis for mounting component units of an electric switch... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3047201