JPH0443000B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a universal parallel ruler in which when the straightedge is free from a non-rotating member on an inclined drawing board, the straightedge is placed on the drawing surface. This invention relates to a balancing device for a ruler to maintain a stable stationary state without suddenly rotating in the falling direction.

[Prior art] Various types of balance devices have been devised, but they can be roughly divided into balance weight systems, balance weight systems,
There are eccentric cam type and spring type. In the balance weight system, the weight of a balance weight is applied in a direction opposite to the direction of rotation of the straight edge on a member that is interlocked with the rotation of the straight edge in the falling direction, thereby balancing the ruler. In the eccentric cam method, an elastic body is brought into elastic contact with an eccentric cam that moves in conjunction with the rotation of a straight edge, and the elastic force of this elastic body applies rotational torque to the eccentric cam in the opposite direction to the direction of rotation due to the straight edge's own weight. generate,
This keeps the straightedge balanced. In the spring method, a spring acts on the eccentric portion of a disc that rotates in conjunction with the straightedge, and the spring force generates a rotating torque for balance on the disc, thereby balancing the straightedge.

[Problem that the invention seeks to solve]

The above-mentioned balance weight method has the disadvantage that the weight becomes large, the device becomes large-sized, and the rotation of the straightedge becomes difficult due to the inertial force of the balance weight. The eccentric cam system has a drawback in that a frictional force is generated by the elastic contact force between the elastic body and the eccentric cam, and this frictional force makes the rotation of the straight edge heavier.

Although the above spring method does not have the defects of the above two methods, it does have the following problems.
This problem will be explained with reference to the explanatory diagram shown in FIG.

A spring 6 attached to the non-rotating body side of the head is attached to the rotating body 4 to which the straight edge 2 is connected, and the tensile force of the spring 6 is applied to the eccentric portion of the rotating body 4, so that the straight edge 2 is at approximately +90 degrees position. At some point, the tensile force of the spring 6 is set to zero, and the rotational torque of the rotating body 4 about the multiple shaft 8 is set to zero. In the above configuration,
Assume that when the rotating body 4 is rotated so that the straightedge 2 is at zero degrees as shown in FIG. 4b, a tensile load of, for example, 5 kg of the spring 6 acts on the rotating body 4. At this time, the rotational torque of the rotating body 4 due to the spring 6 becomes maximum.
Furthermore, the ruler 52 moves the rotating body 4 in the direction of rotation of the hour hand by -90 degrees.
When the rotating body 60 is rotated until it reaches the desired angle (see FIG. 5C), the spring force becomes 10 kg and the rotational torque of the rotating body 60 becomes zero. In this case, a load of 10 kg is applied between the rotating body 4 and the multiple shaft 8 due to the spring force. This increases the pressure load of the rotating body 4 on the multiple shaft 8, which adversely affects the durability of the head and the angular accuracy of the ruler 2. However, Fig. 4 d to f
As shown in FIG.
In a configuration in which the teeth provided on the outer periphery of each are engaged and the spring 6 is attached to the eccentric part of the second rotating body 10, when the ruler 2 is at +90 degrees, the spring force is zero and the torque of the rotating body 62 is zero. When the ruler 2 is at zero degrees, the spring force is 5 kg, and the rotating body 1
The torque at 0 is maximum, as shown in Figure 4 f, ruler 2
When the rotating body 10 is rotated until the angle becomes -90 degrees, the spring force becomes 10 kg, but the rotational torque of the rotating body 10 is zero. In this case, since only the torque of the rotating body acts on the rotating body 4, the pressure load acting between the rotating body 4 and the multiple shaft 8 is zero. As is clear from the above description, the rotating body to which the ruler is connected is engaged with the second rotating body provided on the non-rotating body side of the head,
By applying a spring force to the second rotating body, the pressure load between the rotating body and the multiple shafts can be reduced.

The main object of the present invention is to rotatably support a second rotating body on the non-rotating member side of the head, and to apply a spring to the second rotating body to balance a ruler provided on the non-rotating member. At the same time, the second rotating body is engaged with the rotating body of the head, so that the rotating body of the head can smoothly rotate about multiple axes.

