Stackable low profile electrical contact blocks

Abstract

To provide a stackable low profile electrical contact block.SOLUTION: A stackable electrical contact block 100 includes a housing that has top and bottom surfaces and houses a first electrical terminal 108 and a second electrical terminal 110, an actuating pusher 112 adapted to move from a resting position Pr to an actuating position that breaks the electrical contact between the first electrical terminal 108 and the second electrical terminal 110, and having a head 130 protruding from the top surface, a clearance below the actuating pusher, and a return spring 114 that urges the actuating pusher 112 toward the resting position, and whose lower end extends into the clearance.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a stackable electrical contact block, comprising a housing defining a volume, the housing having a top surface and an opposite bottom surface, - a first electrical terminal and a second electrical terminal; - an actuation pusher adapted to move between a rest position and an actuation position to establish or interrupt electrical contact between the first electrical terminal and the second electrical terminal, the actuation pusher having an actuation head protruding from an upper surface of the housing in the rest position; a clearance provided below the actuating pusher when the actuating pusher is in its rest position; a return spring biasing the actuating pusher towards its rest position, the return spring having a lower end extending into the clearance; is provided. [Background technology]

[0002] Electrical contact blocks of this type are known, an example of which is disclosed in Figures 1 and 8-10 of WO 2015 / 091497.

[0003] Such contact blocks have the advantage of being low profile. However, their inability to be fully stackable limits their use as modules, for example as part of a push button assembly. In particular, this prior art contact block cannot be used as the top or middle member of a stack of contact blocks. Summary of the Invention [Problem to be solved by the invention]

[0004] SUMMARY OF THE INVENTION In view of the above, it is an object of the present disclosure to provide a low profile electrical contact block that is fully stackable. [Means for solving the problem]

[0005] According to the present disclosure, this object is achieved by an electrical contact block as defined in paragraph

[0001] above, characterized in that the bottom surface of the housing is configured as a connection interface with an entrance providing access to a clearance for connecting the contact block to another component, the central part of the clearance being occupied by the lower end of a return spring, and the peripheral part of the clearance being an actuating head receiving space surrounding the central part and adapted to receive an actuating head of a component connected to the contact block via the connection interface.

[0006] By using the bottom surface of the housing as a connection interface, the contact blocks of the present disclosure can be easily stacked on other components, particularly other contact blocks. When stacking, the opening on the bottom surface allows the actuating head of the lower contact block to be inserted into the clearance of the upper contact block. As a result, the actuating head of the lower contact block is positioned below and can cooperate with the pusher of the upper contact block. By locating the lower end of the return spring in the center of the clearance, the periphery of the clearance is not interfered with, allowing the actuating head of the lower contact block to be inserted into the upper contact block.

[0007] The following features may optionally be implemented separately or in combination with one another. the actuation pusher has an elongated shape defining a central longitudinal pusher axis, and the return spring has a cylindrical shape defining a central longitudinal spring axis, the axes being essentially coincident. - A movable electrical contact bridge establishes and breaks electrical contact between the first terminal and the second terminal, the contact bridge is housed within an actuating pusher, and a return spring extends through the contact bridge. A contact spring biases the contact bridge toward the first and second terminals, and a return spring extends through the contact spring. - The contact spring and return spring are arranged coaxially. The contact bridge has a central through-hole that is traversed by a return spring. the inlet consists of two parallel slits adapted to receive the protrusions of the fork-shaped working head; A spring support is formed on the bottom surface of the housing to support the lower end of the return spring, and the spring support is located between two parallel slits. - the actuating pusher is essentially H-shaped when viewed from the side. The actuating head of the actuating pusher is fork-shaped. - The housing has a height-to-length ratio of less than 0.4.

