US3869897A

US3869897A - Apparatus for correcting deformation of a slender metallic products

Info

Publication number: US3869897A
Application number: US425850A
Authority: US
Inventors: Hiroshi Iida
Original assignee: Mannoh Industrial Co Ltd
Current assignee: Mannoh Industrial Co Ltd
Priority date: 1973-12-18
Filing date: 1973-12-18
Publication date: 1975-03-11
Anticipated expiration: 1992-03-11

Abstract

The present invention relates to an apparatus for correcting deformation of a slender metallic product using the so-called ''''Bauschinger Effect'''' which comprises a fixed support to fix a part of a slender metallic product thereon, a fixing means to forcibly fix a deformed part of said product fixed on said support at a position in which there is substantially no deformation, a swing motion creating means to give a swing motion to said fixing means, said swing motion being of the type of that initially the center of amplitude is on the center of the swing motion and in one direction grows gradually larger, and then is reversed in the opposite direction, and a swinging board which is engaged with said swing motion creating means and swings upwards and downwards, and from left to right.

Description

United States Patent 1 1 Iida [ Mar. 11, 1975 APPARATUS FOR CORRECTING DEFORMATION OF A SLENDER METALLIC PRODUCTS [52] US. Cl 72/125, 72/112 [51] Int. Cl ..B21d 3/00 [58] Field of Search ..72/l12,l20, 121,125,

[56] References Cited UNITED STATES PATENTS 3,349 8l3 10/1967 Pastuszak 140/147 Primary ExaminerLowell A. Larson Attorney, Agent, or Firm-Henry R. Lerner [57] ABSTRACT The present invention relates to an apparatus for correcting deformation of a slender metallic product using the so-called Bauschinger Effect which comprises a fixed support to fix a part of a slender metallic product thereon, a fixing means to forcibly fix a deformed part of said product fixed on said support at a position in which there is substantially no deformation, a swing motion creating means to give a swing motion to said fixing means, said swing motion being of the type of that initially the center of amplitude is on the center of the swing motion and in one direction grows gradually larger, and then is reversed in the opposite direction, and a swinging board which is engaged with said swing motion creating means and swings upwards and downwards, and from left to right.

8 Claims, 10 Drawing Figures minimum 1 m5 869,897

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F'ATENTED 1 5 7 869 897 sum 2 o 4 PATENTEUHAR 1 '1 I975 saw u 0g 9 emnnflfl/WM HHHHHHAAAC WUUUUUUW A ELO Number of swing motion FIG.|O

APPARATUS FOR CORRECTING DEFORMATION OF A SLENDER METALLIC PRODUCTS The present invention relates to an apparatus for correcting deformation of a slender metallic product.

A deformation of a slender metallic product, excepting such as a round rod having a simple form ofa circular section and being elongated longitudinally, had hitherto corrected only by hand finishing, and therefore, such correcting operation is very inefficient.

An object of the present invention is to mechanically correct deformation of a slender metallic product which has a complicated form in section and a complicated longitudinal form.

According to the present invention, in correcting treatment of a complicated form in section and a complicated longitudinal form, firstly an angular deformation of the product along its longitudinal axis can mechanically be corrected, secondarily deformation of a linear part of the product can mechanically be corrected and straightened, and thirdly torsional deformation in direction of its axis can mechanically be removed.

In this invention, the so-called Bauschinger Effect is utilized, and the most important feature of its effect is that correcting deformation can accurately be effected by forcibly putting a deformed part of a slender metallic product fixed by its other part in accord with a center of swing motion, by giving a swing motion to said deformed partin one direction, the amplitude of which motion being gradually made larger, and by imparting a reverse swing motion in other direction to said deformed part.

The word deformation used in this specification is not intended to represent a strain for the stress in the material sciences jargon, but to represent a difference between the size of a finished product and its intended size and shape.

