JPH0356396Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a head support device that can support a head and a scale of a universal parallel ruler in a height-adjustable manner above the drawing surface.

Conventionally, as a head support device for a universal parallel ruler, one is known that uses a spring member to press the head upward, but in this case, the pressing force of the spring member is such that when the head comes into close contact with the drawing surface It becomes weaker as the head moves upward, so that when the angle of inclination of the drawing board becomes large with respect to the horizontal, there is a drawback that the head does not come into close contact with the drawing surface.

Furthermore, Japanese Utility Model Publication No. 50-37875 discloses a device in which the spring member is configured as a constant force spring so that the spring elasticity does not decrease as the scale and head portion rise. Theoretically, the same pushing up force will be applied to the head support when the head is floating and when it is in close contact with the drawing surface, so if the spring force is set strong, the head will float. There is a problem with the top remaining stuck.

As a conventional device to eliminate this drawback, for example, as described in Japanese Patent Application Laid-Open No. 55-126497, a cam member having an inclination such that the head portion moves upward and an inclination such that the head portion moves downward is used. There is a known structure in which a push member and a spring member are used to apply push-up or push-down elasticity, but not only is the structure complicated, but since there is switching between push-up and push-down, it is difficult to smoothly move the head up and down. There was a problem of lack of quality.

Furthermore, in Japanese Patent Application Laid-Open No. 54-10025, a head support link is connected to a cursor side link by an upper link and a lower link to a quadrilateral link mechanism, and the head support link is connected to the upper link by its own weight. For example, a cam surface formed with a special curvature on the center upper surface of the lower link comes into contact with a roller provided at the center lower part of the upper link to act as a head supporting force to reduce the downward rotational moment. In addition, a structure in which the intermediate portions of the upper link and the lower link are connected by a link piece and acts as a head supporting force through the link piece is shown, but the link structure for supporting the head is complicated, Further, there were problems such as difficulty in adjusting the head supporting force.

Further, as described in Japanese Utility Model Application Publication No. 58-60495, the applicant has provided a cursor side link via a parallel movement mechanism so as to move the head portion and scale up and down approximately parallel to the drawing surface. The head support link is connected to the cursor side link and the head support link, and one end is connected to one link so as to be swingable with one end as a swing fulcrum, and the other end is pushed up to the other link. A support lever is provided which is brought into contact with the support lever, and between the other end of the support lever and the link on which the support lever is swingably provided,
We have proposed a head part support device for a universal parallel ruler in which the support lever is provided with a tension spring means that applies a push-up force that increases as the head part and the scale move upward. The upper limit stopper is not only a simple upper limit regulating stopper that cannot vertically adjust the upper limit position of the head and scale, but also a tension spring installed along the support lever because it is configured to contact the middle part of the support lever. In order to prevent the upper limit stopper from coming into contact with the tension spring means, it is necessary to provide the tension spring means at a distance from the support lever, and the tension spring elasticity increases by the distance of the tension spring means. There is a problem in that the load is applied as an uneven load to the swinging fulcrum of the support lever.

Therefore, the present invention connects the head support link to the cursor side link via a parallel movement mechanism so that the head part and scale move up and down approximately parallel to the drawing surface, and the cursor side link and the head A support lever is provided between the support link and the support lever, which is swingably connected to one link using one end as a swing fulcrum and abuts the other link with its tip as a push-up part. , a flexible parallel ruler in which a tension spring means is provided on the support lever between the support lever and the link that is swingably provided to apply a push-up force that increases as the head portion and the scale move upward; In the head support device, an extending portion is provided at one end of the support lever along the one link, and the one link is provided with an extending portion of the support lever so as to contact the extending portion of the support lever. While providing a height adjustment stopper means for vertically variably adjusting the upper limit swing position of the push-up part,
A guide pin is provided at the tip of the support lever, and the other link includes an engaging portion that removably engages with the guide pin to interlock the support lever, and a guide pin detached from the engaging portion. The present invention provides a head support device for a universal parallel ruler, which is provided with an arm guide that is slidably fitted into the arm guide and has a guide hole that guides the upward rotation of the head and the scale.

