CN113258369A

CN113258369A - Door contact switch

Info

Publication number: CN113258369A
Application number: CN202110527384.2A
Authority: CN
Inventors: 王辉
Original assignee: Bernstein Safe Solutions Taicang Co ltd
Current assignee: Bernstein Safe Solutions Taicang Co ltd
Priority date: 2021-05-14
Filing date: 2021-05-14
Publication date: 2021-08-13
Also published as: WO2022237785A1

Abstract

The invention discloses a door contact switch. The door contact switch comprises a socket and a plug which can be mutually inserted, wherein the socket comprises a shell, a conducting strip arranged in the shell and a connecting piece which is arranged in the shell and is used for connecting an external lead, the plug is provided with an inserting rod, one end part of the conducting strip is provided with a contact which is used for being contacted and conducted with the plug, the other end part of the conducting strip is electrically connected with the connecting piece, the connecting piece comprises a body and at least two wire clamping pieces, the body is arranged on the shell or the conducting strip and is conducted with the conducting strip, the wire clamping pieces extend from the body along a threading direction and are provided with a leading-in end connected with the body and a clamping end which is a distance away from the body, the socket is provided with an initial or maintenance state that the external lead is not connected, in an initial or maintenance state, the distance between the clamping ends of the wire clamping piece is smaller than the outer diameter of the external lead, and the wire clamping piece has elasticity and can allow the external lead to pass through the clamping ends. The invention has convenient and reliable wiring and reduces the risk of poor contact.

Description

Door contact switch

Technical Field

The invention belongs to the field of door contact switches, and relates to a door contact switch, in particular to a door contact switch of an elevator door.

Background

The elevator safety door contact switch is mainly used for controlling the closing and opening of an elevator car door and an elevator landing door, and protecting the safety of elevator passengers and the normal operation of an elevator. The door contact switch among the prior art adopts the wiring mode of screw-up mostly, need just can accomplish the connection of wire and door contact switch with the help of specialized tool, and the installation is complicated, and is influenced by operating personnel's skill level, easily causes contact failure scheduling problem, still needs regular maintenance.

For example, chinese patent document CN206976189U discloses a currently commonly used elevator door switch, which includes a plug and a socket that can be inserted into each other, two insertion rods are integrally formed and protrudingly disposed in the middle of the plug, insertion holes adapted to the insertion rods are disposed in the middle of the upper side of the socket, two V-shaped reeds are respectively arranged in the socket in a left-right symmetric manner, two fixing posts are respectively integrally disposed in the socket in a left-right symmetric manner, bent portions of the two V-shaped reeds are respectively sleeved on the two fixing posts in a corresponding manner, silver contacts are respectively disposed at one ends of the two V-shaped reeds close to the insertion holes, the insertion rods are respectively inserted into the socket along the insertion holes and abut against the silver contacts, two connection screws are respectively integrally disposed in the socket in a left-right symmetric manner, and the other ends of the two V-shaped reeds are respectively connected to the two connection screws in a corresponding manner. The elevator door switch has the problems of complex installation and large risk of poor contact.

Disclosure of Invention

In view of the above technical problems, the present invention provides a door contact switch, which is convenient and reliable in wiring and has less risk of poor contact.

A door contact switch comprises a shell, a conducting strip arranged in the shell and a connecting piece which is arranged in the shell and used for connecting an external lead, wherein a plug is provided with an inserting rod, one end part of the conducting strip is provided with a contact which is used for being in contact with the inserting rod, the other end part of the conducting strip is electrically connected with the connecting piece, the connecting piece comprises a body and at least two wire clamping pieces, the body is arranged on the shell or the conducting strip and is communicated with the conducting strip, the wire clamping pieces extend from the body along the threading direction and are provided with a leading-in end connected with the body and a clamping end which is a distance away from the body, a socket is provided with an initial state or a maintenance state which is not connected with the external lead, and when the initial state or the maintenance state is carried out, the distance between the clamping ends of the at least two wire clamping pieces is smaller than the external lead, the wire clamping piece has elasticity and can allow the external lead to pass through the clamping ends.

