Safety switch and control system for vehicles

Claim 2

An electrical switch operable by a change in the force transmitted between first and second control elements, comprising first and second movable members having means for connecting said movable members to the respective first and second control elements, said first and second movable members being movable with said first and second control elements, said first and second movable members having means interconnecting said members for relative movement between first and second positions, the transmission of force between said control elements being effective to cause relative movement of said first and second movable members to said first position, resilient means acting between said first and second movable members and biasing said members for relative movement to said second position, and switching means operable between two different switching states in response to relative movement of said members between said first and second positions, whereby one of said switching states is produced by normal Transmission of force between said control elements, while the other switching state is produced in the absence of such transmission of force, said switching means comprising movable contact means mounted on one of said movable members and movable therewith, stationary contact means alongside the path of movement of said movable contact means and spaced laterally therefrom, and means operable by relative movement of said first and second movable members for moving said movable contact means laterally into and out of engagement with said stationary contact means.

Claim 3

A switch according to claim 1, in which said stationary contact means include a pair of stationary contact elements spaced laterally from said movable contact means, said movable contact means comprising a pair of movable contact elements movable laterally into and out of engagement with said stationary contact elements to form a conductive bridge therebetween.

Claim 4

An electrical switch operable by a change in the force transmitted between first and second control elements comprising, first and second movable members having means for connecting said movable members to the respective first and second control elements, said first and second movable members being movable with said first and second control elements, said first and second movable members having means interconnecting said members for relative movement between first and second positions, the transmission of force between said control elements being effective to cause relative movement of said first and second movable members to said first position, resilient means acting between said first and second movable members and biasing said members for relative movement to said second position, and switching means operable between two different switching states in response to relative movement of said members between said first and second positions, whereby one of said switching states is produced by normal transmission of force between said control elements, while the other switching state is produced in the absence of such transmission of force, said switching means comprising movable contact means mounted on one of said movable members and movable therewith, stationary contact means alongside the path of movement of said movable contact means, and means operable by relative movement of said first and second movable members for moving said movable contact means into and out of engagement with said stationary contact means, said last-mentioned means comprising a camming element movable with one of said movable members and engageable with said movable contact means.

Claim 5

An electrical switch operable by a change in the force transmitted between first and second control elements comprising, first and second movable members having means for connecting said movable members to the respective first and second control elements, said first and second movable members being movable with said first and second control elements, said first and second movable members having means interconnecting said members for relative movement between first and second positions, the transmission of force between said control elements being effective to cause relative movement of said first and second movable members to said first position, resilient means acting between said first and second movable members and biasing said members for relative movement to said second position, and switching means operable between two different switching states in response to relative movement of said members between said first and second positions, whereby one of said switching states is produced by normal transmission of force between said control elements, while the other switching state is produced in the absence of such transmission of force, said switching means comprising movable contact means mounted on one of said movable members and movable therewith, stationary contact means alongside the path of movement of said movable contact means, and means operable by relative movement of said first and second movable members for moving said movable contact means into and out of engagement with said stationary contact means, said last-mentioned means comprising a camming element movable with one of said movable members and engageable with said movable contact means.

Claim 6

An electrical switch operable by a change in the force transmitted between first and second control elements comprising, first and second movable members having means for connecting said movable members to the respective first and second control elements, said first and second movable members being movable with said first and second control elements, said first and second movable members having means interconnecting said members for relative movement between first and second positions, the transmission of force between said control elements being effective to cause relative movement of said first and second movable members to said first position, resilient means acting between said first and second movable members and biasing said members for relative movement of said second position, and switching means operable between two different switching states in response to relative movement of said members between said first and second positions, whereby one of said switching states is produced by normal transmission of force between said control elements, while the other switching state is produced in the absence of such transmission of force, said switching means comprising movable contact means mounted on one of said movable members and movable therewith, stAtionary contact means alongside the path of movement of said movable contact means, and means operable by relative movement of said first and second movable members for moving said movable contact means into and out of engagement with said stationary contact means, at least one of said contact means being elongated to provide for engagement between said movable and stationary contact means throughout the range of movement of said movable members.