The device of the present invention will be described in detail with reference to the embodiments shown below. Reference numeral 1 denotes a cursor side link, which is integrally fixed onto a cursor plate 2 with a fixing screw or the like.
The cursor plate 2 is movably guided on a guide rail 3 of a vertical rail 4 by running rollers 5. 6
A head support link integrally supports the head portion 7, and is connected to the cursor side link 1 by a parallel movement mechanism so that it can move up and down substantially parallel to the cursor side link 1. In the case of the embodiment, the upper parts of both the links 1 and 6 are connected to the upper link 8 by pivots 9 and 9a, and the lower parts thereof are connected to the upper link 8 by pivots 11 and 1 as shown in the second figure.
2 to the lower link 10, and each pivot 9 of the upper link 8 and lower link 10
9a, 11, and 12 are arranged so as to be located at corner points of a substantially parallelogram to constitute a parallel motion mechanism. In addition, in the case of the example, the lower link 1
The pivot shaft 11 of the 0 cursor side link 1 is provided at the swinging end of a swinging member 13 that swings about a substantially coaxial position with the pivot 9 of the upper link 8, and is provided at the bottom end of the swinging member 13. The parallel movement can be adjusted by the adjusting screw 14, and the head support link 6 can be turned out of parallel and rotated significantly upward about the pivot shaft 9a.

Here, in the case of the embodiment of the head support device according to the present invention, a support lever 15 is swingably provided on the cursor side link 1 with a support shaft 16 as a swing fulcrum, and a roller 17 is provided at the tip of the support lever 15 as a push-up part. It is provided. The roller 17 is the lower surface 6 of the head support link 6.
It is in contact with a.

The present invention consists of a support lever 15 and a cursor side link 1.
The present invention is characterized in that a tension spring means is provided between the support lever and the support lever to apply a push-up force that increases as the head portion and the scale move upward.

That is, the spring-loaded shaft 1 is attached to the tip of the support lever 15.
8 is provided, and the cursor side link 1
A spring hanging shaft 19 is provided, and a push-up spring member 20 imparted with tensile elasticity is stretched between these spring hanging shafts 18 and 19 to serve as a tension spring means.

For convenience of explanation, a support shaft 16 is attached to the support lever 15.
and the line connecting the spring hanging shaft 18 and the spring hanging shaft 18 and 1.
9, that is, the line connecting the support shaft 16 of the support lever and the spring hanging shaft 18, which is the point where the push-up spring member 20 exerts a tensile force on the support lever 15, and the tension direction of the push-up spring member 20. The angle formed by the line connecting support shafts 18 and 19, which is the point of application of the tensile force of the push-up spring member 20 that determines , is defined as the tension angle by the push-up spring member 20 that pulls the support lever in the push-up direction.

In the case of the embodiment, the push-up spring member 20 has an angle at which its tension angle is horizontal to the line connecting the swinging shaft 16 of the support lever 15 and the spring hanging shaft 18 when the head portion and scale are in contact with the drawing board surface. The tension angle is increased as the head portion and the scale float above the drawing board, and the head portion and the scale are configured to be supported by the increased spring acting force at the floating position. It has been done.

To explain this point with reference to FIG. 8, the support lever 15 rotates at an angle θ around the support shaft 16, and the push-up spring member 20 stretched between the spring hanging shafts 18 and 19 applies the tensile elasticity F at the tension angle α. When applied to the support lever 15, the upward rotational moment M acting on the support lever 15 is generated by the tensile elasticity F from the support shaft 16.
If the length of the perpendicular line drawn to is a, then M=Fa, and a is the length of the support shaft 16 and the spring-loaded shaft 18, a=Lsinα, so the support lever 15
The rotational moment M in the push-up direction applied to is M=FLsinα. Also, as is clear from the figure, the tensile angle α
increases with the upward rotation angle θ of the support lever 15.

Therefore, when the tension angle α=0, M=0,
For example, when α=5°, M=0.09FL, when α=10°, M=0.17FL, when α=15°, M=0.26FL, α=
As is clear from the fact that M=0.5FL at 30°, the upward force exerted by the upward force by the upward spring member 20 increases as the support lever 15 swings upward along the sine curve. Further, although the length of the spring member 20 decreases as the tension angle α increases, the rate of decrease is small compared to the length of the spring member 20 to which tensile elasticity is applied.
The decrease in the tensile force that affects the upward force, which increases significantly with the sine curve, can be set within a negligible range.

