The present invention relates to a railroad toggle switch according to the preamble of claim 1. The railroad toggle switch is conceived for a plurality of switching positions and comprises a housing, an operating lever supported on the housing and having a pivot axis, a switching cylinder supported on the housing and having a rotational axis, a plurality of microswitches and an engaging mechanism for engagement of the operating lever in the switching positions. The switching cylinder normally includes a plurality of cam disks for operating the microswitches.
Such a railroad toggle switch has been known from the prior art since a long time and is used in the control panels of trains, subways, etc. In these railroad toggle switches known from the prior art, the operating lever is made integral with the switching cylinder or is firmly connected thereto. The pivot axis of the operating lever is thus coincident with the rotational axis of the switching cylinder. The outer dimensions of the railroad toggle switch are mostly standardized by the train manufacturers, whereby exchangeability in the control panels is to be ensured.
As a result of the standardization of the outer dimensions of the railroad toggle switches, both the number of the microswitches that can be operated by the switching cylinder and the possible switching positions are limited. In the construction of a railroad toggle switch known from the prior art, the microswitches are arranged at the side of the switching cylinder that is opposite the operating lever, i.e. underneath the switching cylinder. A schematic illustration of a railroad toggle switch known from the prior art is shown in
Moreover, DE 741078 reveals a cord switch for operating a heating pad. The cord switch comprises a housing, a switching drum, and an operating lever. Terminals arranged on the housing are connected, depending on the switching position, directly by the switching drum or by a conductor extending through the switching drum. To ensure the necessary switching capacity in the case of several switching positions, a transmission device is provided between the operating lever and the switching drum, by which device the rotational angles of the operating lever become smaller than the rotational angles of the switching drum. The switch is not designed for operating microswitches. The housing opening required for operating the operating lever is very large and does not provide adequate protection against splash water.
Since in modern trains more and more devices and functions are served from the control panel, there is a demand for toggle switches by which additional switching positions and the operation of additional microswitches are realized with the same outer dimensions of the railroad toggle switches. Moreover, the demand for additionally operable microswitches is already justified by the fact that in modern transportation systems not only the corresponding device or the desired function has now to be activated by operating a toggle switch, but an information signal must also be sent to the on-board computer by simultaneously operating an additional microswitch. It is therefore the object of the present invention to provide a railroad toggle switch by which, on the one hand, more microswitches can be operated than with the railroad toggle switches known from the prior art and by which, on the other hand, more switching positions can be implemented. Moreover, the further drawbacks of the railroad toggle switches known from the prior art shall be overcome.
The object is achieved with the features of claim 1. Thus an inventive solution for the object is achieved if the pivot axis of the operating lever is located in the area of the housing top side and differs from the rotational axis of the switching cylinder. Furthermore the operating lever is in engagement with the switching cylinder. The arrangement according to the invention yields considerable advantages. Owing to the arrangement of the rotational axis of the switching cylinder in a way independent of the pivot axis of the operating lever it is possible to provide the necessary space for arranging more microswitches around the switching cylinder. Owing to the arrangement of the pivot axis of the operating lever in the area of the housing top side the housing opening needed for the operating lever can be kept small in size, resulting in improved protection against splash water. Since the operating lever is not firmly connected to the switching cylinder, but is in engagement with said cylinder it is possible to implement an appropriate transmission ratio between operating lever and switching cylinder. It is thereby possible to obtain the rotational angles of the switching cylinder needed for the switching operation at relatively small pivot angles of the operating lever.
Further developments of the present invention are the subject matter of the subclaims.
In a preferred embodiment, operating lever and switching cylinder are in engagement via gear segments. To this end a first gear segment is connected to the operating lever and a second gear segment is connected to the switching cylinder. It is thereby possible to establish a gear ratio between operating lever and switching cylinder. For instance if small pivot angles of the operating lever are desired for the operation, the necessary rotational angles of the switching cylinder can be achieved through a corresponding gear ratio. As an alternative, engagement and transmission can also be accomplished by way of a sliding joint.