Claim 7

An electrical switch operable by a change in the force transmitted between first and second control elements comprising, first and second movable members having means for connecting said movable members to the respective first and second control elements, said first and second movable members being movable with said first and second control elements, said first and second movable members having means interconnecting said members for relative movement between first and second positions, the transmission of force between said control elements being effective to cause relative movement of said first and second movable members to said first position, resilient means acting between said first and second movable members and biasing said members for relative movement of said second position, and switching means operable between two different switching states in response to relative movement of said members between said first and second positions, whereby one of said switching states is produced by normal transmission of force between said control elements, while the other switching state is produced in the absence of such transmission of force, said switching means comprising movable contact means mounted on one of said movable members and movable therewith, stAtionary contact means alongside the path of movement of said movable contact means, and means operable by relative movement of said first and second movable members for moving said movable contact means into and out of engagement with said stationary contact means, at least one of said contact means being elongated to provide for engagement between said movable and stationary contact means throughout the range of movement of said movable members.

Claim 8

An electrical switch operable by a change in the force transmitted between first and second control elements, comprising, first and second movable members having means for connecting said movable members to the respective first and second control elements, said first and second movable members being movable with said first and second control elements, said first and second movable members having means interconnecting said members for relative movement between first and second positions, the transmission of force between said control elements being effective to cause relative movement of said first and second movable members to said first position, resilient means acting between said first and second movable members and biasing said members for relative movement to said second position, and switching means operable between two different switching states in response to relative movement of said members between said first and second positions, whereby one of said switching states is produced by normal transmission of force between said control elements, while the other switching state is produced in the absence of such transmission of force, said switching means comprising a pair of movable contactors mounted on one of said movable members and movable therewith, a pair of stationary contact elements disposed along the paths of movement of said contactors, and means operable by relative movement of said first and second members for moving said contactors into and out of engagement with said contact elements.

Claim 9

An electrical switch operable by a change in the force transmitted between first and second control elements, comprising, first and second movable members having means for connecting said movable members to the respective first and second control elements, said first and second movable members being movable with said first and second control elements, said first and second movable members having means interconnecting said members for relative movement between first and second positions, the transmission of force between said control elements being effective to cause relative movement of said first and second movable members to said first position, resilient means acting between said first and second movable members and biasing said members for relative movement to said second position, and switching means operable between two different switching states in response to relative movement of said members between said first and second positions, whereby one of said switching states is produced by normal transmission of force between said control elements, while the other switching state is produced in the absence of such transmission of force, said switching means comprising a pair of movable contactors mounted on one of said movable members and movable therewith, a pair of stationary contact elements disposed along the paths of movement of said contactors, and means operable by relative movement of said first and second members for moving said contactors into and out of engagement with said contact elements.

Claim 10

An electrical switch according to claim 5, in which said last-mentioned means include camming means disposed on one of said movable members and engageable with said contactors.

Claim 11

An electrical switch according to claim 5, in which said stationary contact elements are elongated in the direction of movement of said movable members to provide for engagement between said contactors and said contact elements throughout the range of movement of said contactors.

Claim 12

An electrical switch according to claim 5, in which said contactors are in the form of contact arms swingably mounted on one of said movable members for outward movement into engagement with said stationary contact elements.

Claim 13

An electrical switch according to claim 5, in which said resilient means include an element biasing said contactors away from engagement with said contact elements.

Claim 14

An electrical switch operable by a change in the tension transmitted between first and second tension elements, comprising a casing, first and second movable members mounted in said casing for movement therein and having means for connecting said movable members to the respective first and second tension elements, said first and second movable members being movable with said first and second tension elements, said first and second movable members having means interconnecting said members for relative lost motion between first and second positions, the normal transmission of tension between said tension elements being effective to cause relative movement of said first and second movable members to said first position, resilient means acting between said first and second movable members and biasing said members for relative movement to said second position, and switching means operable between two different switching states in response to relative movement of said first and second movable members between said first and second positions, wherEby one of said switching states is produced by normal transmission of tension between said tension elements, while the other switching state is produced in the absence of such transmission of tension, said switching means comprising a movable contact element mounted on one of said movable members, a stationary contact element mounted on said casing opposite said movable contact element and spaced laterally therefrom, and means operable by relative movement between said first and second movable members for moving said movable contact element laterally into and out of engagement with said stationary contact element.

