CN211199920U

CN211199920U - Switch driving mechanism and switch

Info

Publication number: CN211199920U
Application number: CN201921258708.1U
Authority: CN
Inventors: 王南婷; 王长年; 龙剑飞; 张翔
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2019-07-31
Filing date: 2019-07-31
Publication date: 2020-08-07
Anticipated expiration: 2029-07-31

Abstract

The present disclosure relates to a turnout switch drive mechanism and a turnout switch, wherein the turnout switch drive mechanism comprises a switch drive device, a connecting rod and a connecting rod support, the switch drive device comprises a drive adapted to be fixed relative to a foundation and a push rod, the start end of the push rod is connected to the drive; the connecting rod is provided with a first end and a second end which are opposite, the connecting rod is arranged in line with the push rod, and the first end is connected with the tail end of the push rod so as to drive the push rod and the connecting rod to perform reciprocating translation along the transverse direction far away from and close to the driver through the driver; the connecting rod support is provided with: the connecting rod is used for connecting the connecting part of the second end of the connecting rod and limiting groove rails for limiting the position of the connecting rod relative to the connecting rod support. Through above-mentioned technical scheme, the turnout switch actuating mechanism that this disclosure provided can simplify the structure, reduce the installation degree of difficulty and reduce or even avoid the problem that structure itself brought.

Description

Switch driving mechanism and switch

Technical Field

The disclosure relates to the technical field of rail transit, in particular to a turnout switch driving mechanism and a turnout switch.

Background

A turnout is a line connection device for switching a rolling stock from one track to another track, and is usually laid in a large quantity at a station and a marshalling station so as to improve the passing capacity of a track line, and is an extremely important part and one of weak links in a railway.

In the related technology, the movement of the movable beam in the translation turnout can meet the requirement of switching the line of the train. The travelling beam is normally moved by means of a drive of a switch machine constructed with a rack and pinion transmission, which requires the aid of a trolley when connected to the travelling beam.

For the mechanism, on one hand, the structure is complex, a trolley is needed during installation, so that a large installation space is needed, and more parts need to be positioned in the installation process, so that accumulated installation errors are large during installation and positioning at multiple positions, the accurate installation position on site is inconvenient to adjust, and the universality is poor.

On the other hand, for the gear rack structure, the gear shaft of the driving part has the problems of high processing difficulty, high manufacturing cost and difficult guarantee of manufacturing precision, and the gear shaft is exposed for a long time, has short service life and high maintenance cost; in addition, the precision of the gear and rack meshing transmission is low, and the gear is easy to disengage during overtravel; and the tooth surface contact fatigue wear of the gear teeth of the gear shaft influences the smoothness of transmission and generates vibration and noise.

SUMMERY OF THE UTILITY MODEL

The purpose of this disclosure is to provide a switch driving mechanism, can simplify the structure, reduce the installation degree of difficulty and reduce or even avoid the problem that structure itself brought.

In order to achieve the above object, the present disclosure provides a switch point drive mechanism including:

a switch drive comprising a drive adapted to be fixed relative to a foundation and a push rod connected at its origin to said drive;

a link having opposite first and second ends, the link being arranged in line with the push rod and the first end being connected to a distal end of the push rod for driving the push rod and the link to translate reciprocally in a lateral direction away from and towards the driver by the driver; and the number of the first and second groups,

a connecting rod support provided with: the connecting rod is used for connecting the connecting part of the second end of the connecting rod, and the limiting groove rail is used for limiting the position of the connecting rod relative to the connecting rod support.

Optionally, the connecting rod support includes erection support and spacing support, the installation department including set up in erection support's first installation department with set up in spacing support's second installation department, erection support is provided with connecting portion, spacing support is provided with spacing grooved rail, this spacing grooved rail restriction the connecting rod with horizontal direction vertically longitudinal direction and vertical direction are relative the removal of connecting rod support.

Optionally, the limit support comprises a first fixed base plate provided with the second mounting portion and two oppositely arranged stop plates fixed on the first fixed base plate, the inner sides of the two stop plates opposite to each other are both provided with a groove extending along the transverse direction, the openings of the two grooves are oppositely arranged to configure the limit groove rail, and the connecting rod is accommodated in the two grooves.

