JPH0651440B2 - Scale balance device for universal parallel ruler - Google Patents

Description

TECHNICAL FIELD The present invention relates to a scale balance device in a universal parallel ruler.

2. Description of the Related Art A conventional device of this type is disclosed in Japanese Patent Laid-Open No. 59-17940.
The devices described in Japanese Patent Laid-Open No. 0, JP-A-60-149496 and the like are known.

In this device, when the rotating force due to the weight of the scale is balanced by a balance mechanism concentrically provided on the scale rotating shaft, an unbalanced load is applied to the scale rotating shaft, causing a scale rotation error. A first rotating member that rotates concentrically with the scale rotating shaft and a second rotating member that is separately provided on a non-rotating member of the scale operating head unit are linked by an interlocking mechanism so as to rotate in synchronization, The scale is balanced by applying a tensile force against the rotational force due to the weight of the scale to the second rotating member.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the conventional device, the second device having the same size as the first rotating member is used.
In order to provide the non-rotating member of the non-rotating member, the shape of the non-rotating member in the conventional parallel parallel ruler needs to be largely changed, and the non-rotating member has a disadvantage of being large in size. Does not completely eliminate the eccentric load for balancing the rotational force due to the self-weight of the scale, and the interlocking mechanism for rotating the first and second rotating members in synchronization reduces the rotation error of the scale rotating shaft. There is a problem that becomes a factor.

SUMMARY OF THE INVENTION Therefore, according to the present invention, a rotating member of a scale operating head portion that rotates concentrically and integrally with a scale rotating shaft is provided with an engaging member that is positionally adjustable in the radial direction of rotation. Connecting one end of a tension member having tension spring elasticity to the engagement member,
The other end of the tension member is connected to one end of the pressing mechanism member provided on the non-rotating member, and the other end of the pressing mechanism member is brought into contact with the rotating member against the tensile elasticity of the tension member. In a scale balance device for a ruler, there is provided a scale balance device for a universal parallel ruler in which an engaging member is provided on a rotating member so as to be positionally adjustable in a radial direction of rotation from a position including an axial center position of a scale rotation shaft. The locking force between the groove of the indexing plate of the indexing mechanism that locks at a predetermined rotation interval and the indexing pawl that engages with the groove is set so as to be maintained by the action of the scale balance force. To provide a scale balance device in a universal parallel ruler, and further, to lock the scale at a predetermined rotation interval, the lever of an indexing mechanism provided along the scale rotation axis is engaged. It is intended to provide a scale balance device in universal parallel ruler which is characterized by providing bent as wood and the working area does not overlap.

Action When the drawing board with the adjustable parallel ruler is tilted, the rotating force becomes zero due to its own weight when the scale faces directly above and below, and the rotating force gradually increases as it rotates from directly above to the horizontal direction. It increases, reaches a maximum in the horizontal position, and gradually decreases as it rotates downward from the horizontal position. In the scale balance device of the present invention, the rotating force that cancels the rotating force due to the weight of the scale is applied to the rotating member that rotates concentrically and integrally with the scale rotating shaft by the tension member having the tension spring elasticity. At this time, on the other hand, the spring elasticity of the tension member is applied to the same rotating member via the pressing mechanism member to cancel the tensile force of the tension member and reduce the eccentric load generated on the scale rotating shaft for balance of the scale. . Further, by adjusting the position of the engaging member in the radial direction of rotation from the center of rotation of the rotating member, for example, if the engaging member is located at the center of the scale rotation axis, the tension spring does not prevent rotation of the scale, If the engaging member is moved away from the scale rotation axis, the scale balance force is easily adjusted so that the strength of the tension spring resilience acting on the rotation member increases accordingly, and the inclination of the board from the horizontal to 90 degrees or It is possible to balance the scales corresponding to exchange use of scales having different weights.

Further, in the scale balance device, the locking force between the groove of the indexing plate of the indexing mechanism that locks the scale at a predetermined rotation interval and the indexing claw that engages with the groove can be maintained by the action of the scale balancing force. By setting the above, it is possible to reduce the width and depth of the groove and the engaging force of the claws. For example, it is easy to set the indexing angle, which has been generally 15 degrees, to 5 degrees. Moreover, there is an effect that the thickness of the indexing plate and the engaging strength of the claws can be designed to be relatively small.

Further, in the above scale balance device, in order to lock the scale at a predetermined rotation interval, the lever lever of the indexing mechanism provided along the scale rotation axis is provided so as to be bent so that the engagement member and the operating range do not overlap. As a result, there is an effect that it is possible to provide a universal parallel ruler in which the lever lever of the indexing mechanism and the engaging member of the scale balance device centered on the scale rotation axis coexist without contact.

