JPH0312196Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a time switch that has a protrusion on its shaft and a cam that is rotated by the action of the protrusion.

[Prior art]

Conventionally, when attaching a cam to the shaft of a time switch, the shaft 3 is supported by a case 1 and a fixing member 2, as shown in FIGS. Through hole 9a to be engaged
A long cylindrical collar 13 is fitted to the shaft 3 below the cam 9, and the cam 9 is locked with the collar to prevent it from falling toward the gear 5 that is engaged with the shaft 3. Ta.

Therefore, assembly is time-consuming, and the use of a long collar increases material costs.

Further, the pin 10 is in direct line contact with the fixing member 2, and the pin 10 is supported by a leaf spring 11 that presses the gear 5 downward.
Since it is pressed, it provides frictional resistance to the rotation of the shaft 3, and when the shaft 3 is strongly pulled upward as shown in FIG. It has the disadvantage that it tends to hang and deform.

[Purpose of invention]

In view of the above drawbacks, the present invention prevents the cam from falling by providing a rib on the cam that the protrusion cannot pass through, and a protrusion receiving member is fitted into the circular groove so that when the shaft is pulled, the protrusion receiving member is attached to the fixed member. It is an object of the present invention to propose a time switch which prevents a local load from being applied to a fixing member through surface contact and prevents ribs from being pressed against the fixing member by projections.

[Structure of the idea]

In the present invention, a projection is provided on the shaft, a cam having an engagement recess that engages with the projection and a shaft insertion hole is rotatable by the rotation of the shaft, and the force of thrust movement of the shaft is transmitted through the projection. In the time switch which is received by a fixed member, a circular groove is formed on the outer periphery of the shaft insertion hole on the side of the fixed member of the cam, and a portion of the groove facing the engagement recess is a through hole. On the other hand, the cam is provided with a rib through which the protrusion cannot pass, and a protrusion receiving member is slidably fitted in the groove, so that the force of thrust movement of the shaft is received through the protrusion receiving member. There is a particular thing.

〔Example〕

The present invention will be explained below with reference to illustrated embodiments. In the time switch, as shown in Fig. 1, a shaft 3 is supported by a case 1 and a fixing member 2, and is fixed so that a pin 10 protruding from the shaft 3 protrudes from both sides.A cam 4 is fitted on the outer periphery of the shaft 3, and the cam A pin 10 is fitted into the engagement recess 4a of 4 and is rotatably engaged with the rotation of the shaft 3. A stepped portion is provided on the shaft 3 on the side of the case 1, and the rotating pawl plate or leaf spring 11 having elasticity is fitted with the gear 5 and the washer 12, and the gear 5 is prevented from coming off by caulking, and a spring hook 6 is attached to the gear 5. The starting end of mainspring 7 is latched.

As shown in FIGS. 2 to 5, the cam 4 has a shaft insertion hole 4b in the center, the engagement recess 4a on the lower side, and a circular shape concentric with the shaft insertion hole 4b on the upper side. A circular groove 4c is formed, and a portion of the groove 4c facing the engagement recess 4a is a through hole 4d, and a rib 4e through which the pin 10 cannot pass is provided between the through hole 4d and the shaft insertion hole 4b. It is provided. In the groove 4c, a ring-shaped protrusion receiving member 8 made of a metal material or a hard synthetic resin material is installed in the groove 4c as shown in FIG.
The pin 10 side surface of the rib 4e is lower than the groove bottom surface 4f by an amount h, that is, the rib 4e is formed thinner than the protrusion receiving member 8. ing. In FIG. 1, a pin 10 whose length is longer than the outer diameter of the protrusion receiving member 8 is used, and the pin 10 is formed to a length that fits within the engagement recess 4a. The height H of the projection receiving member 8 is larger than the width H' from the bottom surface 4g of the cam 4 to the surface 4i of the rib 4e on the pin side.

Once the time switch is configured as above,
The rib 4e of the cam 4 rests on the pin 10 and does not fall.
A gap is provided between the cam 4 and the fixed member 2, so that the cam 4 and the pin 10 are not in constant contact with the fixed member 2, and when the shaft 3 is strongly pulled, a ring is formed between the pin 10 and the fixed member 2. shaped projection receiving member 8
are slidably and rotatably interposed, and the fixed member 2
Since the protrusion receiving member 8 and the protrusion receiving member 8 are in surface contact with each other, the fixing member 2
Since the load applied to the fixing member 2 is made uniform and no local load is applied, deformation of the fixing member 2 is less likely to occur. Further, by using the protrusion receiving member 8 which is higher than the depth of the circular groove 4c, the surface of the rib 4e on the pin 10 side is lower than the groove bottom surface 4f by an amount h, so there is a sufficient gap in the thrust direction and the cam 4 is in a free state. Also, material costs are reduced since there is no need to use long collars.

