JPH0445357B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a ruler guide device in a parallel ruler device, and is particularly characterized in that the frictional force of the ruler guide portion is reduced by utilizing the attractive force of a magnet.

This device utilizes the repulsive force of a magnet to bias the vertical cursor supporting both ends of the ruler in the floating direction relative to the vertical rail, thereby reducing the running friction of the vertical cursor along the vertical rail. It has already been developed by the applicant. When the repulsive force of a magnet is used to reduce the running friction force of a vertical cursor, the following defects exist. In other words, the drawing board to which this type of rail is attached can generally be set at any angle of inclination within the range of approximately horizontal to the floor and approximately 80° in the direction of standing. is supported on a drafting table. Therefore, when the drawing board is horizontal to the floor surface, the load applied to the vertical rail side in the direction perpendicular to the drawing surface of the vertical cursor is the largest.
When the drawing board is tilted at approximately 80 degrees with respect to the floor surface, the load applied to the vertical rail in the direction perpendicular to the drawing surface of the vertical cursor is the smallest.
This means that when the load on the vertical cursor side due to the weight of the ruler and vertical cursor is supported by the repulsive force between the magnet placed on the vertical rail side and the opposing magnet placed on the vertical cursor side, As the inclination angle of the drawing board changes, the opposing gap between the magnets changes significantly. This means that the distance between the lower surface of the straightedge installed between the vertical cursors and the drawing surface changes greatly.
This is unfavorable for precise line drawing work.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to eliminate the above-mentioned defects by reducing vertical movement changes of the vertical cursor in a direction perpendicular to the drawing surface due to changes in the load of the vertical cursor. The configuration of the present invention will be described in detail below based on embodiments shown in the accompanying drawings.

Reference numeral 2 denotes a drawing board, which is fixed to a drawing board support frame of a known drafting table so that the inclination angle can be set at a desired angle between a horizontal state and a substantially upright state. Reference numerals 4 and 6 denote vertical rails fixed to both sides of the drawing board 2 by vise-type fixtures, and a weight insertion space 8 and a groove are formed in the vertical rails 4 and 6 over the entire length in the longitudinal direction. has been done. Magnets 10 and 10' made of four magnetic rubbers are fitted and fixed in parallel to each other through iron plates 12 so that different polarities are adjacent to each other in the grooves on the outside of the vertical rails 4 and 6 over the entire length thereof. , Four magnetic pole tracks are formed by the magnetic rubber on the outer surface of each of the vertical rails 4 and 6 perpendicular to the drawing surface in the order of NSNS from the top in the drawing. There are 2 grooves in the grooves on both sides of each inner wall surface of the vertical rails 4 and 6.
Magnets 14 and 16 made of book magnetic rubber are fitted and fixed so that different polarities are adjacent to each other. A pair of magnetic pole tracks are formed at a predetermined interval. Numeral 18 consists of four magnetic rubbers that are fitted and fixed in parallel through iron plates 22 so that different polarities are adjacent to each other in grooves formed on the inner surface of the vertical part perpendicular to the drawing surface of the vertical cursor 20. The magnet 18 has a different polarity facing the magnet 10, and the vertical cursor 2 is drawn by an attractive magnet acting between the magnets 18 and 10.
A downward load perpendicular to the two planes of the drawing board 0 is supported. Reference numeral 24 denotes two guide rollers for preventing lateral vibration that are rotatably supported on the lower horizontal portion of the vertical cursor 20, and the surfaces of these guide rollers correspond to a pair of vertical rail surfaces formed on the bottom wall of the vertical rail 4. It is in rotatable contact with one of the rail surfaces. The other vertical rail surface 2 of the vertical rail surfaces
8, one guide roller (not shown) for preventing lateral vibration, which is rotatably supported by the lower horizontal portion of the vertical cursor 20, is rotatably abutted.