Optionally, each inner side of the stop plate is connected with a limit block, and the groove is formed in the limit block.

Optionally, a reinforcing plate is further disposed on an outer side of each of the stop plates, and the reinforcing plate connects the stop plates and the first fixing substrate.

Optionally, the mounting support includes a second fixed substrate provided with the first mounting portion and a connection boss fixed on the second fixed substrate, and the connection portion is provided on the connection boss.

Optionally, the connecting rod is configured as a T-bar, and comprises a bar portion and a head portion, the second end corresponds to the head portion, the connecting portion is configured as a T-slot, and the second end of the T-bar is received in the T-slot.

Optionally, the connecting rod is configured as a T-shaped rod, comprising a rod portion and a head portion, the second end corresponding to the head portion, the connecting portion is configured as a cross-slot, and the second end of the T-shaped rod is received in the cross-slot.

Optionally, a position sensor for detecting a position of the connecting rod relative to the fixed beam is provided on the connecting rod.

Optionally, the connecting rod is connected with the push rod through a pin shaft, and the pin shaft extends in a direction perpendicular to the lower surface of the movable beam.

Optionally, the switch driving mechanism further comprises a push rod guide support, which is provided with a guide groove for guiding the push rod to move along the transverse direction.

Optionally, the push rod guide support is provided with a fixing portion for fixing relative to a fixing beam.

Optionally, the mounting portion includes a plurality of mounting holes, each of the mounting holes is correspondingly equipped with a fastener, and the fastener includes a spacer capable of adjusting the mounting height of the connecting rod support.

Optionally, the driver is configured as a motor, and the push rod is in transmission connection with an output of the motor through a lead screw transmission structure.

On the basis of the technical scheme, the disclosure also provides a turnout switch, wherein the turnout switch comprises the turnout switch driving mechanism.

Through above-mentioned technical scheme, the switch actuating mechanism of switch that this disclosure provided no longer connects the walking beam with the help of the platform truck, but adopts the mechanism of connecting rod and support, through on fixing the walking beam with the support promptly, the connecting rod is connected and is switched actuating device and support to realize through simple structure that the transmission between switch actuating device and the walking beam is connected, through the translation action of driver drive push rod, can realize the translation of walking beam and then realize the switch. When the mechanism is installed, on one hand, only the connecting rod support is needed to be installed on the movable beam, so that the accumulation of installation errors does not exist, and meanwhile, the installation space required by the connecting rod support is greatly reduced compared with that required by the trolley, so that the mechanism is convenient to flexibly arrange; on the other hand, the mechanism uses the connecting rod and the push rod to establish transmission connection with the movable beam, has simple structure, convenient processing and assembly, compact integral structure, small occupied space and low manufacturing and using cost, can change the design size of parts to realize different action strokes, and has good universality. The switch machine provided by the disclosure comprises the switch driving mechanism, so that the switch machine also has the advantages.

Additional features and advantages of the disclosure will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure without limiting the disclosure. In the drawings:

fig. 1 is a schematic perspective view of a turnout switch drive mechanism provided by an embodiment of the present disclosure;

FIG. 2 is a top view of the turnout switch drive mechanism provided by one embodiment of the present disclosure;

fig. 3 is a bottom view of the turnout switch drive mechanism provided in accordance with an embodiment of the present disclosure mounted on a moveable beam and a stationary beam.

Description of the reference numerals

11-a driver; 111-hand wheel; 12-a push rod; 2-a connecting rod; 21-a first end; 22-a second end; 3-limiting a support; 31-a first fixed substrate; 32-a stopper plate; 321-groove; 322-limit groove track; 33-a stopper 34-a reinforcing plate; 35-a second mounting portion; 4, mounting a support; 41-a second stationary substrate; 42-connecting the boss; 43-a first mounting portion; 421-a connecting portion; 5-a push rod guide support; 51-a guide groove; 52-a fixed part; 53-push rod guide support mounting holes; 6-a pin shaft; 7-a walking beam; 8-fixing the beam.

Detailed Description

The following detailed description of specific embodiments of the present disclosure is provided in connection with the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present disclosure, are given by way of illustration and explanation only, not limitation.

