JP2504004Y2 - Breaking device for drafting heads - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a brake device for setting an angle of a drawing head used for a universal parallel ruler, and in particular,
The present invention relates to a braking device for a drafting head with an improved arrangement of operating levers.

[Prior Art] An example of a conventional drawing head will be described with reference to FIG. 3 of the attached drawing. In the figure, (1) is a drawing head.
The drawing head (1) is composed of a support plate (2) connected to a freely parallel arm or a carriage, and a scale attachment plate (3) pivotally attached to the support plate (2), and the scale attachment plate (3). The scale mounting plate (3) is formed so that the scale mounting plate (3) can be fixed at an arbitrary angle by operating the grip portion (4) integrally fixed to the.

Further, a protractor plate (5) and a ratchet wheel (6) connected to the protractor plate (5) are interposed between the support plate (2) and the scale mounting plate (3). Brake mechanism (7) capable of fixing the degree plate (5) and the ratchet wheel (6) to the support plate (2) and the scale mounting plate (3), respectively.
(8) is provided.

That is, when the base line brake lever (9) pivotally attached to the support plate (2) is turned from the front side to the back side in FIG. 3, the brake screwed to the turning shaft (10) of the base line brake lever (9). The piece (11) descends. The T-head (11a) of the brake piece (11) is loosely inserted in a guide groove (12) having a convex cross-section in the upper surface of the protractor plate (5), and the guide groove (12) is Since it is arranged annularly in the circumferential direction of the protractor plate (5), the brake plate (11) is lowered to support the support plate (2).
When the pressure contact between the graduation plate (5) and the graduation plate (5) is released, the graduation plate (5) is rotated integrally with the scale mounting plate (3) by the operation of the grip portion (4). Then, a desired reference line angle is determined by an index marked on the vernier (13) of the support plate (2) and an angle scale (not shown) of the protractor plate (5), and the baseline brake lever (9). As shown in FIG. 3, the brake piece (11) is lifted to rotate the protractor plate (5) against the support plate (2) by rotating it from the back side to the front side, and the scale mounting plate (3).
In addition, the protractor plate (5) is solidified on the support plate (2).

Next, when the scale mounting plate (3) is rotated to an arbitrary angle with respect to the reference line determined by the above-mentioned procedure, the index lever (14) is pushed to the left in the figure to move the scale mounting plate (3). ) The connecting pin (16) loosely inserted in the rotating shaft (15)
However, it rotates counterclockwise about the expanded portion (17) of the intermediate portion as a fulcrum. Then, the index claw operation plate (18) engaged with the lower end portion is moved rightward against the bias of the coil spring (19). Then, the tip portion (20) (right side in FIG. 3) of the index claw operation plate (18) is separated from the claw (21) of the ratchet wheel (6), and the scale mounting plate (3) is divided into the protractor plate (5). ), And when the pressing of the index lever (14) is released, the tip end (20) of the index claw operation plate (18) is fitted again to the claw (21) of the ratchet wheel (6). Then, the scale mounting plate (3) is fixed. Therefore, the fixed angle by the above operation is defined by the interval setting of the claws (21) (21) of the ratchet wheel (6). When fixing the scale mounting plate (3) at an angle other than this fixed angle, Index lever (1
4) is pressed to separate the ratchet wheel (6) from the tip portion (20) of the index claw operation plate (18), the index lever (14) is rotated in the front direction in the figure. Let Then, the pin (22) engaged with the intermediate portion of the index lever (14) is pressed, the brake pad (23) with the pin (22) standing is rotated, and the brake pad (23) is attached to the scale mounting plate. Since it is screwed on the rotating shaft (15) of (3), it moves downward. By this movement, the thrust bearing (24) is pressed against the support plate (2), and the scale mounting plate (3) is fixed to the support plate (2) at an arbitrary angle.

[Problems to be Solved by the Invention] In the above-mentioned conventional drawing head, since the base line brake lever (9) is directly attached to the brake mechanism (7) of the support plate (2), the base line brake lever (9) is Since the distance from the grip portion (4) is large, the operability of the baseline brake lever (9) when the grip portion (4) is gripped is not good. In particular, when the grip portion (4) is largely rotated, the direction of the gripped finger and the position of the baseline brake lever (9) may be displaced, making it difficult to operate with one hand.

Also, the arbitrary angle setting by operating the index lever (14) is required because the braking portion is close to the rotation center because the thrust bearing (24) screwed to the rotation shaft (15) is braked. A large pressure contact force is required to obtain the braking force, and a considerable operating force is required to rotate the index lever (14).

Therefore, the distance between the baseline brake lever (9) and the grip portion (4) is made small, and the center of rotation of the baseline brake lever (9) and the grip portion (4) are made as close as possible to each other at all times. In addition to enabling one-handed operation, the index lever (1
There is a technical problem that needs to be solved in order to provide a drafting head brake device that has improved operability while maintaining a sufficient braking force while reducing the operating force in 4).
The present invention aims to solve the problems.