Next, other objects of the present invention will be explained. When the drawing board is tilted in the vertical direction, the rotational torque of the rotating body 4 in the direction of the hour hand about the multiple shaft 8 is applied to the rotating body 4 due to the total weight of the rotating body 4 and the ruler 2 etc. connected thereto. arise. This rotational torque is maximum when the ruler 2 is at zero degrees. Therefore, the rotational torque of the rotating body 10 must also be maximized at this time. However, if the angle of the ruler 2 is, for example, +90 degrees when the rotational torque of the rotating body 10 is maximum, the rotating body 60 is rotated with the rotating body 62 stopped.
must be rotated until the ruler 52 is at zero degrees. However, if the rotating bodies 10 and 4 are engaged, the angle of the ruler 2 cannot be adjusted to zero degrees. If the ruler 2 is rotated to zero degrees, the rotating body 10 will rotate in conjunction with the rotating body 4. When the rotating body 10 rotates, its rotational torque also changes.

The present invention aims to eliminate the above-mentioned defects.

[Means to solve problems]

In order to achieve the above object, the present invention includes a head that can be moved to any position on a drawing board while maintaining a predetermined orientation, and a tubular double shaft that is vertically installed on the non-rotating member side of the head. A flexible parallel ruler comprising a main shaft rotatably inserted into the multi-shaft, a ruler mounting plate attached to the main shaft, and a straight ruler attached to the ruler mounting plate, wherein a circumference is formed on the main shaft side. A first rotating body having teeth formed on its circumferential portion is attached, and an intermediate gear and a second rotating body having teeth formed on its circumferential portion are rotatably supported on the non-rotating member side of the head, and the intermediate gear meshes with each of the first and second rotating bodies,
A spring means is linked to the second rotating body to generate rotational torque in a direction that substantially cancels out the rotational torque of the first rotating body due to the weight of the straightedge, etc., and the intermediate gear is rotated by the intermediate gear. The present invention is characterized in that it can be displaced in a direction in which at least one of the first and second rotary bodies is brought out of mesh with the rotary body.

[Effect]

In the above configuration, when the head is stationary on the inclined drawing board, the weight of the ruler mounting plate, straightedge, etc. generates a rotational torque around the inner peripheral surface of the tubular double shaft on the main shaft. A straightedge, etc. tries to rapidly rotate in the direction of fall along the drawing board. on the other hand,
The spring force of the spring means acts on the second rotating body, and a balancing rotational torque is generated on the second rotating body. The rotational torque of this second rotating body is transmitted to the main shaft via the intermediate gear and the second rotating body, and this rotational torque cancels out the rotational torque of the main shaft due to the weight of the straightedge, etc., and the main shaft is balanced. . When the intermediate gear is displaced and the meshing state between the intermediate gear and the first and second rotating bodies is released, the second rotating body is connected to the first rotating body while the first rotating body is stationary. The rotation can be adjusted. Further, on the contrary, the first rotating body, that is, the straightedge, can be rotated and adjusted while the second rotating body is kept stationary. As a result, the phase of the change characteristic of the rotational torque of the second rotating body is changed to the first
It is possible to match the phase of the change characteristic of the rotational torque due to the weight of the straightedge of the rotating body.