[0008] These and other features and advantages are detailed in the following description of the preferred embodiment and the accompanying drawings. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a side view of a normally closed type electrical contact block according to the present disclosure. [Figure 2] FIG. 2 is a side view similar to FIG. 1 with the housing cover removed. [Figure 3] FIG. 3 is a cross-sectional view of the electrical contact block taken along line III-III in FIG. [Figure 4] FIG. 4 is a bottom view taken along arrow IV in FIG. [Figure 5] FIG. 5 is a perspective view of an actuation pusher according to the present disclosure. [Figure 6] FIG. 6 is a perspective view of an electrical contact bridge according to the present disclosure. [Figure 7] FIG. 7 is a stack of two electrical contact blocks of the present disclosure, one normally closed and one normally open. [Figure 8] FIG. 8 is a cross-sectional view of the stack of FIG. 7 taken along line VIII-VIII. [Figure 9] FIG. 9 is a perspective view showing details of the stack of FIG. [Figure 10] FIG. 10 is a side view of a stack of two electrical contact blocks of the present disclosure, both of the normally closed type, both in their actuated positions. [Figure 11] FIG. 11 is a perspective view of a push button assembly according to the present disclosure including four electrical contact blocks. DETAILED DESCRIPTION OF THE INVENTION

[0010] Referring first to Figures 1-4, these figures illustrate an embodiment 100 of a stackable electrical contact block according to the present disclosure.

[0011] The electrical contact block 100 is designed to be integrated into a control unit such as an industrial push button assembly (see FIG. 11). Activating the electrical contact block 100 can interrupt electrical contact between two electrical terminals located within the contact block. In industrial applications, this can be used to stop the supply of current to electrically powered equipment. For example, the electrical contact block 100 can be used as part of an emergency stop push button to stop a production line in the event of a fault.

[0012] Generally, there are two types of electrical contact blocks: normally open electrical contact blocks and normally closed electrical contact blocks (the abbreviations for these are NO for "normally open" and NC for "normally closed").

[0013] The electrical contact block 100 shown in Figures 1 to 4 is of the NC type. It should be understood that the present disclosure covers not only NC type contact blocks, but also NO type contact blocks.

[0014] 1 to 4, the electrical contact block 100 includes a housing 102 that defines its overall volume. The housing 102 is composed of a housing cover 102a and a housing main body 102b. The cover 102a is fitted to the side of the main body 102b. In FIG. 2, the cover 102a has been removed to show the internal structure of the electrical contact block 100. The housing 102 has a top surface 104 and a bottom surface 106 on the opposite side.

[0015] The electrical contact block 100 is a first electrical terminal 108 and a second electrical terminal 110; - an actuating pusher 112; - a return spring 114; a movable electrical contact bridge 116; - a contact spring 118; - Two wire inlet pairs 120 and 122; all of which reside within the housing 102.

[0016] The two wire inlet pairs 120, 122 are located on opposite sides of the housing 102. In other words, a first side of the housing 102 has two wire inlets, and an opposite second side of the housing 102 also has two wire inlets. In the figures, only one wire inlet of each pair 120, 122 is visible on each side of the housing 102. Figures 7 and 10 show the electrical contact block 100 with an electrical wire W inserted therein, such that the electrical wire W makes electrical contact with one of the two terminals 108, 110.

[0017] The bottom surface 106 and the top surface 104 of the housing 102 are each configured as connection interfaces for connecting the contact block 100 to other components. In this manner, the contact block 100 can be stacked, for example, on top of other contact blocks. Similarly, other contact blocks can be stacked on top of the illustrated contact block 100. This is shown in Figures 7-10. Thus, the electrical contact block 100 can be assembled with other components to construct a control device, such as an emergency stop push button assembly.

[0018] When another contact block is attached to the top surface 104 of the contact block 100, it is secured using the double hook 124 and the opposite securing shoe 126.

[0019] The bottom connection interface, i.e., the housing bottom 106, has an inlet 128 as shown in Figure 4. Preferably, the inlet consists of two parallel slits 128a, 128b.

