JPH0114469Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a head support device for a universal parallel ruler.

Conventionally, devices of this type have been used that support the load of the head and scale using spring elasticity. As expressed by Wcosθ, the inclination angle θ with respect to the horizontal changes greatly from W to O while the inclination angle θ changes from 0° to 90°. It was necessary to change the spring elasticity.

Therefore, the present invention provides a head support device for a universal parallel ruler that can support the head in a raised position relative to the drawing surface regardless of the inclination angle of the drawing board, and can guide its vertical movement. This is what I am trying to do.

The device of the present invention will be explained in detail with reference to the embodiments shown below. 1 is a cursor side link fixed to a cursor plate 3 that moves along a vertical rail 2; 4 is a head support link that supports the head; both links 1 and 4 are connected to the upper link 5 by pivots having axes P ₁ and P ₂ , respectively. The cursor side link 1 is provided with a swing member 7 having a support shaft 6 at the same axis position as the P ₁ , and is rotatable by a support shaft 8 at the free end of the swing member 7. A tension member 9 on the cursor side is provided. On the other hand, the head support link 4 has a tension member 11 on the head side centered around a support shaft 10 having the same axis position as _P2 .
is rotatably provided, and the free end of the tension member 11 is bendably connected to the end of the tension member 9 by a bending shaft 12. A cam surface 13 is integrally provided at the end of the tension member 9 facing the head support link 4, and a roller 14 provided at the lower part of the head support link 4 is in contact with this cam surface 13. Further, the cursor-side link 1 is provided with an adjustment screw member 15 on the wall surface facing the swinging member 7, which regulates the range of swinging of the swinging member 7 toward the cursor side. Head support link 4 with members 9 and 11
The structure is such that the height of the raised position can be adjusted.
On the other hand, a bending member 16 is provided on the upper link 5 so as to project toward the tension members 9 and 11 so as to be height adjustable.

In the embodiment configured as described above, when the head section and the scale are in contact with the drawing board surface as shown in FIG. The pressing force of the roller 14 centered on the axis _P2 acts to push the tension members 9, 11 upwards around the bending shaft 12, and as the head portion is lifted as it is, the second As shown in the figure, the support shafts 8, 10 and the bending shaft 12 are located in a straight line, the tension members 9, 1
In this tensioned state, the bending member 16 of the upper link 5 comes into contact with the upper surface of the tensioning member 9, and even if you release your hand from the head, the load on the head and scale remains on the tensioning member 9. , 11. Note that if the protruding length of the bending member 16 is too large, the tension members 9 and 11 will not be able to reach the tension state, so when the head is released, the load will cause the tension members to fall in the direction of the drawing board. That will happen. Further, it is clearly understood from FIG. 2 that the height of the raised position of the head portion can be adjusted by adjusting the protruding length of the adjusting screw member 15. Furthermore, the cam surface 13 of the tension member 9
constitutes a cam guide mechanism that maintains the posture of the head portion and the scale during the rising process from the contact position shown in FIG. 1 relative to the drawing surface to the raised position shown in FIG. 2. On the other hand, if the head part is further lifted in the tensioned state shown in the second figure, it will come into contact with the bending actuating member 16 and the tension members 9 and 11 will bend around the bending shaft 12, so that they will continue to descend as shown in the first figure. It can be moved to the desired position. Furthermore, if the head portion is continued to be lifted, the swinging member 7 will swing away from the adjustment screw member 15, and the upper link 5 and the head support link 4 will be moved to the upright state as shown by the broken line in FIG. I can do it.

As described above, according to the head support device of the universal parallel ruler according to the present invention, in order to move the head for scale operation up and down substantially parallel to the drawing surface, the cursor side link and the head support link are connected. In a flexible parallel ruler connected by a parallel motion mechanism having an upper link and a cam guide mechanism, a cursor-side tension member is rotatably provided at the bottom of the cursor-side link, and the cursor-side tension member is rotatably mounted at the top of the head support link. A tension member on the head side is freely provided, and the tension members on the cursor side and the head side are connected to each other so as to be flexible by a bending shaft, and the cam guide mechanism is attached to the tension member on the cursor side with a cam surface. and a contact portion that contacts the cam surface at the lower part of the head support link, and a bending actuating member that contacts the upper surface of the tension member when the tension member is in the tensioned state is connected to the upper link. Since the tension member is configured to protrude from the lower side, the cam guide mechanism allows the tension member, which has been maintained in a bent state at the lowered position of the head portion, to be lifted upward as the head portion rises and to be bent. The tensioning member is loosened, the tensioning member is in a tensioned state at the raised position, and the bending member is brought into contact with the upper surface of the tensioning member.
This has the effect of maintaining the tensioned state of the tension member and supporting the head section regardless of the magnitude of the load, and when the head section is further lifted upward using the bending member as a fulcrum, the tension member will bend. This has the effect of moving the head part to the lowered position, while the cam guide mechanism that constitutes the vertical parallel movement mechanism of the head part with respect to the drawing surface is provided with a cam surface on the tension member on the cursor side. Since the lower part of the head support link is provided with a contact part that contacts the cam surface, the tension member also serves as a cam guide mechanism, and there is no need to provide the conventional structure of the lower link parallel to the upper link. , which has the effect of achieving structural simplification.

[Brief explanation of the drawing]

FIG. 1 is a partially longitudinally sectional front view showing a main part of an embodiment of the device of the present invention, and FIG. 2 is a front view showing its operating state. 1...Cursor side link, 4...Head support link, 5...Upper link, 9, 11...Tension member, 13...Cam surface (cam guide mechanism).

Claims (1)

[Scope of utility model registration request] A flexible parallel ruler in which a cursor side link and a head support link are connected by a parallel movement mechanism having an upper link and a cam guide mechanism in order to move the head part for scale operation up and down approximately parallel to the drawing surface. A cursor-side tensioning member is rotatably provided at the bottom of the cursor-side link, and a head-side tensioning member is rotatably provided at the top of the head support link, and the cursor-side and head-side tensioning members are While the members are connected to each other in a flexible manner by a bending shaft, the cam guide mechanism is provided with a cam surface on the cursor side extension member, and a contact portion that abuts the cam surface on the lower part of the head support link. What is claimed is: 1. A head support device for a universal parallel ruler, comprising: a bending actuating member protruding from the lower side of the upper link;