JPH0418279Y2 - - Google Patents

Description

[Detailed description of the invention] -Field of industrial application- This invention relates to a spring return switch used in telephone hook switches, etc., and is characterized by the structure of the return spring of the swinging lever that opens and closes the contacts of the switch. This relates to spring return switches.

-Prior art- In a spring return switch that opens and closes a contact by pushing the operating end of a swing lever, the spring force of the return spring of the swing lever and the spring force of the contact spring of the switch are applied to the operating end. It acts as a force that resists force. The force from the contact spring, as shown by line segment R _C in Figure 7, exhibits a characteristic that increases approximately in proportion to the pushing stroke S of the operating end according to Hook's law, so The force from the return spring acts on the operating end so that it has a downward-sloping characteristic as shown by the line segment R _S in Figure 7 at the operating end.
By making sure that the sum R of the forces R _C and R _S is approximately constant,
A structure has been put into practical use that reduces the operating force F of the switch at the operating end.

The force from the return spring is applied to the seventh lever at the operating end of the swing lever.
Conventionally, a structure as shown in FIG. 4 or 5 has been adopted in order to obtain a downward-sloping characteristic as shown by the line segment R _S in the figure. Here, FIG. 4 uses a tension coil spring 30 as a return spring, and FIG. 5 uses a compression coil spring 31. 1 is a switch base, 9
is a swinging lever pivotally supported on the switch base 1 by a support shaft 6. The support shaft 6 and the swinging lever 9 are integrated, and as shown in FIG. Contacts B and M are opened and closed by bending springs 3 and 4. As a result, the spring force of the contact springs 3 and 4 acts on the swing lever 9 via the contact pieces 7 and 8,
A force R _C that resists the operating force F acts on the operating end 10 .

Reference numeral 15 designates a fixed-side engaging portion provided on the switch base 1, 14 represents a movable-side engaging portion provided on the swing lever 9, and return springs 30 and 31 connect both engaging portions 14 and 1.
It is mounted between 5. The solid line in the figure shows the return state of the swing lever, and the return springs 30, 3 at this time
The spring force of 1 is T ₁ , the distance between the line of action of spring force T ₁ and the support shaft 6 (moment arm) is L ₁ , and the spring force of the return spring when operating the switch shown by the imaginary line is T ₂ , this The line of action of the spring force T ₂ and the support shaft 6
The distance from is L ₂ . Naturally, T ₁ < T ₂ as a characteristic of the springs 30 and 31, but the springs are designed so that when the swing lever 9 is pushed, the moment arm decreases from L ₁ to L ₂ to a greater extent than the rate of change of the spring force. 3
0 and 31 so that the return moment, which is the product of both, satisfies T ₁ ×L ₁ > T ₂ ×L ₂ , and the force from the return spring acting on the operating end 10 of the swing lever 9
This is because R _S has a downward-sloping characteristic as shown in Figure 7.

Here, to add a little bit to Fig. 7 (the same applies to Fig. 8), f in the figure indicates the frictional force that acts when swinging the swing lever 9, and the return spring returns the swing lever 9. To do this, over the entire stroke S, the force R _T obtained by subtracting the frictional force f resisting this from the sum R of the return force R _S from the return spring and the return force R _C from the contact spring is the load O. It must be above the line by a margin e. Further, the operating force F required to press down the operating lever 9 is the sum R of the above-mentioned return force acting as a resistance force, plus the frictional force F.
It must be above the applied force R _U by a margin g. Therefore, the relationship between these forces is as shown in FIG. 7 or 8. Here, FIG. 7 shows a case where the force R _S acting on the operating end by the return spring has a downward-sloping characteristic, and FIG. 8 shows a case where the force R S acts on the operating end has a downward-sloping characteristic.