In the present disclosure, in the case where no description is made to the contrary, the direction toward the ground is defined as downward and the direction away from the ground is defined as upward, and the terms "first", "second", and the like are used for distinguishing one element from another element without order and importance. In addition, the use of directional terms such as "inner" and "outer" is intended to refer to the inner and outer relative to the profile of the corresponding component itself. Furthermore, in the following description, when referring to the figures, the same reference numbers in different figures denote the same or similar elements, unless otherwise explained. The foregoing definitions are provided to illustrate and describe the present disclosure only and should not be construed to limit the present disclosure.

According to an embodiment of the present disclosure, a switch drive mechanism is provided, one example of which is shown in fig. 1-3. Referring to fig. 1 and 2, the switch driving mechanism includes: a switch drive comprising a drive 11 adapted to be fixed with respect to the foundation and a push rod 12, the push rod 12 being connected at its beginning to said drive 11; a link 2 having opposite first and

second ends

21 and 22, said link 2 being arranged in line with said push rod 12, and said first end 21 being connected to a distal end of said push rod 12 for driving, by said driver 11, said push rod 12 and said link 2 in reciprocating translation in a transverse direction away from and towards said driver 11; and a connecting rod support provided with: a mounting portion for mounting on the lower surface of the walking beam 7, a connecting portion 421 for connecting the second end 22 of the link 2, and a limit groove rail 322 for limiting the position of the link 2 relative to the link support.

Through above-mentioned technical scheme, the switch driving mechanism that this disclosure provided no longer connects the walking beam 7 with the help of the platform truck, but adopts the mechanism of connecting rod 2 and support, through on fixing the walking beam 7 with the support promptly, connecting rod 2 connects switch drive arrangement and support to realize through simple structure that the transmission between switch drive arrangement and the walking beam 7 is connected, through the translation action of driver drive push rod 12, can realize the translation of walking beam 7 and then realize the switch. When the mechanism is installed, on one hand, only the connecting rod support needs to be installed on the movable beam 7, so that the accumulation of installation errors does not exist, and meanwhile, the installation space required by the connecting rod support is greatly reduced compared with that required by a trolley, so that the mechanism is convenient to flexibly arrange; on the other hand, the mechanism uses the connecting rod and the push rod to establish transmission connection with the movable beam 7, has simple structure, convenient processing and assembly, compact integral structure, small occupied space and low manufacturing and using cost, can change the design size of parts to realize different action strokes, and has good universality. In addition, the switch machine provided by the disclosure comprises the switch driving mechanism, so that the switch machine also has the advantages.

In the switch drive mechanism provided in the present disclosure, the above-mentioned link holders may be arranged and configured in any suitable manner, for example, the connection and the limit for the link in the link holder may be arranged on the same holder, that is: the connecting rod support may be configured with a connecting portion at one end, i.e. for connecting with a connecting rod, and a limiting groove rail at the other end, i.e. for limiting the connecting rod.

Or what also can be, be used for the connection of connecting rod and spacing separately setting in the connecting rod support to two supports are constructed correspondingly, can reduce the requirement to installation space, simultaneously, when the installation, can select the erection support and the spacing support of different grade type according to the demand of difference, and the selection space is bigger more nimble in the use. In addition, the error accumulation caused by the installation of the two supports does not relatively influence the overall installation precision. Alternatively, referring to fig. 1, the connecting rod support includes a mounting support 4 and a limiting support 3, the mounting portion includes a first mounting portion 43 disposed on the mounting support 4 and a second mounting portion 35 disposed on the limiting support 3, the mounting support 4 is provided with the connecting portion 421, the limiting support 3 is provided with a limiting groove rail 322, and the limiting groove rail 322 limits the movement of the connecting rod 2 relative to the connecting rod support in a longitudinal direction and a vertical direction perpendicular to the transverse direction. Specifically, the second end 22 of the connecting rod 2 is connected to a connecting portion 421 disposed on the mounting support 4, and the limiting groove rail 322 disposed on the limiting support 3 limits the connecting rod 2 to run on its track without derailing, so as to realize the reciprocating translational motion of the connecting rod 2 in the transverse direction away from and close to the driver 11 under the driving of the driver 11, and further drive the movable beam 7 to reciprocate translational motion.