According to this invention, an apparatus is provided for correcting deformation of a slender metallic product in which an apparatus for correcting deformation of a slender metallic product comprising a fixed support to fix a part of a slender metallic product, thereon, a fixing means to forcibly fix a deformed part of the slender metallic product fixed on said fixed support to a position at which there is substantially no deformation, a swing motion creating means to give a swing motion to said fixing means, said swing motion being of the type of that initially the center of amplitude is on the center of the swing motion and in one direction grows gradually larger, and after then is reversed in the opposite direction, and a swinging board which is engaged with said swing motion creating means and swings upwards and downwards, and from left to right.

These and other features of the present invention will be apparent from the following description with reference to an embodiment represented by the way of an example in the accompanying drawings, in which;

FIG. 1 is a front elevation of an apparatus according to the present invention partly in section,

FIG. 2 is a sectional elevation of a swing motion cre ating means which is a main part of the apparatus according to the present invention,

FIG. 3 is a side elevation viewed along line III-III of FIG. 1,

FIG. 4 is a plan view of a slender metallic product, as an example, to be corrected by the apparatus according to the present invention,

FIG. 5 is a elevation view of the same product,

FIG. 6 is a side view of the part of FIG. 2 along the line VIVI of FIG. 2,

FIG. 7 is a similar view to FIG. 6 after rotating the part therein,

FIG. 8 is a diagram for explaining the theory used in the present invention,

FIG. 9 is a diagram representing a result of an experiment according to the present invention, and

FIG. 10 is a side view of another embodiment of the present invention for correcting deformation of a straight portion.

Referring FIGS. 1, 2 and 3, numeral 1 represents general means for creating a swing motion which forms a main part of the apparatus for correcting deformation of a slender metallic product according to the present invention. A swinging board 2 is provided on the left side of said means 1. On the surface of said swinging board 2, there are radially fixed four

hydraulic cylin ders

3a, 3b, 3c and 3d, and piston rods 9a, 9b, 9c. and 9d for supporting an adapter 4. Fixed supports 50 and 5b are arranged in desired relation with an auxiliary shaft 6 of said means for creating a swing motion. Above said fixed supports 5a and 5b,

hydraulic cylinders

7a and 7b are provided, and their piston rods are adapted to press a slender metallic product 8 to be corrected for its deformation against said fixed supports 5a and 5b as shown in FIG. 1.

Said slender metallic product 8 is shown as an example in FIGS. 4 and 5. As shown in said figures, said product is in a complicated form, and it has

standard points

8a, 8b, outer ends 80, 8d, and a center point Se in design size. In said figures, contours represented by a solid line is that for the desired design, and contours represented by a chain line is that for the deformed product.

In operation, said slender metallic product is fixed on the apparatus as shown in FIG. 1, that is,

standard points

8a and 8b are fixed between the fixed supports 5a and 5b and piston rods of the corresponding

hydraulic cylinders

7a and 7b, respectively, and the one outer end 8d to be corrected is inserted into a center hole of said adapter 4 as shown in FIGS. 1 and 3.

Said

hydraulic cylinders

3a, 3b, 3c and 3d constitute a fixing means for the product with said adapter 4, and they are fixed on the swinging board 2 at upper, lower, right hand and left hand parts of its surface. All of their

pistons

9a, 9b, 9c and 9d are initially open at their outer ends, but when the adapter 4 into which the outer end 8d is forcibly placed between four pistons, and oil pressure is applied to hydraulic cylinders from the outside, the center of said adapter 4 is forcibly aligned with the axis of the auxiliary shaft 6, and all the pistons then automatically stop to advance. The outer diameter of the adapter 4, the length of the

pistons

9a, 9b, 9c and 9d, the stroke length of the

hydraulic cylinders

3a, 3b, 3c and 3d, and the positions of the fixing supports 5a and 5b are determined in order to be able to achieve the abovementioned function. The circle of the chain line in FIG. 3 shows the range of maximum movement by upwards, downwards, Iefthanded, and righthanded motion of the adapter due to the existence of deformation in the outer end 8d of the slender metallic product 8.

The center of the righthand surface of the swinging board 2 is engaged with a swinging pin through a bearing 11, the righthand part 12 of the swinging board 2 is engaged with a groove 13 formed between the end wall of the swing motion creating means 1 and the left side wall 14, and the central groove 15 provided at the periphery of said swinging board 2 is engaged with said left side wall 14. Said left side wall 14 consists of two up and down divided semi-circular rings 14a, 14b, and both rings 14a and 14b are individually engaged with said central groove 15, and subsequently they are fixed by means of screws 16.