[0020] The actuation pusher 112 can move between a rest position Pr and an actuation position Pa to establish and interrupt electrical contact between the first terminal 108 and the second terminal 110. Because the contact block shown in Figures 1-4 is of the NC type, the rest position Pr is a closed position in which the contact bridge 116 bridges the gap between the two electrical terminals 108, 110. In this closed position, current can flow from one terminal to the other. All figures except Figure 10 show the actuation pusher 112 in the closed or rest position Pr. In Figure 10, the actuation pusher 112 is depressed and in its actuation position Pa.

[0021] The actuation pusher 112 is shown by itself in FIG. 5. It has an actuation head 130, a cross link 136, a spring end receiving zone 132 located on the cross link 136, and a bridge guide base 134 in the form of two protrusions (left and right). The actuation head 130 and the base 134 are connected via the cross link 136. The actuation pusher 112 has an elongated shape that defines a central longitudinal pusher axis XX. As shown in FIG. 3, for example, the actuation pusher 112 has an essentially H-shaped configuration when viewed from the side. Note also that the actuation head 130 of the actuation pusher 112 is fork-shaped. The fork 130 has two protrusions 130a and 130b.

[0022] 2 and 3, the bridge guide base 134 has a fork shape with a first protrusion 134a and a second protrusion 134b. As is clear from FIG. 2 and FIG. 3, the movable contact bridge 116 is housed between the two base protrusions 134a, 134b. Each protrusion 134a, 134b functions as one of the outer guide walls for the movable bridge 116 so that the movable bridge 116 can slide up and down within the actuation pusher 112.

[0023] The outer sidewall of first protrusion 134a functions as a guide surface for guiding the sliding movement of movable bridge 116. A guide slot 138 is disposed in second protrusion 134b. The inner wall of guide slot 138 also functions as a guide surface for guiding the sliding movement of movable bridge 116.

[0024] Turning now to FIG. 6, the movable electrical contact bridge 116 is a metal element having two lateral electrical contacts 116a, 116b, a central through-hole 116c, a guide notch 116d, and a guide protrusion 116e. The guide notch 116d cooperates with the outer sidewall of the unslotted guide protrusion 134a. Together, the guide notch 116d and the outer sidewall thus form an outer guide assembly. The guide protrusion 116e fits into a guide slot 138 in the second guide protrusion 134b. Together, the guide protrusion 116e and the guide slot 138 thus form an inner guide assembly. Overall, the sliding motion of the movable bridge 116 is guided by two lateral guide assemblies: an outer guide assembly and an opposing inner guide assembly.

[0025] Alternatively, the movable bridge 116 may be guided by two outer guide assemblies or two inner guide assemblies. In the first case, both guide projections 134a, 134b are slotless, and the movable bridge 116 will have two opposing guide notches 116d. In the second case, both guide projections 134a, 134b have guide slots 138, and the movable bridge 116 will have two opposing guide protrusions 116e.

[0026] Each contact 116 a , 116 b cooperates with one of the electrical terminals 108 and 110 .

[0027] In the illustrated embodiment, the return spring 114 is a helical-type compression spring. As can be seen in FIG. 3 , it has a lower end 114a near the bottom surface 106 of the housing and an upper end 114b near the top surface 104 of the housing. The return spring 114 has a cylindrical shape defining a central longitudinal spring axis YY. The longitudinal spring axis YY coincides with the longitudinal pusher axis XX. The return spring 114 extends through the contact bridge 116. More specifically, the return spring 114 traverses the central through-hole 116c. The function of the return spring 114 is to bias the actuating pusher 112 toward its rest position Pr. To do so, its upper end 114b presses against the pusher 112, and its lower end 114a presses against the housing 102.

[0028] The upper end 114b of the return spring 114 is received in the spring end receiving zone 132 of the actuation pusher 112. Also, a spring support 140 is formed on the bottom surface 106 of the housing. The spring support 140 supports the lower end 114a of the return spring 114. As shown in FIG. 4, the spring support 140 is located between the two parallel slits 128a, 128b.