[Means for Solving the Problems] The present invention has been proposed in order to achieve the above-mentioned object, and is a drafting head mounted on a carriage on a drawing board, and a support plate connected to the carriage. Reference line setting means for pivotally mounting the scale mounting plate and the protractor coaxially, and fixing the protractor plate to the support plate at an arbitrary rotation angle, and an optional scale mounting plate for the protractor plate. In a drafting head having an arbitrary angle setting means for fixing at an angle and a brake mechanism using a brake disc made of a metal thin plate, the brake disc made of a metal thin plate used in the brake mechanism is formed to have a diameter larger than that of the protractor plate. And a base line brake mechanism for braking the brake disc on the support plate and a brake disc on the scale mounting plate. And an arbitrary angle brake mechanism are provided in the vicinity of the tip of the brake disc, and a baseline brake lever for setting a reference line and an index lever for setting an arbitrary angle are loosely fitted to the rotating shaft of the scale mounting plate, respectively. Via the power transmission mechanism having a main drive / passive sector gear, the base line brake lever and the base line brake lever mechanism provided on the support plate are connected.
A braking device for a drafting head in which the index lever and an arbitrary angle brake mechanism provided on a scale mounting plate are connected to form a baseline brake mechanism and an arbitrary angle brake mechanism. Is to be provided.

[Operation] A base line brake lever and an index lever are rotatably loosely fitted to a rotary shaft of a scale mounting plate, and when the base line brake lever is operated to rotate, the rotary motion of the base line brake lever and the passive sector gear is changed. It is transmitted to the brake mechanism provided on the support plate via the power transmission mechanism, and brakes or releases the brake disc coupled to the protractor plate, so that the protractor plate can be freely fixed to and released from the support plate. .

In addition, the rotational movement of the index lever is also transmitted to the brake mechanism provided on the scale mounting plate via the power transmission mechanism having the main and passive sector gears, so that the protractor plate can be fixed to and released from the scale mounting plate. The plate can be fixed to the scale mounting plate at any relative rotation angle.

[Embodiment] An embodiment of the present invention will be described below in detail with reference to FIGS. 1 and 2 of the attached drawings. In FIG. 1, (50) is a drawing head, (51) is a support plate connected to a carriage of a free parallel ruler, (52) is a rotary shaft loosely fitted to the support plate (51), ( 53) is a scale mounting plate connected to the rotating shaft (52). A grip portion mounting plate (54) is fitted on the upper part of the rotating shaft (52) and fixed by a nut (55), and the grip portion (56) is attached to the grip portion mounting plate (54) by a bolt (57). ) (57) ... are fixed so that the scale mounting plate (53) can be rotated.

A protractor plate (58) is rotatably interposed between the support plate (51) and the scale mounting plate (53), and a brake disc (59) formed of a thin metal plate on the protractor plate (58). ) And the ratchet wheel (60) are combined. The brake disc (59) includes a protractor plate (58) and a ratchet wheel (6).
0) and a base line brake mechanism (61) whose outer edge is provided on the support plate (51) and a scale mounting plate (5).
Braking is performed by clamping with the arbitrary angle brake mechanism (62) provided in 3).

The brake (63) provided on the support plate (51) is
With the center pin (64) having a), the brake shoe (6
5) swingably supported by a fixed brake shoe (66) and the brake shoe (65) provided on the support plate (51) so as to face the tip portion of the brake shoe (65). It clamps the brake disc (59). A left screw (67) is screwed into the rear portion of the brake shoe (65), and the head (67a) of the left screw (67) is the center of rotation of the passive sector gear (68) as shown in FIG. Is attached to. The driving sector gear (69) that drives the passive sector gear (68) is
As shown in FIG. 1 and FIG. 1, the support shaft (7) of the support plate (51) is
0) is loosely fitted, and the baseline brake lever (71) is projectingly provided on the other side.

Therefore, when the baseline brake lever (71) is rotated in the front direction in FIG. 1, the left-hand screw (67) rotates counterclockwise by the action of the main drive sector gear (69) and the passive sector gear (68), and the brake is applied. Screw into the shoe (65). Since the tip portion of the left screw (67) is in contact with the stopper screw (72) screwed to the support plate (51), the rear portion of the brake shoe (65) is lifted upward and the center pin (64). The front end portion (65a) presses the brake disc (59) against the fixed brake shoe (66) to stop the rotation of the brake disc (59) and the protractor plate (58). Further, when the baseline brake lever (71) is rotated in the opposite direction to the above-described direction, the clamping pressure of the brake disc (59) is released, and the scale mounting plate (53) is rotated by the rotating operation of the grip portion (56). ) And the graduation board (58) can be integrally rotated to set a reference line by fixing them at an arbitrary angle.