The limit support 3 may have a plurality of structural manners, and the connecting rod 2 does not separate from the running track thereof when performing the reciprocating translational motion, alternatively, as shown in fig. 1, the limit support 3 includes a first fixed base plate 31 provided with the second mounting portion 35 and two oppositely disposed stop plates 32 fixed on the first fixed base plate 31, the inner sides of the two stop plates 32 opposite to each other are both provided with grooves 321 extending along the transverse direction, the openings of the two grooves 321 are oppositely disposed to configure as the limit groove rails 322, and the connecting rod 2 is accommodated in the two grooves 321. Simple structure, simple to operate realizes easily.

In the specific embodiment provided by the present disclosure, the limiting support 3 may further be provided with a through hole structure for the connecting rod 2 to pass through in a clearance fit manner, or may be provided with a sliding groove structure for the connecting rod 2 to slide.

In the specific embodiment provided by the present disclosure, the groove 321 may be disposed in any suitable manner, and optionally, as shown in fig. 1 and 2, a stopper 33 is connected to an inner side of each stopper plate 32, and the groove 321 is disposed on the stopper 33. Simple and compact structure and convenient assembly.

The above-mentioned limit block 33 and the groove 321 provided by the present disclosure may have various configurations, for example, the limit block 33 and the connecting rod 2 may be configured as follows: one of the two is circumferentially configured with a protrusion, and the other of the two is circumferentially configured with a groove structure matching the protrusion. The above-mentioned stopper 33 and the connecting rod 2 can also be constructed as follows: one of the two is provided with a roller, and the other one of the two is provided with a matching mode of a sliding groove matched with the roller.

In the embodiments provided in the present disclosure, in order to facilitate the processing and assembling, enhance the connection strength and rigidity, and improve the reliability, optionally, referring to fig. 1 and 2, a reinforcing plate 34 is further provided on an outer side of each of the stopper plates 32, and the reinforcing plate 34 connects the stopper plate 32 and the first fixing substrate 31. In the present disclosure, the reinforcing plate 34 may be arranged and configured in any suitable manner, and the stopper plate 32 and the first fixing base plate 31 may be connected in a reinforcing manner, and the reinforcing plate 34 may be provided in plurality, and the plurality of reinforcing plates 34 may be arranged at intervals along the reciprocating direction of the connecting rod 2. The reinforcing plate 34 may also be constructed as a trapezoidal structure parallel to the running direction of the connecting rod 2.

In the specific embodiment provided by the present disclosure, the mounting bracket 4 may have various configurations, and it is sufficient that the connecting rod 2 and the movable beam 7 can be fixedly connected, and alternatively, referring to fig. 1, the mounting bracket 4 includes a second fixed base plate 41 provided with the first mounting portion 43 and a connecting boss 42 fixed on the second fixed base plate 41, and the connecting portion 421 is provided on the connecting boss 42. Simple structure, simple to operate realizes easily, and the commonality is strong. In the present disclosure, the mounting seat 4 may be further configured such that a connecting portion matching with the connecting rod 2 is integrally formed on the movable beam 7, and the two are connected in an interference fit manner or detachably connected.

In the specific embodiment provided by the present disclosure, the connecting rod 2 has various configurations, and one end of the connecting rod can be fixedly connected with the mounting support 4, and the other end of the connecting rod can be connected with the tail end of the push rod 12 and can be consistent with the reciprocating motion of the push rod 12. Alternatively, referring to fig. 1 and 2, the link 2 is configured as a T-shaped bar including a bar portion and a head portion, the second end 22 corresponding to the head portion, and the connecting portion 421 is configured as a T-shaped groove in which the second end 22 of the T-shaped bar is received. The assembly is convenient, the connection is tight, the action area of the connecting rod 2 force of the T-shaped structure is large, the action force is more uniform, the stress concentration phenomenon is avoided, and the efficiency is improved.