The gist of the present invention is that the support lever is provided with a tension spring means that applies a push-up force that increases as the head portion and the scale move upward. This is realized by a configuration in which the tension angle α by the tensioning spring member 20 increases as the head portion and the scale move upward from the drawing surface, and the tension angle α
Whether or not the head portion and the scale increase as they move upward from the drawing surface is determined by the eighth point.
In the figure, once the support shaft 16 of the support lever 15 and the application points 18 and 19 of the push-up spring member 20 are determined, the tension angle α can also be uniformly determined geometrically as the rotation angle θ of the support lever 15 changes. This can be clearly recognized from the following.

On the other hand, in the present invention, an extending portion is provided at one end of the support lever along one link having a spindle of the support lever, and the one link is provided with an extending portion that corresponds to the extending portion of the support lever. The main feature of the present invention is to provide a height adjustment stopper means for vertically variably regulating the upper limit swing position of the push-up portion of the support lever.

That is, in the present invention, in the case of the embodiment, the support lever 1
In order to limit the upward swing range of the cursor side link 1, the stopper 21 moves the cursor to a position where the extension part 15a provided extending along the cursor side link 1 comes into contact with one end of the support lever 15 at the upper limit position. It is provided on the side link 1.

As shown in FIGS. 4 and 6, the stopper 21 is configured as an eccentric shaft provided eccentrically to a support shaft rotatably supported on the mounting board 28.
By changing its rotational position, the contact position of the support lever 15 with the extension part 15a is made variable;
This constitutes support lever height adjustment stopper means for vertically variably adjusting the upper limit position of the push-up portion 17 of the support lever 15.

When the support lever 15 is at the upper limit position, the head part and the scale are in a state of floating above the drawing board, and when the support lever 15 is at the lower limit position, the head part and the scale are set in close contact with the drawing board surface. It has been done.

On the other hand, in the above embodiment of the present invention, a reinforcing head support device is provided at a position substantially parallel to the head support device. As shown in FIGS. 3 and 4, this configuration is substantially the same as the previous device, including an auxiliary lever 22, a support shaft 16, a push-up portion 23, and spring hanging shafts 24, 2.
5, consisting of a push-up spring member 26 and a stopper 21;
The push-up portion 23 is configured to abut against the lower surface of the support lever 15, thereby increasing the push-up force of the support lever 15.

That is, the auxiliary lever 22 uses the support shaft 16 as a swinging fulcrum, and when the line of action of the push-up spring member 26 is located above the swinging fulcrum, the push-up part 23 moves toward the support lever 15.
When the line of action of the push-up spring member 26 is located below the pivot point (as shown in the third and fourth figures), the auxiliary lever 22 reinforces the push-up force of the support lever 15. The push-up part 23 is configured to be held below the support lever 15 by being held at the lower limit position where it contacts the stopper 21 due to the tensile elasticity of the push-up part 23 . Further, the auxiliary lever 22 is integrally provided with an operation piece 22a, and is configured such that the line of action of the push-up spring member 26 can be selectively set above or below the support shaft 16. Further, in the case of the embodiment, the above-mentioned head support device is attached to a mounting board 28 which is attached to the cursor side link 1 with fixing screws 27, and is configured to be detachable.

Furthermore, the present invention compensates for the lack of push-up force at the time of starting by moving the support lever upward together with the head and scale when the head and scale start moving upward from the drawing surface. In order to enable smooth operation of the scale and the head part to the upright position by the support lever, in the head part support device, a guide pin is provided at the tip of the support lever, and the push-up part of the support lever is provided with a guide pin. An engaging part that removably engages with the guide pin to interlock the support lever, and a head part and a scale that slidably fit into the guide pin separated from the engaging part. The gist is that the arm guide is provided with an arm guide having a guide hole that guides the upward rotation of the arm.