Claim 15

An electrical switch operable by a change in the tension transmitted between first and second tension elements, comprising a casing, first and second movable members mounted in said casing for movement therein and having means for connecting said movable members to the respective first and second tension elements, said first and second movable members being movable with said first and second tension elements, said first and second movable members having means interconnecting said members for relative lost motion between first and second positions, the normal transmission of tension between said tension elements being effective to cause relative movement of said first and second movable members to said first position, resilient means acting between said first and second movable members and biasing said members for relative movement to said second position, and switching means operable between two different switching states in response to relative movement of said first and second movable members between said first and second positions, wherEby one of said switching states is produced by normal transmission of tension between said tension elements, while the other switching state is produced in the absence of such transmission of tension, said switching means comprising a movable contact element mounted on one of said movable members, a stationary contact element mounted on said casing opposite said movable contact element and spaced laterally therefrom, and means operable by relative movement between said first and second movable members for moving said movable contact element laterally into and out of engagement with said stationary contact element.

Claim 16

A switch according to claim 10, including a second movable contact element mounted on said one of said movable members, and a second stationary contact element mounted on said casing opposite said second movable contact element and spaced laterally therefrom, said second movable contact element being movable laterally by said last-mentioned means into and out of engagement with said second stationary contact element, said movable contact elements being connected together to form a conductive bridge between said stationary contact elements.

Claim 17

An electrical switch operable by a change in the tension transmitted between first and second tension elements, comprising a casing, first and second movable members mounted in said casing for movement therein and having means for connecting said movable members to the respective first and second tension elements, said first and second movable members being movable with said first and second tension elements, said first and second movable members having means interconnecting said members for relative lost motion between first and second positions, the normal transmission of tension between said tension elements being effective to cause relative movement of said first and second movable members to said first position, resilient means acting between said first and second movable members and biasing said members for relative movement to said second position, and switching means operable between two different switching states in response to relative movement of said first and second movable members between said first and second positions, whereby one of said switching states is produced by normal transmission of tension between said tension elements, while the other switching state is produced in the absence of such transmission of tension, said switching means comprising a movable contact element mounted on one of said movable members, a stationary contact element mounted on said casing opposite said movable contact element, and means operable by relative movement between said first and second movable members for moving said movable contact element into and out of engagement with said stationary contact element, said last-mentioned means including a camming element operable by one of said movable members and engageable with said movable contact element.

Claim 18

An electrical switch operable by a change in the tension transmitted between first and second tension elements, comprising a casing, first and second movable members mounted in said casing for movement therein and having means for connecting said movable members to the respective first and second tension elements, said first and second movable members being movable with said first and second tension elements, said first and second movable members having means interconnecting said members for relative lost motion between first and second positions, the normal transmission of tension between said tension elements being effective to cause relative movement of said first and second movable members to said first position, resilient means acting between said first and second movable members and biasing said members for relative movement to said second position, and switching means operable between two different switching states in response to relative movement of said first and second movable members between said first and second positions, whereby one of said switching states is produced by normal transmission of tension between said tension elements, while the other switching state is produced in the absence of such transmission of tension, said switching means comprising a movable contact element mounted on one of said movable members, a stationary contact element mounted on said casing opposite said movable contact element, and means operable by relative movement between said first and second movable members for moving said movable contact element into and out of engagement with said stationary contact element, said last-mentioned means including a camming element operable by one of said movable members and engageable with said movable contact element.

Claim 19

An electrical switch operable by a change in the tension transmitted between first and second tension elements, comprising a casing, first and second movable members mounted in said casing for movement therein and having means for connecting said movable members to the respective first and second tension elements, said first and second movable members being movable with said first and second tension elements, said first and second movable members having means interconnecting said members for relative lost motion between first and second positions, the normal transmission of tension between said tension elements being effective to cause relative movement of said first and second movable members to said first position, resilient means acting between said first and second movable members and biasing said members for relative movement to said second position, and switching means operable between two different switching states in reSponse to relative movement of said first and second movable members between said first and second positions, whereby one of said switching states is produced by normal transmission of tension between said tension elements, while the other switching state is produced in the absence of such transmission of tension, said switching means comprising a movable contact element mounted on one of said movable members, a stationary contact element mounted on said casing opposite said movable contact element, and means operable by relative movement between said first and second movable members for moving said movable contact element into and out of engagement with said stationary contact element, one of said contact elements being elongated to provide for engagement between said movable and stationary contact elements along the path of movement of said first and second movable members.