In FIG. 1, numeral 17 shows a switch, and 18 represents an electric motor. The switch 17 is of the type of an automatic control system, and able to rotate the motor in one direction for a fixed duration and to rotate automatically in the reverse direction and to stop automatically its rotation after a fixed time. Since it is necessary to absorb rapidly the inertia of the motor, said motor 18 may preferably be a strong braking motor.

Referring now to FIG. 2, an input shaft 19 connected with said motor 18 is mounted on radial and

thrust bearings

20 and 21 on the right side wall 22 and the central wall 23 of the swing motion creating means 1, and has two

gears

24, 25 keyed thereon. The auxiliary shaft 6 is mounted on a bearing 26 at its right end, and passed through the center of the main shaft 27 by its mid-part, and the left end of the auxiliary shaft 6 is supported by a bearing 35b provided at the inside periphery of said main shaft 27. Said auxiliary shaft 6 also has a safety clutch 28 and a gear 30 clutched thereon. The gear 30 of the safety clutch 28 is meshed with said gear 24 and has gear teeth, the number of which is one less than the number of gear teeth of said gear 24, and it is supported by a bearing 31 on said auxiliary shaft 6. Said safety clutch 28 and the gear 30 are conventionally constructed with a push board 32, a spring 33 and a friction disc 34. The right end of the main shaft 27 is supported with a bearing 35a on the mid-wall 23, and the left end ofit is supported on the auxiliary shaft 6 via a bearing 35b, and a gear 36 meshed with said gear 25 and a disc plate 37 are keyed on the shaft 27, the number of the teeth of said gear 36 being the same number of teeth of the gear 25. The right end of an operating disc 38 is fixed to said disc plate 37 by means of screws, and the left end of it is supported with a bearing 39 at the left inner edge of said swing motion creating means 1, so that this results in that the left end of the main shaft 27 is supported by the bearing 39 through the disc plate 37 and the operating disc 38 on the left side of said means 1. In said operating disc 38, the operating rod 40 is supported by means of

bearings

41, 41, and a shaft 42 of a segment gear 43 is supported with

bearings

44, 44. The operating rod 40 is provided with

gears

45, 46 keyed thereon, the number of teeth of said gears being less than that of the gear 29 keyed on auxiliary shaft 6. The shaft 42 of the segment gear 43 is keyed on said gear 43, which being meshed with the gear 46, has a radius which is greater than that of the gear 46. As shown in FIG. 6, the segment gear 43 is fixedly provided with the swinging pin 10 on the center line of the auxiliary shaft 6, and a right end notch 43a is adapted to engage with a right stop 47 for the segment gear 43 fixed on the operating disc 38 and a left end notch 43b is adapted to engage with a left stop 48 for the segment gear 43 fixed on the operating disc 38.

As shown in FIG. 3, the swinging board 2 is provided at its down and left side with a yoke 49 being provided with an elongated hole 50 which is adapted to engage with a stop pin 51 set up on the frame of the swing motion creating means 1.

Now, the process of the correcting operation effected by the apparatus which is constructed in such a manner as has been previously described is as follows;

The outer end 8d of the slender metallic product 8 is forcibly inserted into the adapter 4,

standard points

80, 8b in design of the slender metallic product 8 are fixed on defined positions of the fixing

support

50, 5b respectively, by operating the

hydraulic cylinders

7a, 7b, and the four

hydraulic cylinders

30, 3b, 3c and 3d are applied with hydraulic pressure at their end so that the center of said adapter 4 is forced to be aligned with the center line of said auxiliary shaft 6. Then, the switch 17 is switched on, and the motor 18 rotates in one direction, accordingly, the input shaft 19, the

gears

25 and 36, the main shaft 27, the disc plate 37 and the operating disc 38 are rotated in one direction driven by the motor and at the same time, the gear 24, the safety clutch gear 30, the friction disc 34, the push board 32, the safety clutch 28, the auxiliary shaft 6, the gear 29, the gear 45, the gear 46 and the segment gear 43 are also rotated.