EXAMPLE A scale balance device according to the present invention will be described in detail with reference to an example shown below. 1 is a bearing base of a scale operation head portion connected to a car sole or a pulley stand or the like that moves in parallel along the plane of the drawing board. It constitutes the non-rotating member of the present invention, and the bearing 1a thereof rotatably supports the hollow shaft rod 2. The rotating member 3 according to the present invention is integrally fixed to the upper part of the shaft rod 2 with a screw 3a, and the scale support base 4 is integrally fixed to the lower part with a screw 4a. Since the shaft rod 2 is a member that is integral with the rotating member 3 as a rotating function, it is not necessary to distinguish between the shaft rod 2 and the rotating member 3. When the shaft rod 2 is referred to as a rotating member, it is referred to as a member including the shaft rod 2. It should be recognized. A handle 5 for scale operation is integrally fixed to the upper part of the rotating member 3,
A scale mounting plate 6 is fixed to the tip of the scale support base 4, and the lower scale mounting plate 6 is fixed by the handle 5.
It is configured so that the scale attached to can be rotated. A graduation plate 7 that can be fixed to the bearing base 1 at any time by a fixing lever 8 is rotatably attached to the outer peripheral portion of the lower portion of the bearing portion 1a. On the scale support base 4 side so as to face the vernier scale of the vernier plate 9 fixed by screws 9c via spacers 9a and 9b. Numeral 7a is a degree-baseline index board which is integrally provided on the support base 1 so as to face the inner circumference of the degree scale of the protractor board 7, and which is provided so that the rotation angle of the protractor board 7 with respect to the support base 1 can be recognized. is there. The scale plate 7 is also provided with a scale fixing plate 10 and an indexing plate 11 integrally fixed to each other.
The scale fixing lever 10a can be fixed to the scale supporting base 4 at any time, and the indexing plate 11 can be fixed to the scale supporting base 4 by engaging the indexing claws 12 with the grooves 11a at predetermined angles. The groove width and the groove interval of the groove 11a of the indexing plate 11 can be configured to be small, for example, to an interval of about the plate thickness of the indexing plate 11 which is a processing limit of punching by the balance force of a scale balance device described later. The indexing angle interval of 15 degrees can be arbitrarily narrowed to 5 degrees or less, and the engaging force between the groove 11a and the indexing claw 12 is disengaged when the load due to the weight of the scale becomes maximum. The engagement force can be set to a small degree. The indexing claw 12 and the interlocking piece 13 that interlocks along the lower surface of the scale support base 4, and the lever rod 1 that penetrates the hollow portion of the shaft rod 2 and the rotating member 3 are provided.
4 and a lever 15 provided on the side portion of the handle 5 are interlocked with each other, and are provided on the indexing plate 11 so that they can be engaged and disengaged. In this case, the lever rod 14 engages with the interlocking piece 13 at the lower end 14a and interlocks with the lever 15 at the upper end 14b. Reference numeral 13a is a spring member provided to give the interlocking piece 13 a tensile elastic force in a direction in which the indexing claw 12 is always engaged with the groove 11a. Here, the lever lever 14 is bent at a bent portion 14c at the upper portion of the shaft rod 2 so as to swing about a narrow portion 2a provided on the hollow inner upper portion of the shaft rod 2 and engages with the lever 15. Reference numerals 16 and 17 denote cover bodies that rotate integrally with the scale mounting plate 6, and a loupe 18 is provided at a portion facing the vernier plate 9. 19 is a scale mounting screw.

Here, in the rotating member 3 according to the present invention, the screw shaft 20 having the shaft center along the radial direction from the rotation center is provided with the operation grip portion 2.
1, the engaging member 22 is engaged with the screw shaft 20 so as to be movable in the radial direction from the center of rotation. In the case of the embodiment, the screw shaft 20 is provided inside the guide frame 3b in the rotating member 3, and the engaging member 22 is screwed into the screw shaft 20 in the guide frame to rotate the screw shaft 20. Accordingly, the rotary member 3 can be freely reciprocated in the radial direction from the rotation center position. A lower end of the engaging member 22 is connected to a tip end of a linking member 27 that is inserted through the side opening 3c of the rotating member 3, and a spring hook 28 is provided at a rear end of the linking member 27. Further, the other end portion 24 of the pressing mechanism member 23 according to the present invention is projectingly provided on the bearing base 1 along a line intersecting with the screw shaft 20, and the other end portion 2
A tension member 25 having a tension spring elasticity is stretched between 4 and the spring hook portion 28 of the link member 27.

In the case of the embodiment, the tension member 25 is made of a coil spring, is stretched over the engagement member 22 via the linking member 27, and is stretched corresponding to the radius of rotation of the engagement member 22 that rotates as the rotation member 3 rotates. The pressing mechanism member 23 is pulled by force. Further, the pressing mechanism member 23 is configured by a bent rod-shaped integral member whose movement is restricted by the guide pins 23a and 23b in parallel with the longitudinal direction of the tension member 25, and one end thereof is bent downward to be rotatable. The contact member 26, which is made of a simple bearing or the like, is configured to elastically contact the contact ring 3d on the lower side of the rotating member 3 in the radial direction of one rotation.