In some preferred embodiments, the distance between the lead-in ends of at least two of the wire clamps is greater than the distance between the clamping ends.

In some more preferred embodiments, at least one of the wire clamps extends obliquely from the lead-in end to the clamping end in a manner of gradually approaching a center line, and the center line can be coincident with the center line of the accessed external lead.

Furthermore, the space enclosed by the wire clamping piece is conical as a whole.

In some preferred embodiments, the body is formed with a threading hole for the external lead to pass between the thread clamping members.

In some preferred embodiments, the connecting member is integrally formed of metal.

In some preferred embodiments, the socket further comprises a release member capable of being inserted between the clamping members to spread the clamping ends apart to release the external lead.

In some more preferred embodiments, the housing includes a body having a pressing through hole and a tongue piece located in the pressing through hole and allowing pressing, a part of the tongue piece is connected to the body, the releasing member is located on an inner surface of the tongue piece, the releasing member extends inward from the inner surface of the housing along a releasing direction, the tongue piece has elasticity and can be pressed toward the wire clamping member so that the releasing member is inserted between the wire clamping members, and an included angle between the releasing direction and the threading direction is greater than 45 degrees and smaller than 135 degrees. The tongue piece is pressed down, the release piece on the inner surface of the tongue piece moves inwards, the release piece is inserted between the wire clamping pieces, the clamping ends of the wire clamping pieces are propped open, the external lead between the clamping ends is released and can be pulled out of the socket, the external lead can be conveniently replaced or maintained, auxiliary tools are not needed, the working time is saved, and the efficiency is improved.

Furthermore, the tongue piece is provided with a pressing part positioned in the pressing through hole and a connecting end connected with the hole wall of the pressing through hole, and a gap is formed between the pressing part and the hole wall of the pressing through hole.

Further, the pressing portion is recessed inward compared to other portions of the housing.

Optionally, the whole body is strip-shaped or U-shaped, and only one end or one side of the whole body is connected with the hole wall of the pressing through hole.

Further, the release member is a projection formed on an inner surface of the tongue.

In some specific and preferred embodiments, the connector further comprises a wire removal guide provided at the clamping end of the wire clamping member and/or at a portion adjacent to the clamping end, the wire removal guide having a guide slope guiding the release member for insertion between the wire clamping members.

More preferably, the release member has a contact slope cooperating with the guide slope.

In some preferred embodiments, the housing is further provided with an insertion hole for the insertion rod to be inserted into so as to contact the contact of the conductive sheet, the profile of the insertion hole has a plurality of outward-protruding outward-expanding portions, adjacent outward-expanding portions are connected through a transition portion, the transition portion is a straight line or an outward-protruding arc line, the insertion hole has a geometric center, and a distance between the outward-expanding portion and the geometric center is greater than a distance between the transition portion and the geometric center. When the elevator door reaches a preset height, the inserted rod of the plug is inserted into the jack of the socket, the top end of the inserted rod is abutted against the contact of the conducting strip, the conducting strip is conducted to generate an electric signal, and the electric signal is transmitted to a control system of the elevator door through an external wire connected with the conducting strip through a connecting piece, so that the opening and closing of the elevator door are controlled. The jack adopts the heterotypic shape that has a plurality of outer portions that expand, has increased the cooperation space when the inserted bar inserts and can guarantee again that the inserted bar correctly inserts and contact with the contact and switch on, has higher reliability.

More preferably, the flaring portion is comprised of an arc and has a curvature greater than the connecting portion.

Further, the distance from the center line of the jack to the flaring portion is greater than the distance from the center line to the transition portion.

Further, expand the quantity of portion outward for two and relative setting, two expand the portion outward through two arc connection of evagination and enclose into a closed profile.

Furthermore, the outline of the jack takes an axis which is vertically crossed with the axis of the jack as a symmetrical axis to form an axisymmetrical pattern, or takes the center line of the jack as a center to form a centrosymmetric pattern.