In this preferable embodiment, the gear 25 has 60 teeth, the gear 36 has 60 teeth, the gear 24 has 73 teeth, the safety clutch gear 30 has 72 teeth, the gear 29 has 24 teeth, the gear 45 has 12 teeth, the gear 46 has 11 teeth, and the segment gear 43 has 22 teeth. Viewing the apparatus from the left side of FIG. 2, when the input shaft 19 rotates clockwise 360, then the operating disc 38 rotates counterclockwise 360, and the auxiliary shaft 6 rotates counterclockwise 365. If assuming that only the operating disc 38 rotates counterclockwise 360, and the auxiliary shaft 6 and the gear 29 do not rotate, the operating rod 40 and the shaft 42 of the segment gear 43 revolve round the shaft 6 counterclockwise 360, while the gear 45 moves twice around the periphery of the gear 29 which is stationary. Accordingly, the gear 46 and the operating rod 40 will rotate counterclockwise 720, and the segment gear 43 and its shaft 42 will rotate 360. Then, fixing the operating disc 38 at the position as it is, and rotating the auxiliary shaft 6 counterclockwise 365, the segment gear 43 rotates counterclockwise 365 via the gear 29, the gear 45 and the gear 46. That is, if the operating disc 38 rotates 360 and the auxiliary shaft 6 rotates 365 counterclockwise at the same time, the segment gear 43 will rotate counterclockwise by 5. The center of swinging pin 10 fixed on said segment gear 43 is initially on the center line of the auxiliary shaft 6, that is, on the center of rotation of the operating disc 38, said swinging pin 10 rotates by 5 every time that the input shaft 19 rotates clockwise one revolution.

FIG. 7 shows the situation changed from that shown in FIG. 6, and in which the input shaft 19 rotates clockwise 180", and the operating disc 38 rotates counterclockwise 180, then the center of the swinging pin 10 which is initially at 38a on the two points chain line, comes to 38b on the chain line after its rotation in 2.5. However, after the center of said swinging pin 10 is based and located at 38b, if the operating board 38 rotates, the swinging pin 10 revolves counterclockwise round the axis of the auxiliary shaft 6 with a radius of rotation of the length of a distance between 38a and 38b. And with the progress of the clockwise rotation of the input shaft 19, the radius of revolution of the swinging pin increases gradually. In the embodiment represented, the maximum biased quantity of swing motion required to correct deformation, that is, the maximum quantity of excursion of the swinging pin 10 is 5 mm, and this value corresponds to a 50 rotation of the excursion angle of the segment disc 43. Accordingly, when the input shaft 19 rotates clockwise ten times and the excursion angle of the segment gear 43 grows into 50, and the swinging pin 10 has been displaced to the left by 5 mm, the switch 17 operates and reverses the rotation of the motor 18. If the input shaft 19 rotates counterclockwise, the segment gear 43 and the swinging pin 10 rotate clockwise in the opposite direction of that abovementioned, and when the input shaft 19 rotates counterclockwise 10 times, the center of the swinging pin 10 returns to 38a, and the switch 17 automatically stops the motor 18, and at that time the right end notch 43a of the segment gear 43 engages with the right stop 47 for the segment gear and said segment gear 43 stops its rotation. In case the operation of the switch 17 is not sufficient and the motor 18 does not reversibly rotate even if the left notch 43b engages with the left stop 48 for the segment gear and the rotation of the segment gear 43 is stopped, the friction disc 34 of the safety clutch 28 slides and the auxiliary shaft 6 stops its rotation, whereby the swinging pin 10 continues to revolve together with the operating disc 38 with a radius of the greatest quantity of the excursion. In case the operation of the switch 17 is not sufficient and the motor 18 does not still stop rotating even if the right notch 43a of the segment gear engaged with the right stop 47 for the segment gear and the rotation of said segment gear is stopped, the friction disc 34 of the safety clutch slides whereby it stops the rotation of the auxiliary shaft 6, while the main shaft 27 and the operating disc 38 is still rotating, but at this time as the swinging pin 10 is situated at the center of the rotation of the operating disc 38, it merely rotates and does not revolve. As abovementioned, the swinging pin 10 firstly revolves counterclockwise with the radius of revolution growing gradually larger, second reversing its direction of revolution, the swinging pin 10 revolves clockwise with a radius of revolution growing gradually smaller, the swinging board 2 engaged with the swinging pin 10 through the bearing 11 makes first the swing motion counterclockwise with an amplitude changing from a small quantity to a large quantity gradually, second it makes the swing motion in the opposite direction, that is, clockwise with an amplitude changing from a large quantity to a small quantity, and last it stops its revolution, its amplitude becoming zero. When the swinging board 2 makes the swing motion as abovementioned, the outer end 80' of the slender metallic product 8 which is driven into the center of the adapter 4 fitted on the swinging board 2 by four