[0029] As best seen in FIG. 9 , when the actuation pusher 112 is in the rest position Pr, a clearance 142 is located below the actuation pusher 112. The lower end 114a of the return spring 114 extends into the clearance 142. An entrance 128, i.e., two slits 128a and 128b, provides access to the clearance 142. The central portion 142a of the clearance 142 is occupied by the lower end 114a of the return spring 114. The peripheral portion 142b of the clearance 142 surrounding the central portion 142a is the actuation head receiving space. As seen in FIGS. 7-9 , the actuation head receiving space 142b is adapted to receive the actuation head 130 of a component connected to the contact block via its bottom surface 106. The actuation head receiving space 142b is subdivided into two separate receiving zones. Each zone is capable of receiving one of two prongs 130 a , 130 b of a fork-shaped working head 130 .

[0030] Referring to FIG. 2, the contact spring 118 biases the contact bridge 116 toward the first terminal 108 and the second terminal 110. As shown in FIG. 3, the contact spring 118 is fitted into the base 134 of the actuation pusher 112. The upper portion of the contact spring 118 presses against the bottom surface of the contact bridge 116. The lower portion of the contact spring 118 rests on a shelf 144 of the base 134. In the illustrated embodiment, the contact spring 118 is a helical compression spring. Therefore, it has a cylindrical shape. As shown in FIG. 3, the return spring 114 extends through the contact spring 118. Preferably, the contact spring and the return spring are coaxially arranged. In this case, they share a common longitudinal axis YY. Preferably, the diameter of the return spring 114 is smaller than the diameter of the contact spring 118.

[0031] The operation of the electrical contact block 100 will now be described. In the rest position Pr, the actuating head 130 protrudes from the top surface 104 of the housing (see FIGS. 1 and 2). The electrical contact block 100 is actuated by pushing the actuating pusher 112 into the housing 102. This is done by depressing the actuating head 130. The pressure acting on the actuating head 130 must be sufficient to overcome the opposing force exerted by the return spring 114. The actuating pusher 112 then moves toward the bottom surface 106 of the housing until it reaches the actuated position Pa shown in FIG. 10. In this position, the actuating head 130 is fully retracted within the housing 102. The movable contact bridge 116, which moves integrally with the actuating pusher 112, moves away from the electrical terminals 108 and 110. Thus, electrical contact between the first terminal 108 and the second terminal 110 is interrupted.

[0032] To attach a contact block to the bottom surface 106 of the contact block 100, the protrusions 130a, 130b of the contact block's actuating head 130 must be inserted into the parallel slits 128a, 128b in the contact block 100. In this way, the protrusions 130a, 130b fit into the actuating head receiving space 142 of the contact block 100. As can be seen in Figures 7-9, when two contact blocks are assembled to form a stack, the two protrusions 130a, 130b of the actuating head 130 of the lower contact block are positioned directly below the actuating pusher of the upper contact block. Therefore, when the upper actuating pusher is pressed down, a downward force is transmitted directly to the lower actuating pusher, actuating both contact blocks simultaneously.

[0033] 7-9 show a stack in which the upper contact block is a normally open block 200 and the lower contact block is a normally closed block. The scope of this disclosure extends to these NO type contact blocks, which have similar inventive configurations with respect to bottom entry, clearance below the actuation pusher, and placement of the return spring, contact spring, and contact bridge.

[0034] 11 is a perspective view of a push button assembly 300 including two stacks 302 and 304 of two contact blocks according to the present disclosure. The left stack 302 is made of an upper NC-type contact block 100 and a lower NO-type contact block 200. The right stack 304 is made of an upper NO-type contact block 200 and a lower NC-type contact block 100. Thus, assembly 300 has a total of four contact blocks. Using collars 306, the four contact blocks are attached to a push button 308.

