US2208958A - Apparatus for bending vitreous tubing - Google Patents

Description

y- 1940- c. A. BROWN ET AL 3, 58

I APPARATUS FOR BEIIDIIIG VITREOUS TUBING VIZ/22% 2 Sheets-Sheet 1 Filed Nov. 18, 1937 m w .K n n 1 r M J V BAG, rmflkwww i w flvy Pb m8. 3 an R 2 Sheets-Sheet C. A. BROWN ET AL APPARATUS FOR BENDING VITREOUS TUBING Filed Nov.'l8, 1957 Brown, VanSickle V Inventors Car-l A. FPahk B.

Th Attorney.

July 23, 1940.

' Patented July 23, 1940 APPARATUS FOR BENDING VITREOUS TUBING Carl A. Brown, Chardon, and Frank B. Van Sickle, Lyndhurst, Ohio, assignors to General Electric Company, a corporation of New York Application November 18, 1937, Serial No. 175,196

10 Claims.

Our invention relates to apparatus for bending vitreous tubing or rods and more particularly to a machine for automatically bending short lengths of vitreous tubing or rods to a desired curvature.

Heretofore it has been the practice to bend vitreous tubing and rods manually with the assist:- ance of tools which usually consisted of a form, means for heating the tubing and perhaps tools for bending the tubing around the form. A very high degree of skill was required by the Worker and the operation was very slow and so costly as to prohibit the use of curved tubing for envelops for incandescent lamps and most types of discharge lamps.

The principal object of our invention is to increase the speed and lower the cost of bending both vitreous rod and vitreous tubing by providing an entirely automatic machine for this purpose. Another object of our invention is to increase the uniformity of the bent rod or tubing.

tube bending machine comprising our invention with transverse sections removed therefrom to reduce the length of the drawing; Fig. 2 is a plan view thereof; Fig. 3 is a section along line 3-3 of Fig. 2 in the direction indicated; Fig. 4 is a vertical section along line 44- of Fig. 2 on an enlarged scale and with portions removed as indicated and the remaining parts moved nearer together; and Fig. 5 is a piping diagram with'all apparatus therein shown in section.

The machine shown in the drawing simultaneously operates on two lengths of vitreous tubing I0 which are automatically fed from storage racks II at the middle and on opposite sides of the machine. A tube I0 is taken from each rack H at the same instant and is placed before the end of one of the spindles I2-l2 which are at that instant located farther to the right than shown in Figs. l and 2. Each spindle I2 is moved to the left and passes into the interior of a tube H] which is then released by its supporting means and is carried on said spindle l2 into the furnace or oven l3. The spindle l2 advances the tube I!) slowly through the furnace l3 so that the said tube is heated and softened before its end is in- 50 serted between the rollers I l-15 and the roll H6. The spindle I2 is then returned and the rotation of roll l6 carries the remainder of the tube l0 past the rollers I l-l5 which bend it to the curvature of said roll. After an interval of time during which it cools down, the tube is carried to the disof the four corners of the carriage.

charge conveyor belt I? located below saidroll 86 (Fig. 1). The machine is somewhat longer than shown and has sufficient structure to permit carriage l8 on which both spindles ii are mounted to move the required distance. The movement 5 of'the carriage l8 controls the operations of-the other portions of the machine which are controlled by' means located along the path thereof and engaged bysaid carriage. The path of movement of the'carriage I8 is along a.track formed 10 by the channeled bars l9 and 20 which are engaged by the rollers 2|, 22 and 23 (Fig. 4) at each The rollers 2| and 22 engage the top and bottoms of the channels in the bars 19 and 20 to hold the caris riage l8 vertically in position and the rollers 23 engage the sides thereof to hold said carriage IS in proper alignment.

In each instance, the tube l0 rests upon the inclined rails 24 of a rack N (Fig. 3) and is pre-.- 20