Compared with the prior art, the invention has the following advantages by adopting the scheme:

according to the door contact switch, the external lead is inserted into the wiring through hole of the connecting piece, the elastic force of the wire clamping piece is overcome, the external lead passes through the clamping ends and is clamped by the clamping ends, the wiring can be automatically pressed, stable mechanical connection and electric connection are realized, the wiring is simple and convenient, poor contact is avoided, and frequent maintenance is not needed; and no other tool is needed for assistance in the wiring process (for example, no screw fastening tool is needed), and the installation is convenient.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a door contact switch according to an embodiment of the present invention.

Fig. 2 is a schematic structural diagram of a socket according to an embodiment of the present invention, in which an upper case is not shown.

Fig. 3 is a top view of a receptacle according to an embodiment of the present invention, with the upper shell not shown.

Fig. 4 is a schematic structural diagram of two conductive sheets in fig. 1.

Fig. 5 is a partial enlarged view of a portion a in fig. 4.

Figure 6 is a side view of the conductive sheet of figure.

Fig. 7 is a schematic structural view of an upper case of a socket according to an embodiment of the present invention;

FIG. 8 is a schematic view of the inner surface of the upper shell of FIG. 7;

fig. 9 is a schematic view of one side of a receptacle according to an embodiment of the present invention.

Fig. 10 is a schematic view of the left side jack of fig. 9.

Wherein:

100-a socket;

1-a shell; 11-a lower shell; 111-jack; 111 a-flaring portion; 111 b-a transition; 111 c-geometric center; 112-wiring vias; 12-upper shell; 120-pressing the through hole; 121-tongue piece; 122-buckling;

2-a conductive sheet; 21-a contact;

3-a connector; 31-a body; 31 a-a threading hole; 32-a wire clamp; 321-a lead-in end; 322-a clamping end; 323-a guide block for removing stitches; 324-space; 33-rivets;

4-a release member;

200-plug; 201-insert rod.

Detailed Description

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that the advantages and features of the invention may be more readily understood by those skilled in the art. It should be noted that the description of the embodiments is provided to help understanding of the present invention, but the present invention is not limited thereto.

According to one embodiment of the invention, a door contact switch, in particular an elevator door contact switch, is provided. Referring to fig. 1, the door contact switch includes a socket 100 and a header 200 that are pluggable into each other. The plug 200 has two insertion rods 201, two insertion holes 111 are provided on the socket 100 to be matched with the insertion rods 201, and the insertion rods 201 can be inserted into the corresponding insertion holes 111.

Referring to fig. 2 to 9, the socket 100 includes a housing 1, a conductive plate 2 disposed in the housing 1, and a connector 3 disposed in the housing 1 for connecting an external wire (which is not a component of the door contact switch and is connected to the socket only after being mounted on the elevator door, and thus is not shown). One end of the conductive plate 2 is provided with a contact 21 for contacting and conducting with the insertion rod 201 of the plug 200, and the other end of the conductive plate 2 is electrically connected with the connector 3. The conductive sheet 2 is a spring made of a conductive material, such as metal or alloy, and bent to have elasticity. The number of the conductive plates 2 is two and symmetrically arranged to correspond to the two insertion rods 201 of the plug 200. The contact 21 may be a conductive bump disposed on one end of the conductive plate 2, and when the insertion rod 201 is inserted, the end of the insertion rod 201 and the contact 21 are in tight contact with each other, so as to be conducted with each other. The connecting piece 3 is used for realizing mechanical connection and electrical connection with an external lead, and transmitting an electric signal through the external lead (such as a signal wire), for example, transmitting the electric signal to a control system of an elevator door; when the insertion rod 201 of the plug 200 is inserted into the socket 100 and abuts against the contact 21, an electric signal is generated by triggering, and the electric signal is transmitted to the control system through an external lead, so that the opening of the elevator door can be controlled.