One end of each of wire ropes 30, 32 is connected to the front and rear of the upper horizontal portion of the vertical cursor 20, and the wire ropes 30, 32 are connected to rope pulleys 34, 36 rotatably disposed at both ends of the vertical rail 4. It's being passed around. 38 is the weight insertion space 8
This is a balance weight disposed inside, and the other ends of the wire ropes 30, 32 are connected to the front and rear ends of this balance weight. Reference numerals 40 and 42 designate magnets each consisting of a pair of magnetic rubbers fixed to both sides of the lower part of the balance weight 38, the magnet 40 having a different polarity facing the magnet 14, and the magnet 42 facing the magnet 16. The opposite polar surface is opposite to. The balance weight 38 floats a predetermined distance from the bottom surface of the weight insertion space 8 due to the attractive magnetic force acting between the magnets 40 and 14 and between 42 and 16. Reference numeral 44 designates a pair of guide rollers for preventing lateral vibration that are rotatably supported on the lower surface of the balance weight 38, and these surfaces are formed along the entire length of the bottom wall of the vertical rail 4 in its longitudinal direction. A balance weight 38 is rotatably abutted on one of a pair of vertical rail surfaces, and a balance weight 38 is positioned between the pair of guide rollers and rotates on the lower surface of the balance weight 38 on the other surface of the vertical rail surface. The surfaces of freely supported guide rollers (not shown) are in contact with each other. 46 is a ruler mounting plate formed integrally with the vertical cursor 20, and between this and a ruler mounting plate 48 formed integrally with the vertical cursor 50 movably arranged along the vertical rail 6. horizontal ruler 5
2 is removably hung. Said horizontal ruler 52
As shown in FIG. 3, there are mounting screws 54 near both ends of the
is fixedly installed, a washer 56 is fitted onto the mounting screw 54, and a molding 58 is screwed together. 60 is a cap screw screwed onto the upper end of the mounting screw 54 to prevent the molding from coming off. Bring both ends of the horizontal ruler 52 to the mounting plates 46, 48, insert the mounting screws 54 fully into the vertical holes 62, 64 of the mounting plates 46, 48,
Thereafter, the molding 58 is rotated in the tightening direction to fix both ends of the horizontal ruler 52 to the ruler mounting plates 46, 48. The lower surface of the horizontal ruler 52 is set to be slightly raised relative to the two surfaces of the drawing board. A balance weight is also arranged on the vertical rail 6, and the structure of the vertical cursor 50 and the vertical rail 6 is the same as that shown in FIG. In this embodiment, the strength of the attractive force between the magnets 10 and 18 on the vertical rail 4 and the vertical cursor 20 side, and the strength of the attractive force between the vertical rail 6 and the magnet 1 on the vertical cursor 50 side.
The strength of the attraction force between 0' and 18' is approximately the same. Also, the total weight of the horizontal ruler 52 and the vertical cursors 20, 50, and the balance weight 38 on the vertical rails 4, 6 side.
The total weight of is set to be the same.

Next, the operation of this embodiment will be explained.

Normally, this type of parallel ruler device is used with the drawing board 2 standing vertically. When the drawing board 2 is raised up, the horizontal ruler 52 tries to fall along the drawing board 2 surface, but this falling force is canceled out by the falling force of the two balance weights 38, and the horizontal ruler 52
Even if you release your hand, the horizontal ruler 52 remains at the desired position. When force is applied to the horizontal ruler 52 or the vertical cursors 20, 50 in the vertical direction in FIG. The two balance weights 38 move while being guided by the rails 26 and 28, and in conjunction with the vertical cursors 20 and 50, move on the vertical rail surfaces of the vertical rails 4 and 6 in the opposite direction to the vertical cursors 20 and 50. You will be guided and move in a floating state. As mentioned above, the vertical cursor 20,5
0 and the balance weight 38 are floating due to magnetic force with respect to the traveling path, so the horizontal ruler 52
The movement is carried out smoothly with extremely light manual operation force. In addition, when the inclination angle of the drawing board 2 is changed from, for example, horizontal to the floor surface to an inclination angle of approximately 80°, the total weight of the horizontal ruler 52 with respect to the vertical rail 4 and the drawing board 2 surface The load in the vertical direction changes in the direction of relief. However, due to this load change, the magnet 18 slightly changes in the upward direction relative to the magnet 10, but the upper end U of the magnet 18
It does not move above the upper end V of. magnet 1
No matter how large the load change is, magnet 8 is stabilized when the level of its upper end U is slightly lower than the upper end V of magnet 18. This means that even if a magnet with a much stronger magnetic force than the optimum magnetic force for supporting the total weight of the horizontal ruler 52 is used, the ruler 52 will not float too high relative to the two surfaces of the drawing board. That is,
As long as the magnet has a predetermined magnetic force or more, a considerable range of magnet selection is allowed.

As described above, in the present invention, both ends of the horizontal ruler are biased in the direction of floating with respect to the vertical rail by the attractive force of the magnet, so even if the load on the horizontal ruler side against the vertical rail changes, the horizontal ruler remains Changes in the height level relative to the drawing surface can be reduced, and accuracy is not required for the magnitude of the magnetic force of the magnet, so there is no need to use a magnet suitable for the parallel ruler model. This has the advantage that quality control is easy.

[Brief explanation of drawings]

The drawings show a preferred embodiment of the present invention, in which Fig. 1 is an overall plan view, Fig. 2 is a side sectional view of the main part, Fig. 3 is a partial sectional view, and Fig. 4 is a side sectional view. . 2... Drawing board, 4, 6... Vertical rail, 8... Weight insertion space, 10... Magnet, 12... Steel plate,
14, 16...Magnet, 18...Magnet, 20...Vertical cursor, 22...Iron plate, 24...Guide roller,
26...Rail surface, 52...Horizontal ruler, 50...Vertical cursor.

Claims (1)

[Claims] 1. A parallel ruler device consisting of vertical rails fixed to both sides of a drawing board, vertical cursors movably arranged along each of the vertical rails, and a horizontal ruler suspended between the vertical cursors. In the ruler guide device, a magnet is disposed on each outer portion of the vertical rail perpendicular to the drawing surface, extending over the entire length of each outer portion in the longitudinal direction, and each magnet has a different polarity. Magnets are disposed on each side of the vertical cursor so as to face each other with a predetermined interval, and the drawing on the vertical cursor side is caused by the attractive magnetic force acting between the magnets having different polarities facing each other. A ruler guide device for a parallel ruler device, characterized in that it supports a downward load in a direction perpendicular to a plate surface.