Claim 20

An electrical switch operable by a change in the tension transmitted between first and second tension elements, comprising a casing, first and second movable members mounted in said casing for movement therein and having means for connecting said movable members to the respective first and second tension elements, said first and second movable members being movable with said first and second tension elements, said first and second movable members having means interconnecting said members for relative lost motion between first and second positions, the normal transmission of tension between said tension elements being effective to cause relative movement of said first and second movable members to said first position, resilient means acting between said first and second movable members and biasing said members for relative movement to said second position, and switching means operable between two different switching states in reSponse to relative movement of said first and second movable members between said first and second positions, whereby one of said switching states is produced by normal transmission of tension between said tension elements, while the other switching state is produced in the absence of such transmission of tension, said switching means comprising a movable contact element mounted on one of said movable members, a stationary contact element mounted on said casing opposite said movable contact element, and means operable by relative movement between said first and second movable members for moving said movable contact element into and out of engagement with said stationary contact element, one of said contact elements being elongated to provide for engagement between said movable and stationary contact elements along the path of movement of said first and second movable members.

Claim 21

An electrical switch operable by a change in the tension transmitted between first and second tension elements, comprising a casing, first and second movable members mounted in said casing for movement therein and having means for connecting said movable members to the respective first and second tension elements, said first and second movable members being movable with said first and second tension elements, said first and second movable members having means interconnecting said members for relative lost motion between first and second positions, the normal transmission of tension between said tension elements being effective to cause relative movement of said first and second movable members to said first position, resilient means acting between said first and second movable members and biasing said members for relative movement to said second position, and switching means operable between two different switching states in response to relative movement of said first and second movable members between said first and second positions, whereby one of said switching states is produced by normal transmission of tension between said tension elements, while the other switching state is produced in the absence of such transmission of tension, said switching means comprising a movable contact element mounted on one of said movable members, a stationary contact element mounted on said casing opposite said movable contact element, and means operable by relative movement between said first and second movable members for moving said movable contact element into and out of engagement with said stationary contact element, said stationary contact element being in the form of an elongated contact member mounted on said casing for engagement by said movable contact element throughout the range of movement of said movable members.

Claim 22

An electrical switch operable by a change in the tension transmitted between first and second tension elements, comprising a casing, first and second movable members mounted in said casing for movement therein and having means for connecting said movable members to the respective first and second tension elements, said first and second movable members being movable with said first and second tension elements, said first and second movable members having means interconnecting said members for relative lost motion between first and second positions, the normal transmission of tension between said tension elements being effective to cause relative movement of said first and second movable members to said first position, resilient means acting between said first and second movable members and biasing said members for relative movement to said second position, and switching means operable between two different switching states in response to relative movement of said first and second movable members between said first and second positions, whereby one of said switching states is produced by normal transmission of tension between said tension elements, while the other switching state is produced in the absence of such transmission of tension, said switching means comprising a movable contact element mounted on one of said movable members, a stationary contact element mounted on said casing opposite said movable contact element, and means operable by relative movement between said first and second movable members for moving said movable contact element into and out of engagement with said stationary contact element, said stationary contact element being in the form of an elongated contact member mounted on said casing for engagement by said movable contact element throughout the range of movement of said movable members.

Claim 23

An electrical switch operable by a change in the tension transmitted between first and second tension elements, comprising a casing, first and second movable members mounted in said casing for movement therein and having means for connecting said movable members to the respective first and second tension elements, said first and second movable members being movable with said first and second tension elements, said first and second movable members having means interconnecting said members for relative lost motion between first and second positions, the normal transmission of tension between said tension elements being effective to cause relative movement of said first and second movable members to said first position, resilient means acting between said first and second movable members and biasing said members for relative movement to said second position, and switching means operable between two different switching states in response to relative movement of said first and second movable members between said first and second positions, whereby one of said switching states is produced by normal transmission of tension between said tension elements, whiLe the other switching state is produced in the absence of such transmission of tension, said first movable member comprising a carriage movable in said casing, said second movable member being slidably mounted on said carriage, said resilient means comprising spring means acting between said carriage and said second movable member, said switching means comprise stationary contact means on said casing, movable contact means mounted on one of said movable members, and camming means operable by relative movement between said carriage and said second movable member for moving said movable contact means into engagement with said stationary contact means.