That is, in the present invention, an arm guide 30 is swingably provided on the head support link 6 parallel to the side of the support lever. The arm guide 30 is connected to the head support link 6 as shown in FIGS. 5 to 7.
It is supported by a mounting plate 29 fixed to
The pivot point thereof is provided on the mounting plate 29 by a support shaft 31 that substantially coincides with the pivot axis 9a of the head support link 6. 31b is a mounting nut that is screwed into the threaded portion 31a of the support shaft 31. The arm guide 30 has an inverted dogleg shape, and has a guide hole 32 bored in its central longitudinal direction, and a guide pin 33 protruding from the spring hanging shaft 19 of the support lever 15 is inserted into the guide hole 32.
are slidably fitted. A notch-shaped engagement portion 34 is provided at the upper end of the guide hole 32, and the guide pin 33 is inserted into the notch when the head portion and scale are in contact with the drawing board surface, as shown in FIGS. 3 and 5. It is configured such that it can be positioned within the shaped engagement portion 34.
Further, 35 is a contact spring wound around the support shaft 31, and one end 35a of the contact spring is connected to the arm guide 30.
At the same time, the other end 35b is brought into contact with the inner wall of the head support link 6, and an elastic force is applied to the arm guide 30 in the clockwise direction in FIG. It is configured to engage with the notch engagement portion 34. Furthermore, as shown in FIG. 6, the rear end of the guide hole 32 is long enough to engage with the guide pin 33 at the upper limit position when the head and the scale are rotated upwards out of parallel. It is structured as follows.

In addition, an arm guide 30 swingably provided on the head support link 6, a guide pin 33 provided at the tip of the support lever 15, and a notch provided in the arm guide 30 with which the guide pin 33 is removably engaged. The engaging portion 34 constitutes arm guide means according to the present invention.

To explain the operating mode of the device of the present invention having the above-mentioned configuration, in FIGS. 3 and 5, the support lever 15 has a support shaft 16, which is the center of rotation thereof, and a spring hook shaft 18, 19 of the push-up spring member 20. Since it is located slightly above the line connecting the head support link 6, the push-up spring member 20 gives a small rotational tendency in the counterclockwise direction about the support shaft 16, and the support lever 15 moves toward the head support link 6. The pushing up force is in a state where only a small amount is applied, and at this time, the head portion and the scale are in close contact with the drawing surface. When the head section 7 is lifted by hand, the guide pin 33 is engaged with the notch-shaped engagement section 34 of the arm guide, so the support lever 15 is also rotated counterclockwise at the same time. As the supporting shaft 15 is located further down from the line connecting the spring hanging shafts 18 and 19, the pushing up force of the pushing up spring member 20 acts more strongly on the lower surface 6a of the head support link 6 via the rollers 17. That is, as the support lever 15 and the head portion 7 move upward, the push-up spring member 2
Since the tension angle formed with the support lever 15 increases, the spring elastic force that acts also increases, and the tension angle between the support lever 1 and the support lever 1 increases.
5 can support the head portion and scale in a floating state at the position where they abut against the stopper 21, as shown in FIG. At this time, the cursor side link 1 is provided with a height adjustment stopper means that comes into contact with the extended portion of the support lever to regulate the upper limit swing position of the push-up portion of the support lever.
When the spindle of the stopper 21 is rotated, the stopper 2
1 can be rotated eccentrically to change the upper limit position of the support lever 15, and the height of the head and scale can be adjusted. In addition, since the inclination angle of the drawing board is set close to horizontal, the acting force of the load on the head section and scale is large, and if the support lever 15 alone cannot sufficiently support the head in the floating position, reinforcement is required. When the auxiliary lever 22 is lifted upward from the stopper 21 and the push-up part 23 is rotated to a position where it contacts the lower surface of the support lever 15, the push-up spring member 26 simultaneously acts on the head support link 6 via the support lever 15. As a result, the head portion and scale can be supported in the floating position.

As shown in Fig. 6, when the head part and scale are rotated largely out of parallel, guide pin 3
3 is disengaged from the notch-shaped engagement portion 34 of the arm guide 30 and positioned downward along the guide hole 32. Conversely, when the guide pin 33 is returned to the parallel position shown in FIG. It will engage in the notch-shaped engagement part 34 as in the figure.

The support lever 15 and the support shaft 16 of the auxiliary lever 22 are provided on the upper part of the head support link 6, the rollers 17 are brought into contact with the cursor side link 1, and the cursor side link 1 is pushed downward by the push-up spring members 20 and 26. Even if the head support link 6 is configured to be pressed, the head support link 6 can be supported upwardly with respect to the cursor side link 1, so it goes without saying that the device of the present invention may be implemented with such a design change.