-Problems to be Solved by the Invention- In order to make the force R _S from the return spring acting on the operating end 10 of the swing lever downward to the right according to the above principle, the change in the moment arm ΔL=L ₁ -
Although L ₂ must be increased, in order to increase ΔL, it is necessary to separate the engaging portions 14 and 15 of the springs 30 and 31 from the support shaft 6 of the operating lever 9.
A problem arises in that the distance k between the fixed side engaging portion 15 and the support shaft 6 and the height h from the mounting surface 25 of the switch to the upper ends of the springs 30, 31 become high, making it difficult to downsize the switch. In addition, since the fixed side and movable side engaging parts 15 and 14 are separated, the change characteristic of the force R _S from the return spring acting on the operating end 10 with respect to the pushing stroke S corresponds to the difference in contact configuration, etc. If an attempt is made to change the angle of inclination (such as the inclination angle of the line segment R _S in Fig. 7), the design becomes complicated because the movable side or fixed side engaging parts 14 and 15 must be moved significantly, and in some cases In some cases, it may not be possible to obtain optimal change characteristics.

In addition, in order to downsize the switch, there is a structure in which a torsion helical spring 32 directly applies a return moment about the support shaft 6 to the swing lever 9, as shown in FIG. 6, but in this structure, Although the switch can be made smaller, the force R _S from the return spring 32 acting on the operating end 10 of the swing lever 9
The problem is that the switch has an upward slope characteristic as shown in FIG. 8, and the operating force F of the switch becomes large.

This invention solves the above problems and allows the switch to be made smaller and requires less operating force, as well as a spring return structure that allows for easy setting of the force from the return spring that acts on the operating end of the swing lever. The purpose is to obtain a switch.

- Means for solving the problem - Explaining using the reference numerals of the illustrated embodiments, the spring return switch of this invention has a swinging lever 9 that opens and closes the contacts M and B of the switch. The movable lever is extended beyond its support shaft 6, and has an engaging portion 1 on the movable side of the return spring 20 at its extended end.
4 is provided, and the fixed side engaging part 15 provided on the switch base 1 is provided on the above-mentioned extension side of the movable side engaging part 14. As a return spring for returning the swing lever 9, a torsion helical spring 20 is used, in which both ends 21 and 22 of a coiled wire extend in the tangential direction of the coil. 20 is mounted with both ends 21 and 22 being engaged with the movable side engaging part 14 and the stationary side engaging part 15.

-Operation- The switch of this invention utilizes the same principle as shown in Figs. 4 and 5 as a structure for reducing the operating force of the switch. , 22 and the rate of change of the spring force with respect to the amount of deflection can be reduced.
The distance between 5 and 14 can be shortened. By arranging the torsion helical spring 20 on the side of the switch base 1 at a position that does not overlap the swing lever 9, the switch can be configured extremely compactly. Furthermore, since the position of the spring 20 can be freely selected without interfering with the support shaft 6 or the swing lever 9, and the engaging parts 15 and 14 on the fixed side and the movable side are close to each other, it is possible to By slightly changing the position of the movable side engaging portions 15 and 14, the direction of the line of action of the spring force T can be freely changed. The force R _S from the return spring 20 can be freely set.

-Embodiment- Figures 1 to 3 show an embodiment of this invention, in which 1 is a switch base, 2 is a cover, 3 and 4 are contact springs whose base ends are fixed to the switch base 1, and 5 is a contact plate on the receiving side, 6 is a support shaft rotatably supported on the switch base 1, 7 and 8 are push contact pieces integrated with the support shaft 6, and 9 is a swing lever integrated with the support shaft 6. In the return state shown by the solid line in FIG. 3, the pressing piece 8 presses down the contact spring 4 and opens the contact M.
The push contact piece 7 separates from the contact spring 3, and the contact spring 3 contacts the contact plate 5 by its own spring force, and the contact B
is closed. And the operating end 10 of the swinging lever 9
When is pressed down, the support shaft 6 swings clockwise in the figure, the push contact piece 8 separates from the contact spring 4, and the contact M is closed, and the push contact piece 7 pushes down the contact spring 3 to close the contact B. open. That is, the switch of the illustrated embodiment has two make contacts M and two break contacts B.