A hollow sub-rotating shaft (73) is loosely inserted inside the rotary shaft (52), and an index lever (74) is fitted on the upper part of the sub-rotating shaft (73). The lower portion of the sub-rotating shaft (73) projects from a hole (75) opened in the scale mounting plate (53), and has a main driving sector gear (76) fixed thereto. A right screw (79) of a brake (78) is fitted at the center of rotation of a passive sector gear (77) that meshes with the main drive sector gear (76), and the index lever (74) is rotated in the front direction. Then, the right screw (79) screwed to the scale mounting plate (53) projects upward and pushes up the rear part of the brake shoe (80). Then
The brake shoe (80) swings around the center pin (81) as a fulcrum like the brake (63) described above, and the brake disc (59) is pressed against the fixed brake shoe (82) at the tip portion (80a). , Scale mounting plate (53) with protractor (5
It can be fixed at any angle with respect to 8).

Since the brake disc (59) is made of a thin metal plate and has flexibility and is formed with a diameter larger than that of the protractor disc (58), the baseline brake mechanism (61) and the arbitrary angle brake mechanism (62) rotate. It can be provided at a position away from the center. Therefore, even if an error occurs in the distance between the fixed brake shoes (66) and (82), the bending of the brake disc (59) becomes large during braking, and the error is absorbed, and the braking force is hindered. Of course there is nothing to do,
Moreover, since the brake mechanisms (61) (62) are provided at positions apart from the center of rotation, the fixed brake shoes (66)
The required braking force can be obtained by a small pressure contact force between the brake disc (59) and the brake disc (59), so that the operation of the baseline brake lever (9) and the index lever (14) is performed. The force is reduced and sufficient braking force is maintained.

Further, a second index lever (83) is arranged above the index lever (74), and like the index lever (14) described in the conventional example, the connecting pin (1
Operate the index claw operation plate (18) via 6). The index pawl operating plate (18) is provided with a sub-rotating shaft (7
3) It penetrates through the lower end part of the scale mounting plate (53) and is inserted into the guide groove (53a), and the tip part (18a) projects upward from the hole (53b) of the scale mounting plate (53). The scale mounting plate (53) is fixed to the protractor plate (58) at a predetermined angle by being screwed into the claws (84) (84) of the (60).

[Advantages of the Invention] As described in detail in the above-described one embodiment, in this invention, the brake disc made of a metal plate used for the brake mechanism is formed to have a diameter larger than that of the protractor plate. It is provided so as to rotate integrally with a protractor board which is movably pivoted. Therefore, the baseline brake mechanism for braking the brake disc and the arbitrary angle brake mechanism are provided near the tip of the brake disc. Moreover, the baseline brake lever and the index lever are provided coaxially with the rotation axis of the grip portion, and the rotation of each lever is
Since the brake disc is braked through the brake mechanism having the respective driving / passive sector gears, the baseline brake lever and the index lever can be mounted as close to the grip portion as possible. Therefore, one-handed operation is possible, and since the braking portion is located away from the center of rotation, a sufficient braking force can be obtained with a small pressure contact force with the fixed brake shoe, and operability is improved. It will be.

[Brief description of drawings]

1 and 2 show an embodiment of the present invention, FIG. 1 is a vertical sectional view of a drawing head, and FIG. 2 is a partially cutaway plan view showing a driving sector gear and a passive sector gear of a baseline brake mechanism. FIG. 3 is a vertical sectional view showing a conventional drawing head. (50) …… Drafting head, (51) …… Support plate (52) …… Rotating shaft, (53) …… Scale mounting plate (58) …… Protractor plate (59) …… Brake disk (60) Latchet wheel (61) (62) Brake mechanism (63) (78) Brake, (64) (81) Center pin (65) (80) Brake shoe (66) (82) ) …… Fixed brake shoe (68) (77) …… Passive sector gear (69) (76) …… Drive sector gear (71) …… Baseline brake lever (74) …… Index lever

Claims (1)

(57) [Scope of utility model registration request] 1. A drafting head mounted on a carriage on a drawing board, wherein a scale mounting plate and a protractor are coaxially pivotally mounted on a supporting plate connected to the carriage, and the protractor is attached to the supporting plate. A reference line setting means for fixing at an arbitrary rotation angle, an arbitrary angle setting means for fixing the scale mounting plate at an arbitrary angle with respect to the protractor board, and a brake mechanism using a brake disc made of a thin metal plate. In the drafting head having the brake disc, which is used for the brake mechanism and is made of a thin metal plate, has a diameter larger than that of the protractor plate and is provided so as to be rotatable integrally with the protractor plate. A base line brake mechanism for braking the brake disc, and an arbitrary angle brake mechanism for braking the brake disc on the scale mounting plate near the tip of the brake disc. A base line brake lever for setting a reference line and an index lever for setting an arbitrary angle are loosely fitted to the rotating shaft of the scale mounting plate, and the base line brake lever and the base line brake lever are respectively connected via a power transmission mechanism having a main drive / passive sector gear. A drawing head characterized by connecting a base line brake mechanism provided on a support plate, and connecting the index lever and an arbitrary angle brake mechanism provided on a scale mounting plate to form a baseline brake mechanism and an arbitrary angle brake mechanism. Brake equipment.