In this embodiment, the connecting member 3 is disposed on the other end of the conductive plate 2, and the two are electrically connected. The connecting member 3 is integrally formed of a conductive material, for example, a metal sheet or an alloy sheet by punching, cutting, or the like. Specifically, as shown in fig. 5, the connecting member 3 includes a body 31 and at least two wire clamping members 32. The body 31 is arranged on the conducting plate 2 and communicated with the conducting plate 2, and the body 31 is connected to the conducting plate 2 through a rivet 33; the body 31 is formed with a threading hole 31a for the external lead to pass through between the thread clamping members 32, and a central line C of the threading hole 31a is a threading direction of the external lead. The threading hole 31a is formed by bending the metal sheet into a C-shape, i.e. the wall of the hole surrounding the threading hole 31a is not completely closed but has a small gap. The number of the wire clamps 32 is two or three or four or more, and a space 324 for accommodating the external lead is defined between the wire clamps 32. The thread clamping member 32 extends from the body 31 in the threading direction and has a lead-in end 321 connected to the body 31 and a clamping end 322 spaced from the body 31. The socket 100 has an initial or maintenance state in which the external wires are not connected, in which the distance between the clamping ends 322 of at least two wire clamping members 32 is smaller than the outer diameter of the external wires, and the wire clamping members 32 have elasticity to allow the external wires to pass through between the clamping ends 322. During wiring, the clamping end 322 is spread; after the external lead penetrates into the clamping end 322, the external lead is clamped between the clamping ends, so that the external lead is effectively prevented from loosening, and the risk of poor contact is reduced.

The distance between the leading-in ends 321 of the thread clamping pieces 32 is greater than the distance between the clamping ends 322, at least one thread clamping piece 32 extends obliquely from the leading-in end 321 to the clamping end 322 in a manner of gradually approaching to the center line C of the threading hole 31a, and the center line C of the threading hole 31a can be overlapped with the center line of the accessed external lead. Thus, the space 324 enclosed by the wire clamp 32 is generally pyramidal or conical in shape. Specifically, each of the thread clamping members 32 extends obliquely from the lead-in end 321 to the holding end 322 so as to gradually approach the center line C of the threading hole 31a, and a space 324 in the shape of a regular pyramid with a gradually decreasing cross-sectional area is defined between the thread clamping members 32. The wire clamping member 32 is disposed obliquely to guide the external wire to pass through, so that the external wire can approach and enter the clamping end 322.

The socket 100 further comprises a releasing member 4 which can be inserted between the wire clamping members 32 to expand the clamping ends 322 to release the external wires; when the wiring is wrong or the external lead needs to be maintained and replaced, the clamping end 322 of the wire clamping piece is opened by operating the releasing piece 4, and the external lead is pulled out to be separated from the connecting piece 3. Further, the releasing piece 4 can be movably arranged on the shell 1 along a releasing direction, an included angle which is larger than 0 and smaller than 180 degrees is formed between the releasing direction and the threading direction, the included angle is preferably larger than 45 degrees and smaller than 135 degrees, and further is larger than 60 degrees and smaller than 120 degrees; in particular, in this embodiment, the release direction and the threading direction are spatially perpendicular to each other.