Furthermore, conventionally, as shown in FIG. 13, the cam 9 has continuous through-holes 9a that lack the shaft insertion hole 9b, so the contact area between the cam 9 and the shaft 3 is small, and radial play is avoided. However, the shaft insertion hole 4b of the cam 4 is formed as a round hole. Since the contact area with the shaft 3 is increased, radial play is less likely to occur, the contact pressure of the contacts is stabilized by smooth rotation in the radial direction, the load on the contacts is reduced, and durability is improved.

In the above explanation, the case where the upper surface of the cam 4 and the upper surface of the rib 4e are on the same plane is illustrated, but in FIG. Using the low protrusion receiving member 8, the surface of the rib 4e on the pin 10 side is moved h from the groove bottom surface 4f.
The height H of the protrusion receiving member 8 is
The same effect as described above can be obtained by making the width H' larger than the width H' from the bottom surface 4g of the cam 4 on the fixed member side to the surface 4i of the rib 4e on the protrusion side.

In the above description, the cam 4 is formed so as to have two ribs 4e, but the cam 4 may be made to have only one rib 4e by omitting one or by doing as shown in FIG. 7.

Further, in the above description, the protrusion receiving member 8 is formed in a ring shape, but it may be formed in a split ring shape as shown in FIG. 8, or as a two-part ring as shown in FIG. 9. Furthermore, as shown in FIG.
It is also possible to fit into the circular groove 4c with the end a facing the fixing member 2 side.

Alternatively, the rib 4e may not be provided, and the pedestal 4k on the outer periphery of the groove 4c may be used as a rib to prevent the cam from falling. Further, in each of the above embodiments, the surface of the protrusion on the fixing member side is a horizontal plane, but it may be structured so that only the portion that contacts the protrusion receiving member protrudes. In addition, at this time, H >H' must be set,
There is no need to provide a gap at the h portion.

[Effect of idea]

As described above, the present invention is provided with ribs that cannot be passed through by the protrusions, and these ribs prevent the gum from falling, simplifying the structure, making it easier to assemble, and eliminating the need for a collar, reducing material costs. Furthermore, since the movement of the shaft toward the fixed member is received by the protrusion receiving member, even if the shaft is strongly pulled, the cam remains in a free state and does not affect the cam operation. Furthermore, since the protrusion receiving member is brought into surface contact with the fixing member and no local load is applied to the fixing member, it is possible to provide a time switch which has excellent practical effects such as preventing deformation of the fixing member. .

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a cross-sectional side view of the main part of a time switch, FIG. 2 is a plan view of the cam, FIG. 3 is a back view of the cam, and FIG. 5 is a sectional side view taken along the - line in FIG. Fig. 7 is a cross-sectional side view of the main part when there is only one rib, Fig. 8 is a plan view of a modification in which the protrusion receiving member is formed in the shape of a split ring, and Fig. 9 is a plan view of a modification in which the protrusion receiving member is formed in the form of a two-part ring. FIG. 10 is a perspective view of a protrusion receiving member having a protrusion formed on its upper surface. 1st
Figure 1 is a cross-sectional side view of the main parts of a conventional time switch.
FIG. 12 is a plan view of the time switch, and FIG. 13 is a plan view of the cam and shaft. 2... Fixed member, 3... Shaft, 4... Cam, 4a
...Engaging recess, 4b...Shaft insertion hole, 4c...Circular groove, 4d...Through hole, 4e...Rib, 8...Protrusion receiving member, 10...Pin (protrusion).

Claims (1)

[Scope of utility model registration request] A projection is provided on the shaft, and a cam having an engagement recess that engages with the projection and a shaft insertion hole is rotatable by rotation of the shaft, and the force of thrust movement of the shaft is received by the fixed member via the projection. In the time switch, a circular groove is formed on the outer periphery of the shaft insertion hole on the fixed member side of the cam, and a portion of the groove facing the engagement recess is a through hole; is provided with a rib through which the protrusion cannot pass through, and a protrusion receiving member is slidably fitted in the groove, so that the force of thrust movement of the shaft is received through the protrusion receiving member. Time switch.