hydraulic cylinder

3a, 3b, 3c and 3d makes the same swing motion as said swinging board 2. That is to say, first the outer end 8a is forcibly fixed in the position in which the deformation is nil, but it swings gradually from a small amplitude to a large amplitude, and subsequently it swings, in the opposite direction of the swing motion, from a large amplitude to a small amplitude, and lastly it stops its swing motion in the position in which the deformation is nil. In other words, means for gripping the slender rod are moved in a form of an involute substantially outwardly expanded to stress the slender rod beyond its elastic limit, returned in a form of an involute substantially inwardly contracted until said means for gripping reaches to the position where there is no distortion of the slender rod.

Further, regarding to the Baushinger Effect for iron and steel, which constitutes a theoretically basis utilized for the present invention, it cannot be said that it has been made clear, but is possible to draw deduction as follows;

Referring now to FIG. 8, after the outer end 8d of the slender metallic product, the center of which has firstly occupied the position represented with A, is fixed by means of the fixed support 5b and pulled down to the position represented with B by the force I over its elastic limit, when the force P is removed, the center of the outer end 8d will occupy the position represented with C because of spring back force. This quantity by elasticity depends on the internal stress of the material and the other, but it is sure that the line C is inside of the line A. In the situation of spring back, the zone (a) is a zone of expansive plastic deformation, a zone (b) is a zone of elastic deformation and has tensile stress tending to restore the rod to the original state, so that the zone (a) is subjected to the compressive stress. Similarly, zone (c) is a zone of compressive plastic deformation, zone (d) is a zone of elastic deformation and has compressive stress tending to restore the rod to the original state, so that the zone (c) is subjected to the tensile stress. Due to the balance of the internal stresses of these zones of plastic deformation and elastic deformation, the position of spring back is defined.

Then, after pulling the outer end 8d from the line C to the line D with the force Q, when the force Q is removed, the outer end 8d springs back to the line E. In such a manner, the quantity of spring back becomes smaller and smaller. Accordingly, it is possible to make the spring back zero. Of course, the position at which the spring back is zero is effected at the position at which deformation is nil.

In connection with the direction at right angles to the paper surface of FIG. 8, there is a similar function, so in this embodiment this invention achieves its object by swinging the product upwards and downwards, and from left to right.

A result of an experiment in correcting deformation is represented in FIG. 9. In FIG. 9, the metallic product which first has deformation of 0A is fixed at the point B, and then given the swing motion which is firstly small amplitude and gradually grows to large amplitude over its elastic limit, and subsequently it is subjected to positive and negative deformation from large amplitude to small amplitude, and reaches to the point C, thus the deformation of the product becomes nil.

An embodiment according to the present invention which is utilized when the deformation in straight parts, for example the center portion 8e of the straight part of said slender metallic product 8 is deformed, is represented in FIG. 10. In this embodiment, the adapter 4 is divided into two upper and lower parts, and the swinging board 2 and

hydraulic cylinders

3a, 3b, 3c and 3d are arranged in the direction of a right angle to the slender metallic product 8, and the swinging board 2 is placed under the product 8, and said swinging board 2 and

hydraulic cylinders

3a, 3b, 3c and 3d are connected with a connecting material 52.

