JPS6329590Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an index device for a drawing machine that automatically fixes the scale mounting plate of the drawing machine at fixed angles by rotating the head section.

Conventionally, the index device of a drafting machine consists of an index gear fixed to a protractor mounted on the head, an index pawl rotatably mounted on the scale mounting plate with its base end as a fulcrum, and this index. An index pawl operation plate for engaging and disengaging the pawl with the index gear; an index lever protruding from the side of the grip portion of the head; one end connected to the index pawl operation plate, and the other end connected to the index pawl operation plate; and a connecting pin connected to the index lever.

The indexing device having the above configuration moves the index claw operation plate to the index by reciprocating the other end of the connecting pin by pushing the index lever and swinging the connecting pin within the rotation shaft. The index lever is moved in the opposite direction to the operating direction to rotate the index pawl in a direction in which it is disengaged from the index gear, thereby releasing the engagement state between the index pawl and the index gear. Then, by releasing the pushing operation of the index lever and rotating the grip section, the index pawl engages with the adjacent tooth groove of the index gear, and the protractor and scale mounting plate of the head section are again connected. becomes a fixed state. That is, by repeating the above-described operations, the scale mounting plate can be automatically fixed to the protractor at constant angular intervals.

In the conventional scale mounting apparatus, the index gear and index pawl are set so that the scale mounting plate can be fixed at 15 degree intervals, and when the scale mounting plate is rotated at 5 or 10 degree intervals to perform drawing work, and when drawing is performed at small angles such as when setting the positions of a large number of holes on the same circumference, when setting protrusions on the outer periphery of a disk shape, or when setting the drafting angle for castings, the scale mounting plate is not indexed, but the graduations on the protractor are aligned with the graduations on the vernier scale provided on the scale mounting plate, and the rotating shaft that moves with the rotation of the scale mounting plate with the scale mounting plate rotated 5 or 10 degrees is fixed by a fixing lever to a sub shaft that is integrally connected to the protractor.

Therefore, this invention solves the above conventional problems,
A drawing machine that eliminates the trouble of aligning the scales of the protractor and the vernier scale, and also allows the scale mounting plate to be automatically fixed to the protractor at 5 degree intervals. The purpose is to provide an indexing device.

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

FIG. 1 is a longitudinal sectional view of the head of a drawing machine to which the present invention is applied. A hollow rotation shaft 3 is disposed within the head portion 1 and is fixed to the grip portion 2 and is rotated along with the rotation operation of the grip portion 2. A sub-shaft 5, which integrally fixes the protractor board 4 with tightening screws 51, 51, is fitted onto the rotation shaft 3 so as to be rotatable with respect to the rotation shaft. There is. Although a detailed explanation will be omitted, the rotating shaft 3 is fixed to the secondary shaft 5 by tightening the angle fixing lever 6, and is tightened to the rotating shaft 3 as shown in FIG. 2A. The scale mounting plate 8, which is integrally fixed by the screws 7, can be fixed at a desired rotation angle.

Further, an index device 9 is disposed within the head portion 1 to automatically fix the scale mounting plate 8 to the protractor plate 4 at regular angular intervals by rotating the grip portion 2. There is.

This index device 9 includes an index gear 10 fixed to the protractor 4, and an index pawl 1 that engages and disengages with the index gear 10.
1, an index claw operating plate 12 serving as an index claw operating member for rotating the index claw 11, an index lever 13 disposed within the grip portion 2, and one end 14a connected to the operating plate 12. and the other end 14b is connected to the index lever 13.
It is composed of 4.

The index device 9 will be described in more detail with reference to FIGS. 2A and 2B. The index claw 11 is made of a substantially L-shaped plate, and the base end 11a is connected to the scale via a support pin 15. Mounting plate 8
The index pawl 11 is rotatable along the upper surface of the scale mounting plate 8 using the support pin 15 as a fulcrum. On the other hand, the tip end 11b of the index pawl 11 is a pawl portion 17 that engages with the tooth groove 16 of the index gear 10. The claw portion 17 is composed of a first claw portion 18 and a second claw portion 19 provided to protrude from the tip edge of the first claw portion 18.

The index claw 11 also has a long hole 22 into which an engagement pin 20 provided at the tip 12a of the index claw operation plate 12 is inserted and engaged through a hole 21 formed in the scale mounting plate 8. The reciprocating movement (second
The index pawl 11 is rotated by a movement in the left-right direction in the figure, thereby engaging and disengaging the index gear 10 and the index pawl 11.

Base end 12b of the index claw operation plate 12
and the hanging pin 23 provided on the scale mounting plate 8.
A tension spring 24 is disposed between the two, and the operating plate 12 is constantly pulled to the left in FIG. 2A by the tension of the tension spring 24. In addition, the operation plate 12 is attached to a scale mounting plate 8.
Screw insertion holes 25, 25 are formed in the form of elongated holes through which tightening screws 50, 50 are inserted, and the operation plate 12 is inserted into the insertion holes 25, 25 against the tension of the tension spring 24. Figure 2 A within the range of
It is movable in the left and right directions. In addition, one end 14 of a connecting pin 14 is inserted into an insertion hole 26 opened in the axial direction of the rotation shaft 3 in the operation plate 12.
An engagement hole 27 for engaging a is provided.

