JPH0314955A - Rotation angle limiting mechanism - Google Patents

Abstract

PURPOSE:To limit the rotation range of a rotating member to that 360 degrees or more by providing a stationary member of cam with a stopper to perform limited rotation. CONSTITUTION:A cam 2 rotates once when a rotation shaft 1 rotates in the arrow mark direction and a first stopper 4a is abutted against a second stopper 4b. When the cam 2 rotates, the second stopper 4b rotates around the fitted part of a stationary member 3, and the rotation is competed after it comes at the position shown by two-dots lines. When the shaft 1 rotates reversedly from this position, it stops at the position shown by the full lines. The limitation is made with an angle of 360 degrees or more. The range of rotation can be limited to an angle below and extreamely close to 360 degrees by changing a distance L. This mechanism needs less parts so that the cost is reduced and provides high accurate rotation angle limit. This mechanism is applicable to that needing 360 degrees or more X-ray radiation range or the rotation mecha nism of ITV apparatus.

Description

[Detailed description of the invention]

[Industrial Application Field 1] The present invention relates to a rotation angle limiting mechanism capable of limiting the rotation angle of a rotating body by 360 degrees or an angle exceeding 360 degrees. [Prior Art] An example of a conventionally known rotation angle limiting mechanism is shown in FIG. In the figure, (1) is the rotation axis,
(2) is a cam. This cam (2) is fixed to the rotating shaft (1). (3) is a stationary body, (4a) is a first stopper, and (4b) is a second stopper. First stopper (
4a) is fixed to the cam (2), and the second stopper (4b> is fixed to the stationary body (3). (5) is an arrow indicating the direction of rotation. Next, the operation will be explained. Cam (2) From the state where the first stopper (4a) of the stationary body (3) and the second stopper (4b) of the stationary body (3) are in the relative position shown by the solid line in FIG.
When the cam (2) rotates in the direction of the arrow (5), the cam (2) rotates to the position shown by the two-dot chain line and stops. These allow the rotation angle to be limited. [Problems to be Solved by the Invention] Since the conventional rotation angle limiting mechanism is configured as described above, even if the limiting angle is set to 36 degrees, the stopper (4)
This is impossible because of the thickness of If the thickness of the stopper (4) is made thinner, the angle becomes closer to 360°, but there is also a limit to this, and there is a problem that it is impossible to achieve a complete angle of 360°. The present invention was made in order to eliminate such drawbacks, and an object of the present invention is to provide a rotation angle limiting mechanism that can limit the rotation angle within a rotation range of 360 degrees or an angle exceeding 360 degrees. [Means for Solving the Problems] A rotation angle limiting mechanism according to the present invention includes a stationary body or a cam provided with a stopper that rotates in a limited manner.

