JPH028352Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a mechanism for switching the rotation speed according to the Hertz number in timers, time switches, etc.
A shaft 3 for small diameter gears and a shaft 4 for large diameter gears are integrally provided in a cantilevered manner on the side of a switching lever 2 which is switched and rotated around a transmission shaft 1. A small-diameter switching gear 5 and a large-diameter switching gear 6 are rotatably attached to the shaft 4, respectively, and the small-diameter switching gear 5 and the large-diameter switching gear 6 are attached to a driven gear 7 fixed to the transmission shaft 1. In the rotation speed switching mechanism in which one of the small-diameter switching gear 5 and the large-diameter switching gear 6 is switched and meshed with the drive gear 8 by switching rotation of the switching lever 2, at both ends of the connecting rod 9. A connecting member 12 is formed by providing fitting portions 11 having fitting holes 10 and 10, respectively, and a switching holding area for holding two rotational switching positions of the switching lever 2 is formed in the connecting member 12. This relates to a rotational speed switching mechanism in which the coupling holes 10, 10 are respectively fitted to the shaft 4 for large diameter gears and the shaft 3 for small diameter gears, and the connecting member 12 is attached to the tips of the shafts 3, 4 for large and small diameter gears. It is.

Timers, time switches, and the like are often equipped with a mechanism that changes the rotation speed in order to operate according to the Hertz number in regions with different Hertz numbers. Furthermore, in order to reduce the size and cost of these timers, time switches, etc., there is a trend toward molding the rotation speed switching mechanism with a synthetic resin molded product. However, if this mechanism is made of synthetic resin, the shaft that supports the gears is made of synthetic resin, so it may bend or fall due to external or internal loads, and the meshing between the gears may become small, causing chipping or crushing of the tooth tips. There was a fear that this would occur, and that it would eventually lead to malfunction.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a rotation speed switching mechanism that is free from malfunction even when made of synthetic resin material.

The present invention will be explained in detail below with reference to Examples. The switching lever 2 is integrally formed from a synthetic resin material, and has a rotation hole 13 bored in the center as shown in FIG. A shaft 3 for a small-diameter gear and a shaft 4 for a large-diameter gear parallel to the rotation hole 13 are provided in a cantilevered manner at the tips of the support rods 14, 14. The large diameter gear shaft 4 is formed thicker than the small diameter gear shaft 3. Further, a transmission rod 16 having a boss 15 is provided protruding from the side surface of the switching lever 2. This switching lever 2 is rotatably mounted by passing a rotation hole 13 through a transmission shaft 1 pivotally supported on the base of a timer or time switch.
A driven gear 7 is fixed to the upper end of the transmission shaft 1 which passes through the transmission shaft 1. A small diameter switching gear 5 for 50 Hz and a large diameter switching gear 6 for 60 Hz are rotatably attached to the small diameter gear shaft 3 and the large diameter gear shaft 4, respectively. 6 is a driven gear 7
It is tightly interlocked with the Reference numeral 8 denotes a driving gear attached to a driving shaft 17, in which a lower large-diameter gear portion 19 meshes with a small gear 18 to which rotation is transmitted from the motor, and a small-diameter gear portion 20 is connected to the small-diameter switching gear 5 and the large-diameter switching gear. It is designed so that it can mesh with one side of 6. Reference numeral 25 denotes a switching operation lever, which is integrally formed from a synthetic resin material, is rotatably attached to the base body, and has a transmission rod 22 having a long hole 21 protruding from its side surface. A boss 15 of the switching lever 2 is inserted into the elongated hole 21. The connecting member 12 is made of a synthetic resin material and is integrally formed in a flat plate shape.As shown in FIG. A spring connecting rod 23 having spring properties is installed between them. A positioning protrusion 24 is provided protruding from the center of the spring connecting rod 23.

Therefore, in the case shown in FIG. 4 in which the connecting member 12 is not used, when the driving gear 8 rotates clockwise (arrow a), the small diameter switching gear 5 is connected to the driving gear 8 and the driven gear. Since it receives the force of the arrow b that bites into the gear 7, there is no particular problem even if the small diameter gear shaft 3 is bent. However, when the driving gear 8 rotates counterclockwise (arrow C), the small-diameter switching gear 5 receives a force in the opposite direction d, and due to the deflection of the small-diameter gear shaft 3, the driving gear 8 and the driven gear 7 The meshing of the small diameter switching gear 5 with the small diameter switching gear 5 becomes shallow, and there is a risk that chipping or crushing of the tooth tips may occur, resulting in malfunction. The same can be said of the large-diameter switching gear 6.