The casing 1 mainly comprises an upper casing 12 and a lower casing 11, wherein the upper casing 12 is provided with a plurality of buckles 122, and the upper casing 12 and the lower casing are mutually clamped through the buckles 122. A space in which the conductive sheet 2 and the connector 3 are arranged is formed in the lower case 11, and the upper case 12 covers the lower case 11 to close the space. The conductive plate 2 and the connecting member 3 are located between the upper case 12 and the lower case 11. The upper shell 12 includes a body 31 with a pressing through hole 120 and a tongue piece 121 located in the pressing through hole 120 and capable of being pressed, wherein a part of the tongue piece 121 is connected with the body 31 and a weak portion capable of being elastically deformed is formed at the connection position of the two. The release member 4 is disposed on the inner surface of the tongue 121 and extends downward in the release direction. The release element 4 is embodied as a protrusion formed on the inner surface of the tongue 121, which is shaped like a wedge or a trapezoid from a bottom or top view, fitting into the space enclosed by the wire clamping element 32. Furthermore, the upper case 12 is integrally injection-molded from an insulating material such as plastic, the tongue piece 121 has a pressing portion located in the pressing through hole 120 and a connecting end connected to the hole wall of the pressing through hole 120, and a gap is provided between the pressing portion and the hole wall of the pressing through hole 120. The tongue piece is strip-shaped or U-shaped as a whole, and only one end or one side is connected with the hole wall of the pressing through hole 120. The pressing portion is recessed inward compared to other portions of the upper shell 12. The tongue piece 121 has elasticity, and the releasing piece 4 can be pushed into the space between the wire clamping pieces 32 by pressing the pressing part inwards to open the clamping end 322, so that the external lead can be conveniently maintained or replaced.

Each of the wire clamps 32 further includes a wire-removal guide 323, respectively, the wire-removal guide 323 being located at the clamping end 322 of the wire clamp 32 and/or adjacent to the clamping end 322. The disconnecting guide 323 has a guide slope guiding the release member 4 to be inserted between the clamping members 32, and accordingly, the release member 4 has a contact slope cooperating with the guide slope. As shown in fig. 5, the two stitch removing guide blocks 323 of the two stitch clamping members 32 are disposed opposite to each other, and the guide slopes of the two stitch removing guide blocks are opposite to each other, so as to form a V-shaped or inverted trapezoidal guide space therebetween, so as to guide the releasing member 4, and facilitate the releasing member 4 to enter between the stitch removing guide blocks 323 to open the clamping end 322.

The door contact switch is provided with two conducting strips 2, and two contacts 21 are arranged on the two conducting strips 2; correspondingly, the number of the jacks 111 is two, and the jacks correspond to the number and the positions of the contacts 21 one by one; the number of the connecting members 3 is two, the number of the through holes and the tongues 121 of the upper shell 12 is two, and the number of the releasing members 4 is two, and the number and the positions of the two connecting members 3 correspond to one another.

The above-mentioned insertion hole 111 is specifically opened on the side surface of the lower case 11, and the plug 200 is inserted to approach and contact with the contact 21 on the conductive sheet 2. The two receptacles 111 are identical in shape and mirror-symmetrical with respect to the Y-Y direction in fig. 9. The shape of the insertion hole 111 will be described in detail by taking the insertion hole 111 on the left side in fig. 9 as an example.

Referring to fig. 10, the insertion hole 111 has a geometric center 111c and is a shaped hole with a contour having a plurality of outwardly convex flaring portions 111 a; specifically, the flaring portion 111a projects outwardly relative to a regular reference pattern (e.g., a circle shown by a dashed line in fig. 10) centered about the geometric center 111c, which is outside the regular pattern. Adjacent flared portions 111a are connected by a transition portion 111b, the transition portion 111b is a straight line or an arc that is convex outward, and the distance between the flared portion 111a and the geometric center 111c is greater than the distance between the transition portion 111b and the geometric center 111 c. The transition 111b may be located within or partially coincident with or outside of the reference figures described above, but is less convex than the flared portion 111a, i.e., the transition 111b has a curvature less than the curvature of the flared portion 111 a.

Further, the flaring portion 111a is formed of an arc and has a curvature larger than that of the connecting portion. The contour of the receptacle 111 is centrosymmetric with respect to its geometric center 111 c.

Specifically, in this embodiment, the number of the flaring portions 111a is two and the flaring portions 111a are arranged oppositely, and the two flaring portions 111a are connected by two outward convex arcs and enclose a closed contour, which is an axisymmetric figure. Each flared portion 111a spans the X-X direction and is mirror symmetric with respect to the X-X direction. This shape of the receptacle 111 increases the plug-in fit space of the contact bridge and ensures correct insertion. It should be noted that the line connecting the geometric centers of the two insertion holes 111 extends in the X-X direction, and the line connecting the center lines of the two insertion rods 201 of the plug 200 extends in the X-X direction.