The swinging lever 9 has arms 11 and 12 on both sides thereof.
The base end of one arm 12 is connected to both ends of the support shaft 6, but the base end of one of the arms 12 extends beyond the support shaft 6, and a return spring 20 is attached to the tip of the extension 13.
An engaging portion 14 on the movable side is formed. A stationary side engaging part 15 is formed on the side surface of the switch base 1 at a position further in the extension direction of the movable side engaging part. Moving side and fixed side engaging parts 14, 15
is installed in a direction parallel to the support shaft 6 between a lower protrusion 17 having holding pieces 16, 16 erected on both sides and an upper protrusion 18 protruding upward at a slight angle above the center thereof. Both ends 21, 2 of the bent return spring 20
2 is fitted and secured by its spring force.

A torsion helical spring is used as the return spring 20 of the swing lever 9, and the torsion helical spring 20 applies spring force to the engaging portions 14 and 15 by extending a wire in the tangential direction of the coil. Both ends 21 to be acted upon,
22 is formed, and is mounted so as to convert the torsional repulsive force of the coil into an expanding force at both ends 21 and 22, and to act as a compression spring. Spring 20 when the swinging lever 9 returns as shown by a solid line in FIG.
The direction of the spring force is indicated by the arrow _T1 , and the distance between its line of action and the support shaft 6 is _L1 . Furthermore, the direction of the spring force of the spring 20 in the state shown by the imaginary line in _FIG .
The distance from is L ₂ . Then, the movable side and fixed side engaging parts 14, 15 are adjusted so that T _{1 ×} L ₁ > T ₂ ×L 2.
By setting the position of , the downward-sloping characteristic shown by R _S in FIG. 7 is realized.

In the structure shown in FIG. 1, the torsion helical spring 20 is mounted upside down so that the line of action of the spring force passes above the support shaft 6, and the engaging portion 14,
The switch of this invention can also be constructed by making the spring 15 hook-shaped and having a structure in which both ends 21 and 22 of the spring are engaged from the outside, and a torsion helical spring 20 having a similar structure is made to act as a tension spring.

-Effects of the Invention- According to the structure of the invention described above, the return spring of the swing lever can be mounted compactly and the switch can be made very small for the reason explained in the section of the operation. Also, based on the same principle as the conventional switch shown in Figs. 4 and 5,
It is possible to obtain a switch with a small operating force, and since the fixed side engagement part and the movable side engagement part of the return spring can be provided close to each other, the swinging can be prevented by a slight change in the mutual position of the engagement parts. The force from the return spring acting on the operating end of the lever can be freely changed, and the effect is that the optimum return force can be easily set according to the contact structure.

[Brief explanation of drawings]

Figures 1 to 3 are views showing one embodiment of this invention, with Figure 1 being a side view, Figure 2 being a plan view with the cover removed, and Figure 3 being part A of Figure 2. FIG. 4, 5, and 6 are side views of conventional switches. FIGS. 7 and 8 are explanatory diagrams showing changes in the force acting on the operating end of the switch with the operating stroke of the switch as the horizontal axis, and the operating stroke as the horizontal axis. In the figure, 1... Switch base, 3, 4... Contact spring, 5... Contact plate, 6... Support shaft, 7, 8... Press contact piece, 9... Rocking lever, 10... Operating end. , 13...
... Lever extension part, 14 ... Moving side engaging part, 1
5... Fixed side engaging part, 20... Return spring (torsion helical spring), 21, 22... Both ends thereof, M,
B...Contact point.

Claims (1)

[Scope of utility model registration request] The swinging lever that opens and closes the switch contacts is extended beyond its support shaft, and the extended end is provided with a movable side engagement part of the return spring, and the fixed side engagement part provided on the switch base is provided on the movable side. A torsion helical spring, which is provided on the extension side of the engaging part and has both ends of a coiled wire extending in the tangential direction of the coil, connects the movable engaging part and the fixed side. 1. A spring return switch, characterized in that the spring return switch is mounted such that both ends thereof are engaged with an engagement portion.