In a further preferred embodiment the cam disks are arranged to be individually exchangeable on the switching cylinder. If some or all microswitches are arranged at a different place of the switching cylinder or also more microswitches are positioned around the switching cylinder, there is no need for exchanging the whole switching cylinder. It is enough when the corresponding cam disks are adapted or rotated on the switching cylinder relative to the remaining cam disks. An adaptation can also be made when a microswitch is to be operated in a switching position differing from the original one.
Preferably, the second gear segment connected to the switching cylinder is configured as part of one of the cam disks. To this end gear segment and cam disk can be made in once piece.
In a further preferred embodiment the gear rim of one of the two gear segments is laterally completed by walls. The walls extend in radial extension up to the tips of the teeth. It can thereby be prevented that the gear segments are displaced laterally relative to one another. It is thereby ensured that the gear segments are always in perfectly meshing engagement with one another.
In a further preferred embodiment the engaging mechanism comprises at least one notch element that is connected to the operating lever and has one notch per switching position and one locking cam per notch element. The locking cam is arranged on a lever arm which is spring-supported on the housing and engages in one switching position into the notch of the notch element corresponding to the switching position.
Preferably, the engaging mechanism comprises two notch elements, the two notch elements being arranged in symmetry at both sides of the first gear segment and connected to the first gear segment. A respective locking cam is provided as a counter piece for each notch element. Both locking cams are jointly arranged on the spring-supported lever arm. Thanks to the symmetric arrangement, any one-sided load on the mechanism and thus any jamming is prevented and ease of operation of the railroad toggle switch is ensured.
Preferably, the locking cams are not firmly connected to the lever arm, but are configured as a roller that is rotatably supported on the lever arm. Upon operation of the railroad toggle switch the rollers are rolling on the associated notch elements, whereby the ease of operation of the railroad toggle switch is further enhanced.
In a further preferred embodiment, the microswitches are arranged laterally next to the switching cylinder at one side of the switching cylinder. Thanks to the lateral arrangement the microswitches are protected in an improved way against splash water in comparison with an arrangement underneath the switching cylinder.
In case more microswitches are to be operated than can be arranged at one side of the switching cylinder, the microswitches are preferably arranged at both sides of the switching cylinder. It is here also possible to safely protect the microswitches against splash water which may possibly enter because of the housing opening needed for the operating lever.
If more microswitches are to be operated than can be accommodated at both sides of the switching cylinder, the microswitches are preferably arranged at both sides of the switching cylinder and underneath the switching cylinder. The cam disks must be adapted accordingly for this purpose.
The microswitches are preferably pre-mounted on carrier plates. Terminals may also be provided on said carrier plates, the terminals enabling ease of wiring of the railroad toggle switch. The housing preferably comprises accommodating means at both sides of the switching cylinder for fastening the carrier plates.
In a further preferred embodiment the operating lever is supported on the housing in a bearing, the bearing being configured as a ball-and-socket joint. Thanks to the ball-and-socket joint the seal protection against splash water is improved considerably. The operating lever is here freely movable in principle, so that the pivot axis of the operating lever is just an imaginary pivot axis. The ball of the ball-and-socket joint is part of the operating lever; the socket of the ball-and-socket joint is formed by a part of the housing.
Preferably, the ball-and-socket joint comprises a sealing ring. The sealing ring can be inserted into a groove of either the ball or the socket of the ball-and-socket joint and is normally made of rubber or a swelling felt material. Enhanced ease of use is achieved with a felt material.
Since the operating lever is in principle freely movable by way of the ball-and-socket joint, the housing in the area of the bearing preferably comprises guide surfaces for guiding the operating lever. Thanks to these guide surfaces the pivoting direction is clearly defined and the pivot axis of the operating lever is re-established.
A preferred embodiment shall now be explained in more detail with reference to drawings, in which:
As for the whole further description, if reference numerals are included in a figure for the sake of graphical clarity, but if these are not explained in the associated text of the description, reference will be made to their explanation given in preceding descriptions of the figures.
Number | Date | Country | Kind |
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10 2008 057 148.2 | Nov 2008 | DE | national |