In another embodiment, the number of the flaring portions 111a is four and the flaring portions 111a are arranged opposite to each other in pairs, wherein one pair of the flaring portions 111a spans the X-X direction and the other pair of the flaring portions 111a spans the Y-Y direction.

The shell 1 is provided with wiring through holes 112 for inserting external wires and reaching the connecting pieces 3, and the number and the positions of the wiring through holes 112 correspond to those of the two connecting pieces 3 one by one. The wiring insertion hole 111 is preferably opened on the other side surface of the housing 1 opposite to the insertion hole 111, specifically, on the side surface of the lower case 11. The wire passing hole 112 is aligned with and communicates with the wire passing hole 31a of the connector 3.

The wiring process of the door contact switch of the present embodiment is as follows:

a pair of external conductors are respectively inserted into the two wiring through holes 112, sequentially pass through the wiring through holes 112 and the threading holes 31a, then under the guidance of the wire clamping piece 32, overcome the elastic force of the wire clamping piece and pass through the clamping ends 322, and are clamped by the clamping ends 322, so that the wiring can be automatically compressed, the stable mechanical connection and the electric connection are realized, the wiring is simple and convenient, the poor contact is avoided, and the frequent maintenance is not needed. And no other tool is needed for assistance in the wiring process (for example, no screw fastening tool is needed), and the installation is convenient.

the tongue piece 121 is pressed down, the release part 4 on the inner surface of the tongue piece 121 moves inwards and is in contact with the wire removing guide block 323 of the wire clamping piece 32, under the guiding action of the release part 4, the release part 4 is inserted between the wire clamping pieces 32, the clamping end 322 of the wire clamping piece 32 is propped open, the external lead between the clamping ends 322 is released and can be pulled out of the socket 100, the external lead can be conveniently replaced or maintained, auxiliary tools are not needed, the working time is saved, and the efficiency is improved.

The working principle of the door contact switch of the embodiment is as follows:

when the elevator door reaches a preset height, the two insertion rods 201 of the plug 200 are inserted into the insertion holes 111 of the socket 100, the top ends of the insertion rods 201 are abutted against the contacts 21 of the two conducting strips 2, the conducting strips 2 are conducted to generate an electric signal, and the electric signal is transmitted to a control system of the elevator door through an external wire connected with the conducting strips 2 through the connecting piece 3, so that the opening and closing of the elevator door are controlled. The insertion hole 111 of the present embodiment adopts a special shape having a plurality of outward-expanding portions 111a, which increases the fitting space when the insertion rod 201 is inserted, and can ensure that the insertion rod 201 is correctly inserted and is in contact with the contact 21, thereby having higher reliability.

As used in this specification and the appended claims, the terms "comprises" and "comprising" are intended to only encompass the explicitly identified steps and elements, which do not constitute an exclusive list, and that a method or apparatus may include other steps or elements. As used herein, the term "and/or" includes any combination of one or more of the associated listed items.

It should be noted that, unless otherwise specified, when a feature is referred to as being "fixed" or "connected" to another feature, it may be directly fixed or connected to the other feature or indirectly fixed or connected to the other feature. Further, the description of the upper, lower, left, right, etc. used in the present invention is only with respect to the positional relationship of the respective components of the present invention with respect to each other in the drawings.

It is further understood that the use of "a plurality" in this disclosure means two or more, as other terms are analogous.

While the principles and specific embodiments of this invention have been described above, those skilled in the art, having the benefit of the teachings of this invention, will appreciate numerous modifications and variations there from, falling within the scope of the invention. It will be appreciated by persons skilled in the art that the foregoing detailed description is provided for the purpose of illustrating the invention and is not to be construed as limiting the invention. The scope of the invention is defined by the claims and their equivalents.