As described above, the support lever is provided with a tension spring means that applies a push-up force that increases as the head and scale move upward, and when the head and scale descend to the drawing surface, the spring acting force is weakened. A conventionally known universal parallel ruler described in Japanese Utility Model Application Publication No. 58-60495 is capable of bringing the head part and scale into close contact with the drawing board surface and strongly supporting the head part and scale at the upper limit of floating position. In the head support device shown in FIG.
Not only is there the problem of not being able to properly adjust the support height of the scale when replacing the head part or scale, but also because the upper limit stopper is configured to abut the middle part of the support lever, it is necessary to install it along the support lever. In order to prevent the upper limit stopper from coming into contact with the tension spring means,
It is necessary to provide the tension spring means at a distance from the support lever, and there is a problem that the tension spring elasticity is applied as an unbalanced load to the swing fulcrum of the support lever due to the distance of the tension spring means. In the invention, an extending portion is provided at one end of the support lever along the one link, and the one link is provided with an extending portion of the support lever to swing the pushing portion of the support lever. Since the height adjusting stopper means of the present invention is configured to variably adjust the upper limit position of the movement up and down, there is no fear that the height adjusting stopper means of the present invention will come into contact with the tension spring means provided along the support lever. Therefore, the tension spring means and the arm guide means to be described later can be installed in the immediate vicinity of the support lever, which is mechanically and structurally advantageous. While this has the effect of vertically variably adjusting the floating upper limit position of the head section and scale, a guide pin is provided at the tip of the support lever, and the other link with which the push-up part of the support lever comes into contact is provided with the support lever. An engaging part that removably engages with a guide pin to interlock the support lever, and an engaging part that slidably engages with the guide pin that is detached from the engaging part and guides the upward rotation of the head part and scale. Since the structure includes an arm guide with a guide hole, the support lever can be moved upward together with the head and the scale when starting parallel movement upward from the drawing surface, and the lack of push-up force at the time of starting can be avoided. Additionally, when the head section and the scale are further rotated upward at the upper limit of floating position, the arm guide having a guide hole in the guide pin slides and is guided to enable smooth vertical movement of the scale, and also allows the scale to move upwardly. In the moving position, the vertical position of the scale and head can be appropriately adjusted in conjunction with the height of the support lever by the height adjusting means.

[Brief explanation of the drawing]

Fig. 1 is a schematic plan view showing the main parts of an embodiment of the present invention, Fig. 2 is a bottom view of the main parts, and Figs. 3 and 4 are schematic front views showing the operating mode of the main parts. , FIG. 5 is a schematic front view of other important parts, FIG. 6 is a schematic front view showing the operation mode of the main parts, FIG. 7 is an exploded perspective view of the main parts, and FIG. 8 is an exploded perspective view of the main parts. FIG. 2 is a schematic explanatory diagram illustrating the principle of operation of the main parts of the device of the present invention. 1... Cursor side link, 2... Cursor board,
4... Vertical rail, 6... Head support link, 8...
...Upper link, 10...Lower link, 15...Support lever, 16...Spindle (swinging fulcrum), 17...
Roller (push-up part), 18, 19... Spring hanging shaft (force application point), 20... Push-up spring member, 21... Stopper,
22...Auxiliary lever, 28...Mounting board, 30...
... Arm guide, 31 ... Support shaft, 32 ... Guide hole, 33 ... Guide pin, 34 ... Engagement part, 35 ...
...Abutment spring.

Claims (1)

[Scope of utility model registration request] The head support link is connected to the cursor side link via a parallel movement mechanism so that the head part and scale are moved up and down approximately parallel to the drawing surface, and the cursor side link and the head support link are connected to each other. , one link is provided with a support lever that is swingably connected with one end as a swinging fulcrum and the other link is brought into contact with the tip end as a push-up part. In the head part support device for a universal parallel ruler, a tension spring means is provided between the movably provided link and the support lever to apply a pushing force that increases as the head part and the scale move upward. , an extending portion is provided at one end of the support lever along the one link, and the one link is in contact with the extending portion of the support lever to provide an upper limit of swing of the push-up portion of the support lever. A height adjustment stopper means for vertically variably adjusting the position is provided, and a guide pin is provided at the tip of the support lever, and the other link is removably engaged with the guide pin to interlock the support lever. A flexible parallel ruler provided with an arm guide having an engaging part that engages the scale, and a guide hole that slidably fits into a guide pin detached from the engaging part and guides the upward rotation of the head part and scale. head support device.