JPH0432320Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to the head of a universal parallel ruler.

In conventional parallel ruler heads, the indexing mechanism is located between the protractor and the scale mounting plate. The protractor is fixed to the head support base via a fixing device, but when a shock load is applied to the protractor from the scale mounting plate side via the index mechanism, the protractor is fixed to the head support base. The board moves slightly. If the protractor moves slightly, the zero degree direction of the horizontal straightedge will no longer match the primary or secondary baseline set by the flexible parallel ruler, resulting in a drafting error. did.

The object of the present invention is to provide a head of a universal parallel ruler which eliminates the above-mentioned defects.

The configuration of the present invention will be described in detail below based on embodiments shown in the accompanying drawings.

Reference numeral 1 denotes a drawing board, which is supported by a tiltable drawing board (not shown). 3 is a horizontal rail fixed to the drawing board, to which a horizontal cursor 5 is movably connected. Reference numeral 7 denotes a vertical rail, the upper end of which is connected to the horizontal cursor 5, and the lower end of the vertical rail 7 is placed on the drawing board 1 via tail rollers 9 so as to be freely movable. A vertical cursor 11 is movably attached to the vertical rail 7, and a head 17 is connected to this via a known link mechanism 15.

Next, the internal structure of the head 17 will be explained with reference to FIGS. 2 to 4.

2 is a head support base, one of which is connected to the vertical cursor 11 via the link mechanism 15 mentioned above. 8 has index recesses 10 every 15 degrees
This is an index ring formed with a 3D index ring, which is fixed to the lower surface of the base 2. A tubular main shaft 14 is rotatably fitted into the inner circumferential surface of the tubular portion 2a of the base 2 via a tubular body 12, and a tubular body 16 is fitted and fixed onto the outer circumferential surface of the tubular portion 2a. 18 is a cylindrical body rotatably supported by the tube 2a, and a spiral spring 20 is disposed between the inner peripheral surface of the cylindrical body 18 and the outer peripheral surface of the tube 16. One end of the spring 20 is engaged with a hole 22 in the tube body 18, and the other end of the spring 20 is engaged with a hole (not shown) provided in the tube body 16. Reference numeral 24 denotes a protractor which is rotatably fitted onto the outer peripheral surface of the base 2, and has a minute scale (not shown) engraved on the upper surface of the outer peripheral surface. 26 is a protractor plate fixing spring;
One end is fixed to the base 2, and the other end faces the outer peripheral surface of the tube portion of the protractor board 24. Reference numeral 28 denotes a protractor fixing lever, which is rotatably supported by a shaft 30 on the base 2. When the lever 28 is horizontally tilted, the eccentric enlarged portion of the eccentric cam portion 28a formed at the tip of the lever 28 engages the spring 2.
6 is pressed, and the other end of the spring 26 is brought into pressure contact with the outer peripheral surface of the tube portion of the protractor board 24 due to this pressing force. Reference numeral 32 denotes a stopper protruding from the cylindrical body 18, and a stopper 34 corresponds to the stopper.
is provided protrudingly from the base 2. A handle 36 is fixed to a mounting plate 38 with bolts, and the mounting plate 38 is connected to the main shaft 14 with a nut.
is fixed at the top of the. A scale mounting plate 40 is fixed to the lower end flange of the main shaft 14 with screws. A horizontal straightedge 4 is attached to the scale mounting plate 40.
2 and a vertical straightedge 44 are fixed. Reference numeral 46 designates a transmission plate, one end of which is connected to the lower end of the conical rod 48, and a shaft 50 protruding from the other end of the transmission plate 46. Reference numeral 54 denotes a swinging arm whose one end is rotatably supported by a shaft 52 on the scale mounting plate 40, a long hole is formed in the middle part of this swinging arm, and a claw 54a is formed at the other end of the swinging arm 54. has been done. The shaft 50 is
It passes through an elongated hole provided in the scale mounting plate 40 and is fitted into the elongated hole of the swing arm 54. 5
Reference numeral 6 denotes an angle indicator plate on which an index and a scale for reading minute angles are formed, and is fixed to the scale mounting plate 40 via a stand. 58 is a baseline vernier plate fixed to the base 2, on which an index and an angle scale are formed. 60 is a bottom plate fixed to the scale mounting plate 40, and a transparent cover 62 is attached to this. A shaft 64 is rotatably fitted into a groove 66 formed in the scale mounting plate 40, and its outer peripheral surface faces the outer peripheral surface of the protractor plate 24 so as to be press-fittable.