〔Example〕

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

In FIG. 3, reference numeral 22 denotes a drawing board, which is supported by a support frame of a drafting table which can be tilted freely so as to be fixed at a desired angle of inclination. 24 is a horizontal rail arranged on the upper side of the drawing board 22, and a horizontal cursor 26 is movably attached to this rail. The horizontal cursor 26 is connected to the upper end of a vertical rail 28 . The lower end of the vertical rail 28 is movably placed on the drawing board 22 via a tail roller. 32 is a vertical cursor movably attached to the vertical rail 28, and a known double hinge mechanism 3 is attached to this vertical cursor.
A support substrate 38 of the head 36 is connected to the head 36 via the head 4. A tubular multi-shaft 4 is attached to the tubular portion of the support substrate 38.
0 is fixed by a nut 41. In FIG. 1, 42 is a tubular main shaft, the outer peripheral surface of which is rotatably fitted into the inner peripheral surface of the multi-shaft 40, and a mounting plate 44 is attached to the upper part of the main shaft 42 with a nut.
is fixed. A grip handle 46 is fixed to the mounting plate 44 with screws 47. 48
is a scale mounting plate fixed to the lower end flange of the main shaft 42, and straightedges 52, 54 are fixed to this as shown in FIG. The scale mounting plate 48 and a protractor plate 56 fixed to the support substrate 38
Between the scale mounting plate 48 and the protractor plate 56,
A known index mechanism and a scale mounting plate for releasably fixing the scale at every 15 degrees are attached to the protractor 5.
6 is provided with a known angle fixing mechanism for releasably fixing at a desired angle. Reference numeral 60 denotes a rotating body in which gears are meshed with the outer periphery of a cylindrical body, and is fixed to the mounting plate 44 with screws. 62
is an intermediate gear, and an outer ring of a ball bearing 63 is fitted and positioned on the inner diameter of the intermediate gear, and the inner ring of the ball bearing 63 is slidably fitted to the outer circumferential surface of a tubular protrusion 38a protruding from the support substrate 38. are doing. A coil spring 65 is compressed and fitted onto the outer circumferential surface of the protrusion 38a, and the elastic force of the coil spring 65 causes the upper end surface of the inner ring of the ball bearing 63 to snap into place with the head of the screw screwed into the protrusion 38a. It is in elastic contact with the lower surface of the portion 67. The intermediate gear 62 meshes with the gear of the first rotating body 60. located above the intermediate gear 62,
Holes 71 and 73 for pressing the intermediate gear from the outside are provided in the support substrate 38. 66
is a shaft fixed to the support substrate 38, and the center of the upper horizontal portion of the cylindrical rotating body 68 is rotatably supported by the shaft. A gear is formed on the outer periphery of the rotating body 68, and the gear meshes with the intermediate gear 62. A guide groove is formed in the diametrical direction of the rotating body 68, and a bridge member 72 is slidably disposed in the guide groove along the longitudinal direction of the guide groove. Reference numeral 74 denotes a threaded shaft installed in the peripheral wall of the lower part of the rotating body 68 in the diametrical direction of the rotating body 68, and the molding 76 is screwed into this. The circumferential groove of the molding 76 is rotatably fitted into the bridge member 72, and the bridge member 72 is configured to move in conjunction with the movement of the molding 76 along the screw shaft 74. 78
is a coil spring whose one end is hooked to a pin protruding from the support substrate 38, and the other end of which is connected to one end of a flexible and bendable wire rope 80, which wire rope 80 is A guide pulley 8 rotatably supported by the support substrate 38
2 and 84, and the other end of the wire rope 80 is rotatably connected to the bridge member 72 via a metal terminal 86. When the center of the metal fitting terminal 86 is located at the rope regulating end E of the guide pulley 84, the rope 80 is just pushed by the spring 78.
The initial zero position of the spring 78 is set such that the tension of the spring 78 is zero, and
are the scale mounting plate 48 and the straightedge 52,
A spring having a spring constant corresponding to the weight, such as 54, is used. Next, the operation of this embodiment will be explained.

When a finger or a stick is inserted through the holes 71 and 73 of the support substrate 38 and the upper surface of the intermediate gear 62 is pressed, the intermediate gear 62 descends against the elasticity of the coil spring 65, thereby causing the intermediate gear 62 and the The meshing state with the first and second rotating bodies 60 and 68 is released. In this state, the first rotating body 60 and the second
The rotating bodies 68 can be rotated independently. As shown in FIG. 3, when the horizontal straightedge 52 is substantially horizontal with respect to the horizontal rail 24, the rotational torque of the main shaft 42 due to the weight of the straightedge 52, etc. becomes maximum. Therefore, in this state, the rotating body 68 is rotated to set the rotational torque of the rotating body 68 by the spring 78 to the maximum. Next, when the pressure on the intermediate gear 62 is released, the intermediate gear 62 rises due to the elastic force of the coil spring 65, and the intermediate gear 62
The rotating bodies 68 and 60 mesh with each other. In this state, first, the drawing board 22 is set at a desired inclination angle in the upright direction with respect to the floor surface. Grasp the handle 46 of the head 36 with your hand, and move the handle 46 to the drawing board 2.
By applying pressure in any direction parallel to the two surfaces, the head 36 can be translated to a desired location on the drawing board 2. With the head 36 held stationary at any position on the drawing board 22 by a known head balance mechanism, the scale mounting plate 48 can be freely rotated around the multi-axis tube 40 by operating a known indexing mechanism. state. That is, the fixation of the scale mounting plate 48 to the non-rotating member is released. In this state, the rotating body 6 is moved by the weight of the scale mounting plate 48, straightedges 52, 54, etc.
In other words, a rotational torque T' about the main shaft 42 is generated in the first rotating body 60 which is interlocked with the scale mounting plate 42. This rotational torque T' and the spring 7
8, the magnitude of the rotational torque T acting on the rotating body 68 is the same, and the rotational torque T is applied to the first rotating body 60 via the intermediate gear 62, canceling out the rotational torque T'. Acts on the direction. Therefore, even if the straightedges 52 and 54 are in a free rotation state,
It stands still on the drawing board 22 and does not rotate suddenly due to its own weight. When the straight edge 52 is rotated by approximately +90 degrees until it is upwardly parallel to the vertical rail 8, the rotational torque due to the weight of the straight edges 52, 54, etc. of the rotating body 60 becomes zero. At this time, terminal 86
is closest to the guide pulley 84, and the spring 7
The so-called radius of rotation of the second rotating body 68 as a rotational torque generating element due to the rotational force 8 becomes zero. When the straightedge 52 is rotated by approximately -90 degrees, the rotational torque due to the weight of the straightedges 52 and 54 on the rotating body 60 becomes zero. At this time, the terminal 86 is farthest away from the guide pulley 84, the rope 80 is located on the central extension line of the rotation center axis 66 of the second rotating body 68, and the tensile force of the spring 78 is maximum. However, this tensile force is supported by the shaft body 66 on the non-rotating member side and does not act on the rotating body 60.