Claims

1. The utility model provides a door contact switch, includes socket and the plug that can peg graft each other, the socket includes the casing, locates conducting strip in the casing and locating connecting piece that is used for inserting external conductor in the casing, the plug has the inserted bar, be equipped with on a tip of conducting strip be used for with the inserted bar contacts the contact that switches on, another tip of conducting strip with connecting piece electric connection, offer on the casing and supply external conductor to insert and arrive the wiring through-hole of connecting piece department, its characterized in that: the connecting piece comprises a body and at least two wire clamping pieces, the body is arranged on the shell or the conductive sheet and is communicated with the conductive sheet, the wire clamping pieces extend from the body along the threading direction and are provided with a guide end connected with the body and a clamping end away from the body by a distance, the socket is provided with an initial or maintenance state without being connected with the external lead, in the initial or maintenance state, the distance between the clamping ends of at least two wire clamping pieces is smaller than the outer diameter of the external lead, and the wire clamping pieces have elasticity and can allow the external lead to pass through the clamping ends.

2. The door contact switch of claim 1, wherein: the distance between the leading ends of at least two of the wire clamping pieces is larger than the distance between the clamping ends.

3. The door contact switch of claim 2, wherein: at least one of the wire clamping pieces obliquely extends from the leading-in end to the clamping end in a mode of gradually approaching a central line, and the central line can be overlapped with the central line of the accessed external lead.

4. The door contact switch of claim 1, wherein: the body is provided with a threading hole for the external lead to pass through between the thread clamping pieces.

5. The door contact switch of claim 1, wherein: the connecting piece is integrally formed by metal.

6. The door contact switch of claim 1, wherein: the socket also comprises a releasing piece which can be inserted between the wire clamping pieces to spread the clamping ends so as to release the external lead.

7. The door contact switch of claim 6, wherein: the casing is including offering the body that presses the through-hole and being located press the tongue piece that can supply to press in the through-hole, the part of tongue piece with this body coupling, release locates on the internal surface of tongue piece, just release certainly the internal surface of casing inwards extends along the release direction, the tongue piece has elasticity and can be pressed to the trapping line spare, so that release inserts between the trapping line spare, release direction with constitute between the threading direction and be greater than 45 degrees and be less than 135 degrees contained angles.

8. The door contact switch of claim 7, wherein: the tongue piece is provided with a pressing part and a connecting end, wherein the pressing part is positioned in the pressing through hole, the connecting end is connected with the hole wall of the pressing through hole, and a gap is formed between the pressing part and the hole wall of the pressing through hole.

9. The door contact switch of claim 8, wherein: the pressing portion is recessed inward compared with other portions of the shell.

10. The door contact switch of claim 7, wherein: the tongue piece is strip-shaped or U-shaped as a whole, and only one end or one side part of the tongue piece is connected with the hole wall of the pressing through hole.

11. The door contact switch of claim 6, wherein: the release member is a projection formed on an inner surface of the tongue.

12. The door contact switch of claim 6, wherein: the connecting piece further comprises a stitch removing guide block, the stitch removing guide block is arranged on the clamping end of the thread clamping piece and/or a part close to the clamping end, and the stitch removing guide block is provided with a guide inclined surface which guides the releasing piece to be inserted between the thread clamping pieces.

13. The door contact switch of claim 12, wherein: the release member has a contact ramp surface that interfits with the guide ramp surface.

14. The door contact switch of claim 1, wherein: still seted up on the casing and supplied the inserted bar inserts with the contact the jack of the contact of conducting strip, the profile of jack has a plurality of outside convex outer portions that expand, connects through transition portion between the adjacent outer portion that expands, transition portion is the straight line or the arc line of evagination, the jack has geometric center, expand outward the portion with distance between the geometric center is greater than transition portion with distance between the geometric center.

15. The door contact switch of claim 14, wherein: the flaring portion is formed by an arc line, and the curvature of the flaring portion is larger than that of the connecting portion.

16. The door contact switch of claim 14, wherein: the quantity of expanding the portion outward is two and relative setting, two expand the portion outward through two arc connection and enclose into a closed profile to the evagination.