In the embodiments provided in the present disclosure, for the convenience of assembly and the fastening of the connection, the connection portion 421 may have various configurations, and alternatively, referring to fig. 1 and 2, the connection rod 2 is configured as a T-shaped rod including a rod portion and a head portion, the second end 22 corresponds to the head portion, the connection portion 421 is configured as a cross-shaped groove, and the second end 22 of the T-shaped rod is received in the cross-shaped groove. The connecting portion 421 is constructed as a cross groove, the cross groove is convenient to assemble with the T-shaped head of the connecting rod 2, the connecting portion can be installed from any one side of two assembling ends of the cross groove, the mounting mode is flexible, the assembling is convenient, the connection is tight, the practicability is high, meanwhile, the action area of the connecting rod 2 of the T-shaped structure is large, the action force is more uniform, and the stress concentration phenomenon can be avoided.

In the specific embodiment provided by the present disclosure, a position sensor for detecting the position of the connecting rod 2 relative to the fixed beam 8 is optionally provided on the connecting rod 2. The position sensor has the advantages of convenient detection, high precision and easy realization, and can avoid the displacement caused by overlarge or undersize displacement of the movable beam 7 driven by the connecting rod 2 from being not in place, thereby improving the switch passing capacity of the track.

In the specific embodiment provided by the present disclosure, the connecting rod 2 and the push rod 12 may be arranged in any suitable manner, alternatively, referring to fig. 1 and 2, the connecting rod 2 is connected with the push rod 12 by a pin 6, and the pin 6 extends in a direction perpendicular to the lower surface. Can compensate assembly error, simple to operate conveniently changes the loss piece simultaneously, reduce cost improves circulation life.

Wherein, connecting rod 2 and push rod 12 can also be established through the cover and be connected, threaded connection, and the tip of push rod 12 can be equipped with the joint that is used for connecting, and the joint can have the through-hole, and connecting rod 2 can have the screw thread section, and the screw thread section through-hole of joint of connecting rod 2 to through lock nut lock die realization connection.

In the embodiment provided by the present disclosure, in order to reduce the loss of driving force, stabilize the operation and improve the switching accuracy, optionally, referring to fig. 1 and 2, the switch driving mechanism further includes a push rod guide support 5, and the push rod guide support 5 is provided with a guide groove 51 for guiding the push rod 12 to move in the transverse direction. The guide support 5 has various configurations, and the guide groove 51 on the guide support 5 can be arranged in any suitable manner, and can be matched with the push rod 12 in structure.

Wherein optionally the push rod guide support 5 is provided with a fixing portion 52 for fixing relative to the fixing beam 8. The bottom circumference of the fixing part 52 is provided with a plurality of push rod guide support mounting holes 53, the push rod guide support mounting holes 53 facilitate the fixation of the push rod guide support 5 and the fixing beam 8, and the fixing part is convenient to assemble, easy to replace and easy to realize.

In the specific embodiment provided by the present disclosure, the mounting portion may be connected with the movable beam 7 in any suitable manner, and alternatively, as shown in fig. 2 and 3, the mounting portion includes a plurality of mounting holes, each of which is correspondingly equipped with a fastener, and the fastener includes a connecting member such as a bolt and a gasket capable of adjusting the mounting height of the connecting rod support. Foretell first installation department 43 and second installation department 35 can have a plurality of such mounting holes respectively, and the fixed connection of support 4, spacing support 3 and walking beam 7 is conveniently dismantled, conveniently assembles and changes impaired piece. The gasket is convenient for adjusting the mounting heights of the mounting support 4 and the limiting support 3, so that the connecting rod 2 and the push rod 12 are arranged in a collinear manner.

In addition, the mounting portion may also mount the link bracket on the lower surface of the movable beam 7 by welding or screwing a fastener through a mounting hole.

In the embodiment provided by the present disclosure, in order to improve the control accuracy and thus the switching accuracy, optionally, the actuator 11 is configured as a motor, and the push rod 12 is in transmission connection with an output of the motor through a lead screw transmission structure. The above-mentioned actuators 11 may be arranged and constructed in any suitable manner, for example, the actuators 11 may be hydraulic cylinders, and the actuators 11 may also be pneumatic cylinders.

The preferred embodiments of the present disclosure are described in detail with reference to the accompanying drawings, however, the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present disclosure within the technical idea of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. In order to avoid unnecessary repetition, various possible combinations will not be separately described in this disclosure.

In addition, any combination of various embodiments of the present disclosure may be made, and the same should be considered as the disclosure of the present disclosure, as long as it does not depart from the spirit of the present disclosure.