Next, the operation of adjusting the rotation radius will be explained.

When the molding 76 is rotated, the bridge member 72 moves along the screw shaft 74, and the rope terminal 86 moves in the radial direction on the rotating body 68 in conjunction with the bridge member 72. As the rope terminal 86 moves, the distance between the rope connection point and the center of rotation of the rotating body 68 changes. When the inclination angle of the drawing plate 22 is changed, the value of the load applied to the scale mounting plate 48 due to the weight of the straight edge or the like changes in accordance with this change.
Therefore, when the inclination angle of the drawing board 22 is changed, by adjusting the rotation of the molding 76, the rotational torque generated in the rotating body 68 due to the load can be reduced.
The magnitude of the rotational torque T generated on the rotating body 68 by the tensile load of the spring 78 can be made to match T'.

In addition, the coil spring 78 and the rope 8
0 constitutes a spring means that generates a rotational torque in the second rotating body 68 that changes approximately in a sine curve as the second rotating body 68 rotates.

〔effect〕

As described above, in the present invention, the unbalanced load of the balance spring is supported by the support part of the second rotating body, so the spring force is not applied as an unbalanced load to the main shaft, and the rotation of the main shaft is light and smooth. can be done. Furthermore, by releasing the meshing between the intermediate gear and the first or second rotary body, the rotation of the first and second rotary bodies can be adjusted independently.
The angle of the second rotating body can be adjusted with the straightedge stationary. Furthermore, since the intermediate gear is provided on the support substrate of the head, there is an effect that the grip handle of the head does not get in the way when the intermediate gear is disengaged from the first or second rotating body.

[Brief explanation of the drawing]

FIG. 1 is a sectional view, FIG. 2 is a plan view, FIG. 3 is a plan view, and FIG. 4 is an explanatory view. 2...Straightedge, 4...Rotating body, 6...Spring, 8
...Multi-axis, 10...Rotating body, 12...Axis, 22...
...Drawing board, 24...Horizontal rail, 26...Horizontal cursor, 28...Vertical rail, 32...Vertical cursor, 3
6...Head, 38...Support board, 40...Multi-shaft, 41...Nut, 42...Main shaft, 44...Mounting plate, 46...Handle, 48...Scale mounting plate, 52, 54... Straight edge, 56... Protractor board, 6
0... Rotating body, 62... Intermediate gear, 66... Shaft body, 68... Rotating body, 72... Bridge member, 74...
Screw shaft, 76...Mall, 78...Coil spring.

Claims (1)

[Claims] 1. A head that can be moved to any position on the drawing board while maintaining a predetermined orientation, a main shaft that is rotatably inserted into the non-rotating member side of the head, and a ruler attached to the main shaft. In a universal parallel ruler equipped with a plate and a straightedge attached to the ruler mounting plate, a first rotating body having teeth formed on the circumference is attached to the main shaft side, and a first rotating body having teeth formed on the circumference is attached to the main shaft side, and rotatably supports an intermediate gear and a second rotating body having teeth formed on its circumferential portion, and the intermediate gear is mounted on each of the first and second rotating bodies, and the intermediate gear is supported on each of the first and second rotating bodies. The other end of the spring means is connected to the eccentric portion of the second rotating body so as to rotate synchronously, and one end of the spring means is connected to the non-rotating portion side of the head 22. The intermediate gear is connected to the first gear so as to generate a rotational torque in a direction that almost cancels out the rotational torque due to the weight of the straightedge, etc. of the rotating body, and the intermediate gear is connected to the first gear.
A balancing device for a ruler, characterized in that the ruler can be displaced in a direction in which at least one of the second rotating body and the second rotating body are disengaged from each other.