[Function] In the rotation angle limiting mechanism of the present invention, since the stopper that rotates in a limited manner is provided on the stationary body or the cam, the rotary body rotates to an angle of 360° or more than 360° and remains stationary. [Example] Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
In the figure, (1) is a rotating shaft, and (2) is a cam, which is fixed to the rotating shaft (1). (4a) is the first stopper,
It is fixed to the cam (2). (4b) is a second stopper, which is inserted into the freely rotatable fitting portion of the stationary body (3). This fitting part is a substantially V-shaped recess,
The tip of this V is substantially cylindrical. The second stopper (4b) has a portion that rotatably fits into this cylindrical portion. Therefore, this second stopper (4b) is rotatable in a limited manner within the range of the V-shaped extension of the fitting portion of the stationary body. Also, the second stopper (4b
) is lightly held in a freely rotating state by a misalignment prevention bottle (6), and (5) is an arrow indicating the direction of rotation. Next, the operation will be explained. First, the first stopper (
4a) and the second stopper (4b) on the stationary body (3) side is assumed to be in the state shown by the solid line in FIG. 1(A). When the rotating shaft (1) rotates in the direction of the arrow (5), the cam (2) also rotates accordingly. When the cam (2) rotates about one rotation, the first stopper (4a) moves to the second stopper (
This corresponds to 4b). When the cam (2) further rotates, the second stopper (4b) rotates based on the fitting portion of the stationary body (3) and stops rotating when it reaches the relative position shown by the two-dot chain line. Since the second stopper (4b) is lightly held down by the displacement prevention bottle (6) in a freely rotatable state, it will not be displaced or fall from the stationary body (3). Furthermore, if the rotating shaft (1) rotates in the opposite direction from this position, the rotation will stop at the original position shown by the solid line. In this way, the rotation angle is 3
It can be restricted at angles greater than 60°. The thickness of the first stopper (4a) of the cam (2) and the second stopper (4b) on the stationary body (3) side, the rotation center position of the rotating shaft (1), and the rotation center position of the second stopper (4b). It is also possible to limit the angle to less than 360° and very close to 360° by changing the distance L between . Other embodiments will be described. In Figure 2, (1) ~
The steps up to (6) are the same as those in Figure 1 (7a) and (7
b) is a rotation angle adjustment screw attached to a female through hole in the fitting portion of the stationary body (3), and is attached so that its tip abuts the second stopper (4b). The operation is similar to that explained in Figure 1, with the cam (2) pointing towards the arrow (5).
When the rotation angle reaches a certain angle of 3600 or more, the second stopper (4b) rotates one of the rotation angle adjusting screws (7a) (7b) attached to the stationary body (3) (
In this case, the rotation is stopped upon hitting 7b). Still another embodiment will be described in which the angle at which the rotation should be stopped can be finely adjusted by adjusting the amount of entry of the rotation angle adjustment screws (7a) and (7b) into the fitting portion. In Fig. 3, (1) is a rotating shaft, (2) is a cam fixed to the rotating shaft (1) and has a fan-shaped notch, (3) is a stationary body, and (4)
a) represents a first stopper that is loosely fitted onto the rotating shaft (1) and rotates freely; (4b) represents a second stopper that is fixed to the stationary body (3); and (5) represents the direction of rotation. The difference from the embodiment shown in FIG. 2 is that the first stopper (4a) is rotatably provided on the rotating shaft (1). The operation is as follows. When the rotating shaft (1) rotates, the cam (2) also rotates accordingly. When the rotation angle reaches a certain angle of 360' or more, that is, (360+a)', the rotation is stopped. The present invention can be used for limiting the rotation angle of satellite communication antennas, for medical linacs that require an X-ray irradiation range of 360 degrees or more, and for the rotation mechanism of the rotary table of ITV equipment. Effects of the Invention As described above, according to the present invention, since either the first stopper or the second stopper is made rotatable, the apparatus becomes compact. Furthermore, since the number of parts is small, the device can be made at low cost, and the rotation angle can be restricted with high accuracy.

[Brief explanation of drawings]

FIG. 1 is a principle diagram of a rotation angle limiting mechanism illustrating an embodiment of the present invention, with FIG. 1(a) being a plan view and FIG. 1(b) being a side view. FIG. 2 is a principle diagram of another rotation angle limiting mechanism of the present invention.
FIG. 2(a) is a plan view, and FIG. 2(b) is a side view. Fig. 3 is a principle diagram of still another rotation angle limiting mechanism of the present invention, Fig. 3 (a) is a plan view, and Fig. 3 (b) is a side view. Figure 4 shows the principle of a conventional rotation angle limiting mechanism. In the figure, (1) is the rotating shaft, (2) is the cam, (3) is the stationary body, (4a) is the first stopper, (4b) is the second stopper, (5) is the rotation direction, and (6) is the Misalignment prevention bins (7a) and (7b) are angle adjustment screws. In the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] (1) A rotating shaft, a cam fixed to the rotating shaft, a first stopper provided on the cam, a stationary body, and a second stopper provided on the stationary body, the rotating shaft In the rotation angle limiting mechanism, the rotation angle limiting mechanism limits the rotation of the rotating shaft by engaging a first stopper with a second stopper when the rotating shaft rotates, wherein either the first stopper or the second stopper A rotation angle limiting mechanism characterized by being able to rotate in a limited manner relative to an object being carried.