Claims

1. A switch drive mechanism, comprising:

a switch drive comprising a drive (11) adapted to be fixed relative to the foundation and a push rod (12), the start of the push rod (12) being connected to the drive (11);

a connecting rod (2), the connecting rod (2) having a first end (21) and a second end (22) which are opposite, the connecting rod (2) is arranged in line with the push rod (12), and the first end (21) is connected with the tail end of the push rod (12) so as to drive the push rod (12) and the connecting rod (2) to perform reciprocating translation along the transverse direction far away from and close to the driver (11) through the driver (11); and the number of the first and second groups,

a connecting rod support provided with: the connecting device comprises a mounting part for mounting on the lower surface of the movable beam (7), a connecting part (421) for connecting the second end (22) of the connecting rod (2), and a limiting groove rail (322) for limiting the position of the connecting rod (2) relative to the connecting rod support.

2. The switch drive of claim 1, characterized in that the connecting rod support comprises a mounting support (4) and a limit support (3), the mounting portion comprises a first mounting portion (43) provided to the mounting support (4) and a second mounting portion (35) provided to the limit support (3), the mounting support (4) is provided with the connecting portion (421), the limit support (3) is provided with the limit groove rail (322), and the limit groove rail (322) limits the movement of the connecting rod (2) relative to the connecting rod support in the longitudinal direction and the vertical direction perpendicular to the transverse direction.

3. The switch drive according to claim 2, characterized in that the limit bracket (3) comprises a first fixed base plate (31) provided with the second mounting portion (35) and two oppositely arranged stop plates (32) fixed on the first fixed base plate (31), the two stop plates (32) are provided with grooves (321) extending in the transverse direction on the inner sides opposite to each other, the openings of the two grooves (321) are oppositely arranged to configure the limit groove rails (322), and the connecting rod (2) is accommodated in the two grooves (321).

4. The switch drive according to claim 3, characterized in that a stop block (33) is connected to the inner side of each stop plate (32), the groove (321) being provided on the stop block (33).

5. The switch drive according to claim 4, characterized in that a reinforcement plate (34) is further provided on the outer side of each stop plate (32), the reinforcement plate (34) connecting the stop plate (32) and the first fixed base plate (31).

6. The switch drive mechanism of claim 2, wherein the mounting bracket (4) comprises a second fixed base plate (41) provided with the first mounting portion (43) and a connecting boss (42) fixed to the second fixed base plate (41), and the connecting portion (421) is provided on the connecting boss (42).

7. The switch drive according to any of claims 1-6, characterized in that the connecting rod (2) is configured as a T-bar comprising a rod portion and a head portion, the second end (22) corresponding to the head portion, the connecting portion (421) being configured as a T-slot, the second end (22) of the T-bar being received in the T-slot.

8. The switch drive according to any of claims 1-6, characterized in that the connecting rod (2) is configured as a T-bar comprising a rod portion and a head portion, the second end (22) corresponding to the head portion, the connecting portion (421) being configured as a cross slot in which the second end (22) of the T-bar is received.

9. The switch drive of claim 1, characterized in that the connecting rod (2) is provided with a position sensor for detecting the position of the connecting rod (2) relative to the fixed beam (8).

10. The switch drive of claim 1, characterized in that the connecting rod (2) is connected to a push rod (12) by a pin (6), the pin (6) extending in a direction perpendicular to the lower surface of the movable beam (7).

11. The switch drive mechanism according to claim 1, characterized in that it further comprises a push rod guide support (5), which push rod guide support (5) is provided with a guide groove (51) for guiding the push rod (12) to move in the transverse direction.

12. Switch drive mechanism as claimed in claim 11, characterized in that the push rod guide support (5) is provided with a fixing portion (52) for fixing with respect to a fixed beam (8).

13. The switch drive mechanism as claimed in claim 1, wherein the mounting portion includes a plurality of mounting holes each correspondingly equipped with a fastener including a spacer capable of adjusting the mounting height of the connecting rod support.

14. The switch drive according to claim 1, characterized in that the actuator (11) is configured as an electric motor, the push rod (12) being in drive connection with the output of the electric motor via a spindle drive.

15. A switch machine comprising a switch drive mechanism as claimed in any one of claims 1 to 14.