[0035] A feature of the contact blocks 100, 200 of the present disclosure is their low profile. In fact, the ratio of the height h to the length l of the contact block housing 102 is typically less than 0.4 (see FIG. 1). The small height h allows more contact blocks 100, 200 to be assembled behind the collar 306 and still fit into slim control panels.

[0036] The new contact block structure described in this disclosure is particularly suited to meet all current customer needs. - The new contact blocks 100, 200 are compatible with state-of-the-art contact blocks. This means, among other things, that the new contact blocks 100, 200 can be stacked underneath existing contact blocks. The new contact blocks 100, 200 are completely stackable on top of each other, regardless of the stacking order. - More of the new contact blocks 100, 200 of the present disclosure can be fitted in the same available head space compared to conventional contact blocks which are taller.

[0037] Additionally, the contact blocks 100, 200 of the present disclosure are fully compliant with industry safety standards for clearance and creepage distances.

[0038] The present disclosure is not limited to the particular embodiments described herein, which are merely exemplary, and the present invention encompasses all alternatives that remain covered by the appended claims.

Claims

1. A stackable electrical contact block (100) comprising a housing (102) defining a volume thereof, said housing (102) having a top surface (104) and an opposite bottom surface (106), said housing (102) including: a first electrical terminal (108) and a second electrical terminal (110); an actuating pusher (112) adapted to move between a rest position (Pr) and an actuated position (Pa) to establish or interrupt electrical contact between said first terminal (108) and said second terminal (110), said actuating pusher (112) having an actuating head (130) protruding from the upper surface (104) of said housing in said rest position (Pr); a clearance (142) provided below said actuating pusher when said actuating pusher is in said rest position (Pr); a return spring (114) biasing said actuating pusher (112) towards its rest position, said return spring (114) having a lower end (114a) extending into said clearance (142); a movable electrical contact bridge (116) for establishing and breaking electrical contact between said first terminal (108) and said second terminal (110); is established, the bottom surface (106) of the housing is configured as a connection interface with an inlet (128) providing access to the clearance (142) for connecting the contact block (100) to another component; a central portion (142a) of the clearance is occupied by the lower end (114a) of the return spring (114), and a peripheral portion (142b) of the clearance is an actuation head receiving space surrounding the central portion (142a) and adapted to receive the actuation head (130) of a component connected to the contact block (100) via the connection interface; The stackable electrical contact block (100) is characterized in that the contact bridge (116) is housed within the actuation pusher (112), and the return spring (114) extends through the contact bridge (116).

2. 2. The contact block (100) of claim 1, wherein the actuation pusher (112) has an elongated shape defining a central longitudinal pusher axis (X-X) and the return spring (114) has a cylindrical shape defining a central longitudinal spring axis (Y-Y), both axes being essentially coincident.

3. 3. The contact block (100) of claim 1, further comprising a contact spring (118) that biases the contact bridge (116) toward the first terminal (108) and the second terminal (110), the return spring (114) extending through the contact spring (118).

4. The contact block (100) of claim 3, wherein the contact spring (118) and the return spring (114) are coaxially disposed.

5. The contact block (100) according to any one of claims 1 to 4, wherein the contact bridge (116) has a central through hole (116c) traversed by the return spring (114).

6. The contact block (100) according to any one of claims 1 to 5, wherein the inlet (128) is configured with two parallel slits (128a, 128b) adapted to receive the protrusions (130a, 130b) of the fork-shaped actuating head (130).

7. 7. The contact block (100) of claim 6, further comprising a spring support (140) formed on the bottom surface (106) of the housing for supporting the lower end (114a) of the return spring, the spring support (140) being located between the two parallel slits (128a, 128b).

8. The contact block (100) according to any one of the preceding claims, wherein the actuation pusher (112) has an essentially H-shaped configuration when viewed from the side.

9. The contact block (100) according to any one of the preceding claims, wherein the actuating head (130) of the actuating pusher is fork-shaped.

10. The contact block (100) according to any one of the preceding claims, wherein the ratio of the height (h) to the length (l) of the housing is less than 0.4.

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