Claim 24

An electrical switch operable by a change in the tension transmitted between first and second tension elements, comprising a casing, first and second movable members mounted in said casing for movement therein and having means for connecting said movable members to the respective first and second tension elements, said first and second movable members being movable with said first and second tension elements, said first and second movable members having means interconnecting said members for relative lost motion between first and second positions, the normal transmission of tension between said tension elements being effective to cause relative movement of said first and second movable members to said first position, resilient means acting between said first and second movable members and biasing said members for relative movement to said second position, and switching means operable between two different switching states in response to relative movement of said first and second movable members between said first and second positions, whereby one of said switching states is produced by normal transmission of tension between said tension elements, whiLe the other switching state is produced in the absence of such transmission of tension, said first movable member comprising a carriage movable in said casing, said second movable member being slidably mounted on said carriage, said resilient means comprising spring means acting between said carriage and said second movable member, said switching means comprise stationary contact means on said casing, movable contact means mounted on one of said movable members, and camming means operable by relative movement between said carriage and said second movable member for moving said movable contact means into engagement with said stationary contact means.

Claim 25

An electrical switch according to claim 15, in which said stationary contact means comprise a pair of elongated contact elements on said casing, said movable contact means comprising a pair of contactors movable into and out of engagement with said stationary contact elements, said camming means being operable to move said contactors into and out of engagement with said stationary contact elements.

Claim 26

An electrical switch operable by a change in the tension transmitted between first and second tension elements, comprising a casing, first and second movable members mounted in said casing for movement therein and having means for connecting said movable members to the respective first and second tension elements, said first and second movable members being movable with said first and second tension elements, said first and second movable members having means interconnecting said members for relative lost motion between first and second positions, the normal transmission of tension between said tension elements being effective to cause relative movement of said first and second movable members to said first position. resilient means acting between said first and second movable members and biasing said members for relative movement to said second position, and switching means operable between two different switching states in response to relative movement of said first and second movable members between said first and second positions, whereby one of said switching states is produced by normal transmission of tension between said tension elements, while the other switching state is produced in the absence of such transmission of tension, said first movable member including a carriage movably mounted in said casing, said second movable member including a sleeve movable on said carriage, said sleeve having elements limiting the range of lost motion between said sleeve and said carriage, said switching means including a pair of movable contact arms swingably mounted on said sleeve, a pair of stationary contact elements mounted on said casing, and means operable by relative movement between said carriage and said sleeve for moving said contact arms into and out of engagement with said stationary contact elements.

Claim 27

An electrical switch operable by a change in the tension transmitted between first and second tension elements, comprising a casing, first and second movable members mounted in said casing for movement therein and having means for connecting said movable members to the respective first and second tension elements, said first and second movable members being movable with said first and second tension elements, said first and second movable members having means interconnecting said members for relative lost motion between first and second positions, the normal transmission of tension between said tension elements being effective to cause relative movement of said first and second movable members to said first position. resilient means acting between said first and second movable members and biasing said members for relative movement to said second position, and switching means operable between two different switching states in response to relative movement of said first and second movable members between said first and second positions, whereby one of said switching states is produced by normal transmission of tension between said tension elements, while the other switching state is produced in the absence of such transmission of tension, said first movable member including a carriage movably mounted in said casing, said second movable member including a sleeve movable on said carriage, said sleeve having elements limiting the range of lost motion between said sleeve and said carriage, said switching means including a pair of movable contact arms swingably mounted on said sleeve, a pair of stationary contact elements mounted on said casing, and means operable by relative movement between said carriage and said sleeve for moving said contact arms into and out of engagement with said stationary contact elements.

Claim 28

A switch according to claim 17, in which said last-mentioned means include camming means operable by said sleeve and engageable with said contact arms.

Claim 29

A vehicle safety control system, including an engine having a speed control member movable between minimum and maximum speed positions, including an engine having a speed control member movable between minimum and maximum speed positions, a flexible control cable having a first end connected to said speed control member and movable therewith, resilient means biasing said speed control member and said control cable toward said minimum speed position, said control cable having a second end, stop means limiting movement of said second end of said control cable toward said minimum speed position whereby said resilient means normally maintains tension in said control cable, and switching means connected into said control cable and operable to a first switching state by the normal tension in saId control cable, said switching means including means for operating said switching means to a second switching state when the tension in said cable is diminished, said engine having an electrical stopping system connected to said switching means and effective to stop the engine when said switching means is operated to said second switching state, whereby said engine is stopped automatically when tension is lost in said control cable, said control cable including first and second sections, said switching means being connected between said sections, said switching means including first and second movable members connected to and movable with said first and second sections, means interconnecting said movable members for relative lost motion between first and second relative positions, resilient means acting between said movable members in opposite to the normal tension in said cable, movable contact means on one of said movable members, stationary contact means opposite said movable contact means, and means operable by relative movement between said movable members for moving said movable contact means into and out of engagement with said stationary contact means.