The positional relationship between the engaging member 22 of the rotating member 3 that rotates integrally with the scale (scale mounting plate 6) and the tension member 25 is such that the center of gravity of the scale S is directly above as shown in FIGS. When the rotating force due to the weight of the scale is not applied to the rotating member 3, the engaging member 22 is on the one radius of the rotating member 3 closest to the pulling member 25 as shown in FIG. And the contact member 26 is the rotating member 3
Located along a straight line passing through the rotation center O of the tension member 2
The elastic force of the tension spring 5 does not give any rotating force to the rotating member 3 and balances with the rotating force of zero due to the own weight of the scale S. Next, when the center of gravity of the scale is rotated 90 ° with the engaging member 22 in the horizontal direction shown in FIG. 4 from directly above, the pulling member 25 causes the pulling member 25 to center on the connecting portion 24 with the pressing mechanism member 23. The pulling angle is gradually increased from one radius on the drawing to apply a rotating force against the rotating force due to the weight of the scale to the rotating member 3.
And the maximum rotational force is applied to the rotary member 3 at the maximum tension angle in the state of FIG. 4 in which the center of gravity of the scale is horizontal,
The rotation force due to the weight of the scale is offset, and the contact member 26 applies the tension spring elasticity of the tension member 25 from one radial direction of the rotation member 3 to the side surface thereof, so that the tension member 25 applied to the rotation member 3 is biased. Reduce the load. At the subsequent rotational position of the scale from the horizontal direction to the direct downward direction, the tensile angle of the tensile member 25 gradually decreases, and the engaging member 22 is farthest when the center of gravity of the scale in FIG. 5 is positioned directly below. At the position, the tension member 25 and the abutment member 26 are positioned linearly along one diameter of the rotating member 3 as in the state shown in FIG. 3, and the tension spring resilience of the tension member 25 is offset, No rotational force is applied to the rotating member 3, and the rotational force due to the weight of the scale 6 becomes zero.

Further, the tensile resilience of the tension member 25 acts more as the engaging member 22 moves away from the center of the rotating member 3 in the radial direction, so that the tension elastic force corresponds to the inclination from the horizontal to the upright of the drawing plate.
By adjusting the position of the engaging member 22 away from the center position of the rotating member 3 in the radial direction, the scale can be always placed in a balanced state.

As described above, according to the device of the present invention, the second device
Rotation that cancels the rotational force due to the weight of the scale with a tension member that has tension spring resilience to a rotation member that rotates concentrically and integrally with the scale rotation axis without complicating the structure by providing the rotation member on the non-rotation member On the other hand, by applying the spring elasticity of the tension member to the same rotating member via the pressing mechanism member on the other hand, the tension force that acts on the rotating member as an unbalanced load in order to balance the scale is offset. However, it is possible to reduce the rotation error of the scale rotation shaft caused by the balance of the scale, and to adjust the position of the engagement member in the rotation radius direction from the position including the axis center position of the scale rotation shaft on the rotation member. Since it has a configuration that is provided, the drawing plate is almost horizontal, as when using the universal parallel ruler on a horizontal desk, so the rotating force due to the weight of the scale does not occur. In such a case, by adjusting the position of the engaging member with respect to the rotating member so as to be located at the axial center position of the scale rotating shaft, the tension spring elasticity of the tension member is irrespective of the rotating position of the scale rotating shaft. The scale balance device of the present invention can be smoothly smoothed even in a horizontal state without weakening or removing the tension spring elasticity of the tension member, since the rotation of the scale can be canceled and the scale rotation can be prevented. The effect is that it can be adjusted for use.

Further, in the scale balance device, the locking force between the groove of the indexing plate of the indexing mechanism that locks the scale at a predetermined rotation interval and the indexing claw that engages with the groove can be maintained by the action of the scale balancing force. By setting the above, it is possible to reduce the width and depth of the groove and the engaging force of the claws. For example, it is easy to set the indexing angle, which has been generally 15 degrees, to 5 degrees. In addition, the thickness of the indexing plate and the engaging strength of the claws can be designed to be relatively small.