A molding 68 is fixed to the shaft body 64, and a portion of the molding 68 is exposed to the outside through a hole formed at the joint between the cover 62 and the bottom plate 60. 70
is a lever rotatably supported by a shaft 72 on a bracket fixed to the handle 36, and a stopper portion 70a of this lever has a protrusion 18a formed on the cylindrical body 18, which is connected to the spring 20 in FIG. , are in elastic contact due to the elasticity in the counterclockwise direction of rotation of the hour hand. A thrust ball bearing 74 is fitted into the main shaft 14, and its lower seat plate 74a abuts the upper end of the base tube portion 2a, and the lower surface of the serration shaft 76 is placed on the upper seat plate 74b. A threaded portion formed on the inner diameter portion of the serration shaft 76 is screwed into a threaded portion formed on the outer periphery of the main shaft 14. Serration teeth formed on the outer circumference of the serration shaft 76 mesh with serration teeth formed on the inner diameter of the lever 78 . The lever 78
A long groove is formed on one side of the index operating lever 80, and a shaft 82 protruding from the lower surface of the index operating lever 80 is fitted into the long groove. One end of the lever 80 is connected to the upper end of the conical rod 48. A locking surface 80a is formed on the lever 80, and a stopper shaft 36a is formed on the handle 36 in correspondence with the locking surface. A wave washer (not shown) is inserted into the shaft 82 and positioned between the levers 80 and 78.

Next, the operation of this embodiment will be explained.

With the claw 54a of the swinging arm 54 fitted into the predetermined index recess 10, the horizontal straightedge 42
is set to be exactly parallel to the horizontal rail 4. In this state, the angle indicator plate 56
The index indicates the zero degree on the minute scale of the protractor board 24,
The indicator on the baseline vernier plate 58 also points to zero degrees on the protractor scale. In this state, the straight line drawn on the paper by the horizontal straightedge 42 is called a primary baseline. When the lever 80 is pushed to the left in FIG. 2 and the conical rod 48 is swung in the counterclockwise direction of rotation of the hour hand around its intermediate bulge, the transmission plate 46
moves to the right in FIG. As a result, the swinging arm 54 swings about the shaft 52 in the direction of rotation of the hour hand in FIG. 4, and the claw 54a separates from the index recess 10 of the index ring 8. In this state, by rotating the handle 36, the horizontal straightedge 42 can be set at a desired angle with respect to the primary base line. For example, horizontal straightedge 42 is 35
When it is desired to set the degree to zero degrees, first rotate the lever 80 in the direction of rotation of the hour hand in FIG. As a result, the lever 78 rotates in conjunction with the lever 78, and the serration shaft 76 rotates. When the serration shaft 76 rotates, the threaded portion of the serration shaft 76 and the main shaft 1
The serration shaft 76 rotates around the main shaft 14 with the upper seat plate 74b as a fulcrum by the threaded guiding action of the threaded portion 4.
This pulling force causes the lower end flange of the main shaft 14 to pass through the lower end flange of the tube body 12 to the base 2.
, and the main shaft 14 is fixed to the base 2 side. Next, when one of the degree fixing levers 28 is lifted to release the pressing force of the eccentric cam 28a against the spring plate 26, the pressing force of the spring plate 26 against the degree board 24 is released. Next, push the molding 68 and press the shaft 6.
4 to the outer peripheral surface of the protractor board 24, press the molding 68.
When rotated, the protractor 24 rotates around the outer peripheral surface of the base 2.

When the zero degree of the minute scale is positioned with respect to the indicator on the angle indicator plate 56, the rotation of the degree dial 24 is stopped, and the lever 28 is pushed down to fix the degree disk 24 to the base 2. In this state, if a line is drawn along the horizontal straight edge 42, this line will become a secondary baseline having an angle of 35 degrees with respect to the primary baseline.
When the lever 80 is swung to its original position in the counterclockwise direction of rotation in FIG. Can be set at any angle. The angle of the secondary baseline with respect to the primary baseline can be determined by looking at the angle that the indicator on the baseline vernier plate 58 points to with respect to the degree scale of the protractor board 24.

As described above, in the present invention, since the index ring is fixedly installed on the head support base side, there is no possibility that the index ring will shift in the rotational direction with respect to the head support base, and therefore there is no possibility that the index ring will deviate from the primary base line. There is an advantage in that the secondary base line can be set at a desired angle without any distortion.

[Brief explanation of the drawing]

The figures show preferred embodiments of the present invention, with Figure 1 being a plan view, Figure 2 being a sectional view of the head, and Figure 3 being A-A.
4 is a plan view, and FIG. 5 is a sectional view. 2...Base, 8...Index ring, 1
4... Main shaft, 20... Wind-up spring, 24...
Protractor board, 36...handle, 40...scale mounting plate, 4244...straight ruler.

Claims (1)

[Scope of utility model registration request] head support base 2 and head support base 2
a main shaft 14 rotatably supported by the main shaft 14;
a scale mounting plate 40 attached to the head support base 2; a protractor plate 24 attached to the head support base 2; and an angle indicator plate attached to the scale plate 40 so as to be movable along the protractor plate 24. 56, the index ring 8 is fixed to the head support base 2, and the swinging arm 54 is placed on the scale mounting plate 40 side.
Index recess 1 of the index ring 8
1. A head of a universal parallel ruler, characterized in that the head is attached so as to be engageable and disengageable with respect to the head support base 2.