The insertion hole 26 is located in the middle of the connection pin 14.
A ring-shaped bulge 28 having a diameter substantially equal to or slightly smaller than the inner diameter of the connecting pin 14 is protruded, and the engagement between the bulge 28 and the insertion hole 26 serves as a pivot point for the connecting pin 14. It has come to consist of and,
The other end 14b of the connecting pin 14 is engaged with an engagement hole 29 formed in the index lever 13. Note that the index lever 13 has a knob portion 3 that serves as an operating portion of the index lever 13.
0 protrudes from the side of the grip portion 2 and is disposed within the grip portion 2.

On the other hand, as shown in FIG. 2B, the index gear 10 in this embodiment has tooth grooves 16, 16, . . . provided at intervals of 15 degrees, similar to the conventional gear.
The top portions 32, 32 of the tooth portions 31, 31, . . . are provided with engagement grooves 33, 33, .

Next, the operating state of the indexing device 9 having the above configuration will be explained.

First, while grasping the grip part 2 of the head part 1, push in the knob part 30 of the index lever 13, and move the index lever 13 as shown in FIG.
When the index lever 13 is operated forward in the direction of the middle arrow A, the other end 14b of the connecting pin 14 is also operated forward in the direction of the arrow A along with the operation of the index lever 13. Then, the index claw operation plate 12 is moved in the direction of arrow B in FIG. 2B against the tension of the tension spring 24, and the index claw 11 is moved in the direction of arrow C in FIG. 2A by the engagement pin 20. When the index pawl 11 is rotated, the index pawl 11 is disengaged from the index gear 10. That is, the scale mounting plate 8 is free with respect to the protractor board 4. and,
When the grip part 2 is rotated and the push-in operation of the knob part 30 of the index lever 13 is released, the connecting pin 14 moves back by the tension of the tension spring 24, and the index claw operation plate 12 is moved by the tension of the tension spring 24. It is rotated in the direction of arrow E in FIG. 2A by the tension, and the first claw portion 18 of the tip portion 11b is rotated by 15 of the index gear 10 as shown in FIG. 3A.
The second pawl portion 19 accommodates and engages with the tooth groove 16 for the 5 degree interval, and the second pawl portion 19 engages with the engagement groove 3 for the 5 degree interval formed in the tooth portion 31 of the index gear 10 as shown in FIG. 3B.
3. That is, by rotating the grip section 2 together with the above-described operation of the index device 9, the first claw section 18 of the index claw 11 is engaged with the tooth groove 16, and then the second claw section 19 is engaged with the above-mentioned tooth groove 16. The second claw portion 19 is engaged with the engagement groove 33 adjacent to the engagement groove 33, and then the first claw portion 18 is engaged with the tooth groove 16.
By engaging with the index claw 11
can be engaged with the index gear 10 at intervals of 5 degrees. That is, the scale mounting plate 8 can be automatically fixed to the protractor board 4 at intervals of 5 degrees.

As described above, according to the present invention, the index pawl can be engaged with the index gear every 5 degrees without increasing the number of parts in the conventional index device, and the scale mounting plate can be automatically connected to the protractor. It can be fixed at intervals of 5 degrees. Therefore, the trouble of matching the scale of the protractor with the scale of the vernier can be saved, leading to faster drafting work.

In the present invention, since the state of engagement between the respective pawls of the index pawl and the index gear with the tooth grooves or engagement grooves can be determined by the amount of operation of the index pawl, the index pawl and the index gear can be indexed at intervals of 15 degrees and every 5 degrees. It becomes possible to use them properly.

[Brief explanation of the drawing]

1 to 3 are views showing one embodiment of the present invention, in which FIG. 1 is a longitudinal cross-sectional view of the head of the drawing machine, FIG. 2A is an exploded perspective view showing the indexing device, and FIG. B is a partially omitted enlarged plan view of the index gear, and FIGS. 3A and 3B are partially omitted enlarged plan views showing the engaged state of the index gear and the index pawl. 9... Index device, 10... Index gear, 11... Index claw, 12... Index claw operation plate, 13... Index lever, 14... Connection pin, 16... Tooth groove, 18...
First claw part, 19... Second claw part, 33... Engagement groove.

Claims (1)

[Scope of utility model registration request] By connecting one end of the connecting pin to the index claw operating member and having the other end of the connecting pin having a fulcrum in the middle to an index lever, and by operating the index lever, the connecting pin is swung about the fulcrum. In an index device of a drafting machine in which an index operation is performed by releasing the engagement state between an index pawl and an index gear, a first pawl portion is provided at the tip of the index pawl, and a tip edge of the first pawl portion is provided. A second pawl portion is provided on the index gear, and tooth grooves in which the first pawl portion is accommodated and engaged are carved at 15 degree intervals on the index gear, and the second pawl portion is engaged between these tooth grooves. An indexing device for a drafting machine in which engagement grooves are cut at 5 degree intervals to enable the index pawl to engage with the index gear at 5 degree intervals.