Therefore, as shown in FIG. 2, the fitting holes 10, 10 provided in the fitting parts 11, 11 are fitted to the tips of the small diameter gear shaft 3 and the large diameter gear shaft 4, and the connecting member 12 is connected to both shafts. 3 and 4. That is, in the 50 Hz region, by meshing the small-diameter switching gear 5 with the driving gear 8 as shown in Figure 2a, the rotation of the driving gear 8 is transmitted to the driven gear 7 without much deceleration. However, by connecting the tip of the small-diameter gear shaft 3 to the tip of the large-diameter gear shaft 4 using the connecting member 12, the large-diameter gear shaft 4 is reinforced and the small-diameter gear shaft 3 is prevented from bending. This is to prevent it from falling over. In particular, the deflection of the small diameter gear shaft 3 in the tangential direction to the driven gear 7 of the small diameter switching gear 5 is prevented by the connecting rod 9 of the connecting member 12, and the deflection of the small diameter gear shaft 3 in the normal direction is prevented by the spring of the connecting plate 12. This is prevented by the connecting rod 23. Here, since the large diameter gear 6 has a large diameter, the large diameter gear shaft 4 can be made thicker to accommodate this (if the small diameter gear shaft 3 is made thicker, the larger diameter gear 6 can be made thicker). It is necessary to increase the diameter of the small-diameter switching gear 5, and therefore the small-diameter switching gear 5 and the driven gear 7 also have to be formed with even larger diameters, which goes against the desire for compactness.) This serves to reinforce the small diameter switching gear 5. When used in a 60 Hz region, the large diameter switching gear 6 should be engaged with the driven gear 7 by turning the switching operation lever 25 with a knob or the like and turning the switching lever 2 as shown in FIG. 2b. As a result, the rotation of the driving gear 8 is transmitted to the driven gear 7 with a large deceleration. In this case as well, the large-diameter gear shaft 4 is reinforced in the same manner as described above, and since the large-diameter gear shaft 4 is formed thick, it is also reinforced.

Note that by locking the tip of the driving shaft 17 of the driving gear 8 to the positioning protrusion 24 provided on the spring connecting rod 23 of the connecting member 12, the small diameter switching gear 5 or the large diameter switching gear 6 can be connected to the driving gear 8. Meshing is the second
As shown in Figures a and b, the spring connecting rod 23 is bent when the switching lever 2 is rotated, and the positioning protrusion 24 moves the seal 17 from the left to the right or from the right. By moving the lever to the left, it is possible to switch between states a and b in FIG. 2, and the switching lever 2 is click-operated. That is, on both sides of the positioning protrusion 24 provided on the connecting rod 23, switching holding areas are formed for holding the switching lever 2 in two rotational switching positions. In the figure, reference numeral 26 denotes a lifting prevention piece provided on the switching lever 2, which is engaged with a presser protrusion 27 basically provided to prevent the switching lever 2 from lifting up.

This invention forms a connecting member by providing fitting parts each having a fitting hole at both ends of a connecting rod, and fitting the fitting holes into a shaft for a large-diameter gear and a shaft for a small-diameter gear, respectively, to form a connecting member. is attached to the tip of the shaft for large and small diameter gears, so the shafts for large and small diameter gears, which are cantilevered from the switching lever, are connected by a connecting member, and the This has the advantage of suppressing the deflection of the shaft for small-diameter gears and eliminating misalignment caused by the deflection of the shaft. That is, the switching lever is provided with a shaft for a small diameter gear and a shaft for a large diameter gear integrally in a cantilevered manner, and the technical problem of engagement failure caused by deflection of the shaft due to the cantilevered protrusion has been solved. It has been resolved.
Therefore, even if the switching lever is made of a synthetic resin molded product, it is possible to prevent both shafts from bending or deforming, and it has become possible to make the switching mechanism a synthetic resin molded product. This allows cost reduction and miniaturization. Moreover, since the connecting member is formed with a switching holding area that holds the switching lever in two rotational switching positions, as described above,
When the shaft for large and small diameter gears is provided cantilevered on the switching lever, the connecting member is effectively used to eliminate the deflection of the shaft for large and small diameter gears, and this allows the switching lever to maintain two rotational switching positions. By forming a switching holding area that allows the switching area to be rotated, the connecting member can have the function of holding the switching area, which is necessary when rotating the switching lever, and has the advantage that the configuration for holding the switching area can be simplified. There is.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view of an embodiment of the present invention, Figs. 2 a and b are top views of the same, Fig. 3 is a top view of the connecting member of the above, and Fig. 4 is the case where the connecting member of the above is not used. It is a top view showing the effect of. 1 is a transmission shaft, 2 is a switching lever, 3 is a shaft for small diameter gears, 4 is a shaft for large diameter gears, 5 is a small diameter switching gear, 6
is a large diameter switching gear, 7 is a driven gear, 8 is a driving gear, 9 is a connecting rod, 10 is a fitting hole, 11 is a fitting part,
12 is a connecting member.

Claims (1)

[Scope of utility model registration request] A small-diameter gear shaft and a large-diameter gear shaft are integrally provided in a cantilevered manner on the side of the switching lever that switches and rotates around the transmission shaft, and the small-diameter gear shaft and large-diameter gear shaft can be switched to the small-diameter gear shaft and the large-diameter gear shaft, respectively. The small-diameter switching gear and the large-diameter switching gear are rotatably mounted, and the small-diameter switching gear and the large-diameter switching gear are meshed with the driven gear fixed to the above-mentioned transmission shaft, and the driving gear is used to rotate the switching lever. In the rotation speed switching mechanism in which one of the small-diameter switching gear and the large-diameter switching gear is switched and meshed with each other, a connecting member is formed by providing fitting portions each having a fitting hole at both ends of the connecting rod. A switching holding area for holding the switching lever in two rotational switching positions is formed in the connecting member, and the fitting hole is fitted to a shaft for a large diameter gear and a shaft for a small diameter gear respectively, so that the connecting member is connected to a shaft for a large and small gear. A rotation speed switching mechanism attached to the end of the shaft.