Further, according to the present invention, torsional deformation can be corrected with the following method.

In FIG. 1, in order to correct the twist of the center point 8e for the

point

8a or 8b, the

points

8a and 8b are fixed, and by the method represented in FIG. the point Se is given the swing motion, in the upward and downward directions, and left and right movements, then the point 8e can be straightened, and at the same time, according to the same principle as represented in FIG. 8, the twist in the point 8e can be corrected. Again, in order to correct the twist deformation of the

point

80 or 8d for the

point

80 or 8b, the method described regards to FIG. 3 is applicable. As in FIG. 3 the pivot 51 set up on the frame of the swing motion creating means 1 permits the upwards and downwards motion between the swinging board 2 and the yoke 49, but does not permit the motion from left to right, so that the swing motion of the swinging board 2 becomes the motion in the upward and downward directions, and from left to right with a fulcrum of said pivot 51. If there is not a pivot 51, the position of the swinging board 2 in upper and lower, left and right position is defined the swinging pin' 10 of the operating disc 38, but its rotation is free. When first the point 8d is fixed with

hydraulic cylinder

3a, 3b, 3c and 3d, by the action of the pivot 51, said point 8d is fixed at the position at which the twist deformation of the point 8d for the point 8b is nil, while as the point 8d is upwardly bent with certain angle for the point 8b, when the swinging board 2 is counterclockwise swinging, in the upper half passage of said swing motion, the point 8d is twisted counterclockwise, and in the lower half passage of said swing motion, the point 8d is twisted clockwise. Thus, due to the same principle as represented in FIG. 8, the twist deformation can be corrected. Furthermore, as the swinging board 2 swings clockwisely after its counterclockwise swing motion, the correcting the twist deformation can be achieved effectively.

Instead of the switch 17, limit switches for automatic controlling the motor 18 may be used, such as for instance, by a limit switch provided on the fixed supports 50, 5b, and a limit switch provided on

hydraulic cylinders

7a, 7b, 3a, 3b, 3c and 3d, the motor may automatically start, and by a limit switch provided on the left stop 48 for the segment gear 43, the motor 18 may be automatically reversed, and by a limit switch provided on the right stop 47 for the segment gear 43, the motor 18 may automatically stopped.

The present invention has therefore provided an apparatus for correcting deformation of a slender metallic product which has a large correcting accuracy, is extremely efficient, and is relatively inexpensive to tool and build. in the present situation, the initial position and the final position of the swinging pin are strictly on the position where there is substantially no distortion of the slender rod. In other words, the initial position of the involute motion of the means for gripping the slender rod are strictly on the position where the distortion of the slender rod is nil, so that the accuracy of correcting distortion is very high.

Since many changes could be made in the above construction and many apparently widely differing embodiments of this invention could be made departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. Apparatus for correcting deformation of a slender metallic rod in which linear, angular, and torsional distortion exist, said apparatus comprising fixed supports to support said slender rod at at least two standard points thereof, fixing means for forcibly fixing said rod at a position where at least one of said distortions is substantially nil, a swing motion creating means to impart a swing motion to said fixing means, said swing motion comprising a swing motion in one direction growing gradually larger, and thereafter a swing motion in the opposite direction growing gradually larger, and a swinging board which is coupled to said swing motion creating means and swings upwardly and downwardly and from left to right.

2. An apparatus according to claim 1, comprising hydraulic cylinders cooperating with said fixed support.

3. An apparatus according to claim 1, wherein said fixing means comprises four hydraulic cylinders fixed on said swinging board and an adapter connected between said four cylinders adapted to hold an end of said rod.

4. An apparatus according to claim 1, wherein said swing motion creating means comprises an operating disc, a motor, an input shaft, a main shaft and a disc plate, said operating disc driven by said motor coupled through said input shaft, main shaft and disc plate, a segment gear which is provided with a swinging pin and driven by the motor through said input shaft, and an auxiliary shaft and an operating rod passed through said operating disc.

5. An apparatus according to claim 1, wherein said swinging board is integrally provided with a yoke having an elongated hole adapted to engage with a pivot set up on the frame of said swinging creating means.