Claim 30

A vehicle safety control system, including an engine having a speed control member movable between minimum and maximum speed positions, including an engine having a speed control member movable between minimum and maximum speed positions, a flexible control cable having a first end connected to said speed control member and movable therewith, resilient means biasing said speed control member and said control cable toward said minimum speed position, said control cable having a second end, stop means limiting movement of said second end of said control cable toward said minimum speed position whereby said resilient means normally maintains tension in said control cable, and switching means connected into said control cable and operable to a first switching state by the normal tension in saId control cable, said switching means including means for operating said switching means to a second switching state when the tension in said cable is diminished, said engine having an electrical stopping system connected to said switching means and effective to stop the engine when said switching means is operated to said second switching state, whereby said engine is stopped automatically when tension is lost in said control cable, said control cable including first and second sections, said switching means being connected between said sections, said switching means including first and second movable members connected to and movable with said first and second sections, means interconnecting said movable members for relative lost motion between first and second relative positions, resilient means acting between said movable members in opposite to the normal tension in said cable, movable contact means on one of said movable members, stationary contact means opposite said movable contact means, and means operable by relative movement between said movable members for moving said movable contact means into and out of engagement with said stationary contact means.

Claim 31

A vehicle safety control system, including an engine having a speed control member movable between minimum and maximum speed positions, a flexible tension member having a first end connected to said speed control member and movable therewith, resilient means biasing said speed control member and said tension member toward said minimum speed position, said tension member having a second end, stop means limiting movement of said second end of said tension member toward said minimum speed position whereby said resilient means normally maintains tension in said tension member, and switching means connected to said tension member and operable to a first switching state by the normal tension in said tension member, said switching means including means for operating said switching means to a second switching state when the tension in said tension member is diminished, said engine having an electrical stopping system connected to said switching means and effective to stop the engine when said switching means is operated to said second switching state, whereby said engine is stopped automatically when tension is lost in said tension member, said tension member including first and second elements, said switching means being connected between said elements, said switching means including first and second movable members connected to and movable with said first and second elements, means interconnecting said movable members for relative lost motion between first and second relative positions, resilient means acting between said movable members in opposition to the normal tension in said tension member, movable contact means on one of said movable members, stationary contact means opposite said movable contact means, and means operable by relative movement between said movable members for moving said movable contact means into and out of engagement with said stationary contact means.

Claim 32

A vehicle safety control system, including an engine having a speed control member movable between minimum and maximum speed positions, a flexible tension member having a first end connected to said speed control member and movable therewith, resilient means biasing said speed control member and said tension member toward said minimum speed position, said tension member having a second end, stop means limiting movement of said second end of said tension member toward said minimum speed position whereby said resilient means normally maintains tension in said tension member, and switching means connected to said tension member and operable to a first switching state by the normal tension in said tension member, said switching means including means for operating said switching means to a second switching state when the tension in said tension member is diminished, said engine having an electrical stopping system connected to said switching means and effective to stop the engine when said switching means is operated to said second switching state, whereby said engine is stopped automatically when tension is lost in said tension member, said tension member including first and second elements, said switching means being connected between said elements, said switching means including first and second movable members connected to and movable with said first and second elements, means interconnecting said movable members for relative lost motion between first and second relative positions, resilient means acting between said movable members in opposition to the normal tension in said tension member, movable contact means on one of said movable members, stationary contact means opposite said movable contact means, and means operable by relative movement between said movable members for moving said movable contact means into and out of engagement with said stationary contact means.

Claim 33

A system according to claim 20, in which said last-mentioned means comprise a camming element movable with one of said movable members and engageable with said movable contact means.

Claim 34

A system according to claim 20, in which at least one of said contact means is elongated to provide for engagement between said movable and stationary contact means throughout the range of movement of said movable members.