Further, in the above scale balance device, in order to lock the scale at a predetermined rotation interval, the lever lever of the indexing mechanism provided along the scale rotation axis is provided so as to be bent so that the engagement member and the operating range do not overlap. As a result, there is an effect that it is possible to provide a universal parallel ruler in which the lever lever of the indexing mechanism and the engaging member of the scale balance device centered on the scale rotation shaft coexist without contact.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing a main part of an embodiment of the device of the present invention, and FIG. 2 is a vertical sectional front view showing the main part in a vertical section.
FIG. 5 to FIG. 5 are schematic explanatory views showing an operating mode of the main part. 1 ... Bearing base (non-rotating member) 2 ... Shaft rod 3 ... Rotating member 4 ... Scale support base 5 ... Scale operating handle 6 ... Scale mounting plate 20 ... Screw shaft 22 ... Engaging member 23 ... Pressing mechanism member 25 ... Pulling member 26 ... Abutting member 27 ... Linking member

Claims (13)

[Claims] 1. A rotary member of a scale operating head portion, which rotates concentrically and integrally with a scale rotary shaft, is provided with an engaging member whose position can be adjusted in a radial direction of rotation, and a tension spring elastic force is applied to the engaging member. The one end of the pulling member having is connected, the other end of the pulling member is connected to one end of the pressing mechanism member provided on the non-rotating member, and the other end of the pressing mechanism member resists the tensile elasticity of the pulling member. In a scale balance device in a free parallel ruler abutting against a rotary member, a free parallel ruler in which an engaging member is provided on the rotary member so as to be positionally adjustable in a radial direction of rotation from a position including an axial center position of a scale rotation shaft. Scale balance device 2. The scale balance device in a universal parallel ruler according to claim 1, wherein the engaging member is configured to be positionally adjustable with rotation of a screw shaft provided on the rotating member. 3. The device according to claim 1 or 2, wherein the rotary member has a guide frame, and the position of the rotary member is adjustable by rotation of the screw shaft. Scale balance device for universal parallel ruler with engaging members 4. The device according to claim 1, wherein the pressing mechanism member receives a tension spring elastic force of a tension member applied to one end thereof, and the other end of the rotation member is a rotating member. Scale balance device in a universal parallel ruler consisting of an integral member that abuts the side surface 5. A rotary member of the scale operating head part, which rotates concentrically and integrally with the scale rotary shaft, is provided with an engaging member whose position is adjustable in the radial direction of rotation, and a tension spring elastic force is applied to the engaging member. The one end of the pulling member having is connected, the other end of the pulling member is connected to one end of the pressing mechanism member provided on the non-rotating member, and the other end of the pressing mechanism member resists the tensile elasticity of the pulling member. In a scale balance device in a free parallel ruler that is brought into contact with a rotating member, the locking force between the groove of the indexing plate of the indexing mechanism that locks the scale at a predetermined rotation interval and the indexing claw that engages with the groove is Scale balance device in a universal parallel ruler characterized by being set so that it can be maintained by the action of a balance force 6. The scale balance device in a universal parallel ruler according to claim 5, wherein the engaging member is configured to be positionally adjustable with rotation of a screw shaft provided on the rotating member. 7. The apparatus according to claim 5 or 6, wherein the rotating member has a guide frame, and the position of the rotating member is guided by the rotation of the screw shaft. Scale balance device for universal parallel ruler with engaging members 8. The device according to claim 5, wherein the pressing mechanism member receives a tension spring elasticity of a tension member applied to one end thereof, and the other end of the rotation member is a rotating member. Scale balance device in a universal parallel ruler consisting of an integral member that abuts the side surface 9. A rotating member of a scale operating head part, which rotates concentrically and integrally with a scale rotating shaft, is provided with an engaging member whose position can be adjusted in a radial direction of rotation, and a tension spring elastic force is applied to the engaging member. The one end of the pulling member having is connected, the other end of the pulling member is connected to one end of the pressing mechanism member provided on the non-rotating member, and the other end of the pressing mechanism member resists the tensile elasticity of the pulling member. In a scale balance device in a free parallel ruler that is brought into contact with a rotating member, in order to lock the scale at a predetermined rotation interval, a lever lever of an indexing mechanism provided along the scale rotation axis is provided between the engaging member and the operating area. Scale balance device for a flexible parallel ruler characterized by being bent so that they do not overlap 10. The device according to claim 9, wherein a lever of an indexing mechanism provided along the scale rotation shaft is attached to the hollow scale rotation shaft to lock the scale at a predetermined rotation interval. A scale balance device in a universal parallel ruler, which is supported by a narrow portion as a fulcrum, and is bent and provided above the fulcrum so that the engagement member does not overlap with the operating region. 11. The scale balance device in a universal parallel ruler according to claim 10, wherein the engaging member is configured to be positionally adjustable with rotation of a screw shaft provided on the rotating member. 12. The apparatus according to claim 10 or 11, wherein the rotating member has a guide frame, and the position of the rotating member is adjustable by rotation of the screw shaft. Scale balance device for universal parallel ruler with engaging members 13. The device according to claim 10, wherein the pressing mechanism member receives a tension spring elastic force of a tension member applied to one end thereof, and the other end of the rotation member is a rotating member. Scale balance device in a universal parallel ruler consisting of an integral member that abuts the side surface