6. Apparatus for correcting deformation of a slender metallic rod in which linear distortion, angular distortion and torsional distortion exist so that said distortions are reduced to nil, said apparatus comprising fixed supports,

means for supporting said slender rod at at least two standard points on the fixed supports,

holding means for forcibly holding the slender rod so that the distortions are reduced to nil, and

moving means for moving the holding means in a form of an involute substantially outwardly to stress the parts of the slender rod being held beyond their elastic limit until they reach a state of equilibrium, and then returning said holding means in a form of an involute substantially inwardly until said distortions of the slender rod become nil to overcome the inherent spring back in the slender rod.

7. Apparatus as recited in claim 6, wherein said moving means comprises:

an input shaft and a main shaft,

an operating disc which is driven by said input shaft and said main shaft,

a segment gear supported eccentrically on the operating disc,

an auxiliary shaft and a shaft of said segment gear,

said segment gear being driven by said auxiliary shaft and said shaft of the segment gear,

a swinging pin fixed on the segment gear at an extension line of the axis of the auxiliary shaft when the segmentgear is at an initial point so that the swinggear at the end of the outward involute motion of ing pin does not move in an orbit at the initial time the swinging pin, of the rotation of the main shaft and the auxiliary means f returning h input h f wh th segment shaft, gear reaches the left stop,

a plurality of gears coupling Said Segment gear to Said a swinging board which is coupled with the swinging main shaft, said segment gear, Said auxiliary h in, and and Sand Operatmg dlsc Sald gears provlded Wlth a means for gripping the slender rod which is fixed on number of teeth so that said segment gear rotates in the same direction as the direction of the rotation of the operating disc and has a larger displacement than the rotation of the operating disc, whereby the distance between the centers of the swinging pin and the operating disc grows gradually larger, said distance being an instantaneous radius of the gyration of said moving involute, hole, a right stop which sets the initial position of the segan adapter for holding an end of said rod, and

ment gear, means for gripping the outer plane of the adapter. a left stop which sets the final position of the segment the swinging board. 8. Apparatus as recited in claim 7, wherein said swinging board comprises:

a yoke which is provided with an elongated hole. a pivot which is fixed on the swing motion creating means and adapted to engage with said elongated

Claims

6. Apparatus for correcting deformation of a slender metallic rod in which linear distortion, angular distortion and torsional distortion exist so that said distortions are reduced to nil, said apparatus comprising fixed supports, means for supporting said slender rod at at least two standard points on the fixed supports, holding means for forcibly holding the slender rod so that the distortions are reduced to nil, and moving means for moving the holding means in a form of an involute substantially outwardly to stress the parts of the slender rod being held beyond their elastic limit until they reach a state of equilibrium, and then returning said holding means in a form of an involute substantially inwardly until said distortions of the slender rod become nil to overcome the inherent spring back in the slender rod.

7. Apparatus as recited in claim 6, wherein said moving means comprises: an input shaft and a main shaft, an operating disc which is driven by said input shaft and said main shaft, a segment gear supported eccentrically on the operating disc, an auxiliary shaft and a shaft of said segment gear, said segment gear being driven by said auxiliary shaft and said shaft of the segment gear, a swinging pin fixed on the segment gear at an extension line of the axis of the auxiliary shaft when the segment gear is at an initial point so that the swinging pin does not move in an orbit at the initial time of the rotation of the main shaft and the auxiliary shaft, a plurality of gears coupling said segment gear to said main shaft, said segment gear, said auxiliary shaft, and said operating disc, said gears provided with a number of teeth so that said segment gear rotates in the same direction as the direction of the rotation of the operating disc and has a larger displacement than the rotation of the operating disc, whereby the distance between the centers of the swinging pin and the operating disc grows gradually larger, said distance being an instantaneous radius of the gyration of said moving involute, a right stop which sets the initial position of the segment gear, a left stop which sets the final position of the segment gear at the end of the outward involute motion of the swinging pin, means for returning the input shaft when the segment gear reaches the left stop, a swinging board which is coupled with the swinging pin, and means for gripping the slender rod which is fixed on the swinging board.