vented from shifting longitudinally thereof by the end plates 25 attached thereto. The inclined position 'of the rails 24 causes one of the tubes I0 in the rack II to roll into corresponding notches of a pair of wheels 26 on a shaft 21 which feed 25- a single tube Ill at intervals by a 90 rotation thereof. The teeth in the wheels 26 are only long enough to catch the particular tube Ill resting thereagainst and lift it up over the top of said wheels 26 where it rolls down the backs of thepre- 30 ceding teeth thereon and onto the upper edges of the vertically disposed plates 28 and 29 located adjacent the ends of rack H. The said plates are shown in lowered position in Fig. 1. The wheels 26 are turned by the final movement 35 of the carriage l 8 in the preceding cycle of operation during which it travels to the right and carrice the finger 30 (Figs. 2 and 4) against one ofthe teeth of the wheel 3| (Fig. 2). The finger 30 pushes the tooth engaged by it back, causing the wheel 3| and shaft 32 on which said wheel 3| is mounted to be turned slightly before the motion of carriage I8 is terminated. The shaft 32 is supported by a bracket 33 extending from each of the'bars l9 and 20 and is provided with bevel gears 34 on opposite ends thereof which mesh with the bevel gears 35 on the ends of both shafts 21. The shafts 21 are supported by the brackets 36 attached to the bars l9 and 20. 'Asshown in Figs. 2 and 4, the finger 30 is fastened to the pin 31 which is mounted in the bearing 38 on the bracket 33 extending from the carriage I8 and is prevented from turning in a counterclockwise direction by the portion of bearing '38 joining its ends. A torsion spring 40 has its ends hooked in holes in the pin 31 and the bearing 38 and allows the finger 39 and pin 31 to be turned back by the teeth on wheel 3| when the carriage I6 moves in the opposite (forward) direction. The rotation of the wheels 26 is limited to 90 degrees by a pin 4| (Figs. 1 and 3) which drops a corresponding movement of a piston 45 in a cylinder 46 (Figs. 1, 2 and.5) to which the carriage I8 is connected'by rod 41, and results from the entrance of a liquid, preferably oil, into the right hand end of said cylinder 46. The liquid is forced into said cylinder 46 from a storage tank 48 by air introduced in said tank 48 through a piston valve 49 and pipe 59 and passes through valves 5| and 52 which control the rate of flow. At this time, a piston 53 (Fig. 5) in valve 49 is in the position shown and the compressed air is introduced therein from a source (not shown) through pipe 54 (Figs. land 2) directly on top of the outer casing 55 thereof. From the pipe 54, the air passes into the longitudinal groove 56 in the top of the piston 53 which conducts it to the angular passage 51 therein in alignment with a holein the casing 55 leading to pipe 59. The movement of the carriage I8 is fairly rapid at this time since the hollow cores 58 in valves 5| and 52 are turned so that the wider portion of the V slots 58 therein are opposite the openings in the bodies 59 which are both connected to the cylinder 46 through pipe 69.

During the first part of. the movement of the spindles |2|2, the tubes |9-l|| are held in position by the stop plate 6| (Figs. 1 and 3) which is then located in front of the left ends thereof as shown in Fig. 3, but after spindles |2-|2 have passed into the tubes |9|9 so that in Fig, 1. The plate 65 is mounted on a transverse shaft 66 which is connected to shafts 63 by three arms 61 and a rod 66 so that a movement of plate causes corresponding movements of the supporting plates 28 and 29. The

downward movement of the plates 28, 29 and 65 stretches the spring 69 which is connected to a stationary part of the machine and one of the arms 61. The stop plate 6| is pivoted at 19 on arms extending from one pair of bearings 64 and is moved down by the pressure of a plate 1|, mounted on one of the shafts 63, thereagainst. The downward movement of the stop plate 6| stretches the spring 12 located between posts therein and in supporting plate 29.

The rapid movement of the carriage l8 continues only until the tubes Ill-l9 are completely within the furnace l3, whereupon a roller 4 gs.

therein.

2 and 3) which is attached to'the far side of the carriage l8 by means of a bracket 15 engages a cam 16. The cam 16 is connected to the core 58 of valve 5| through the shaft 11 and. when rotated by the roller 14, turns the core 58 so that flow of liquid through the valve 5| is lessened and the carriage is moved more slowly. The

speed of movement of the carriage I8 is now .such that the tubes Ill-I0 are retained, until preferably controlled automatically by means (not shown) in order to assure the most efficient operation of the machine. To facilitate a thorough and uniform heating of each of the tubes ||l|ll, the said tubes are constantly rotated by the rotation .of the spindles |2--|2 which,

as shown in Fig. 4, are each mounted on ball bearings 19 and 89 in the carriage l8 and are driven by an electric motor 8| mounted thereon.

The connection between the motor 6| and thespindles |2|2 is made through a worm gear 82 mounted on the motor shaft which meshes with gears 83 on each of the spindles. Since excessive heat can be conducted back to the bearings in the carriage l8 in some instances, the spindles |2--|2' are cooled by a flow of air in the passage 84 in each spindle which connects The temperature of the furnace'l3 is to the chamber 85 in the carriage 8 into which air is introduced through pipe 86.

By the time the forward end of each of the vitreous tubes Ill-I9 is heated sufficiently to permit bending, said end is carried between the rollers |4-|5 and the form or roll i6 by the movements of. the carriage .|8. The rollers l4 and I5 and the roll l6 are preferably made of carbon so as not to stick to the tubes Ill-I0 and are provided with semi-circular grooves in the faces thereof which conform to the exterior shape of the tubes. Once a tube l9 passes be- "tween these rollers |4|5 and the roll |6, it

is advanced by the rotation of the roll l6 which is mounted on a shaft 81 and is turne'd in a counter-clockwise direction by a pulley 88 mounted thereon. The shaft 81 is mounted in the frame 89 of the machine which also supports an electric motor 90 and speed reducer 9| which operates the pulley 98 through a belt 92 and pulley 93 on the shaft of the speed reducer 9|.

The roll I6 has a fixed relation to the roller M which is mounted on a hollow shaft 94 and is pressed down against roll l6 by springs 95 located above slide blocks 96 on the opposite ends of shaft 94. -The outer rims of the roller |4 ride in grooves 96' in the periphery of roll l6 at opposite sides of the semi-circular groove therein and does not distort the tube Ill. The slide blocks 96 are located in ways in the frame 89 and engage one end of springs 95 which are retained in the required state of compression by bolts 91. At the time the end of the tube In passes under the roller l4, the roller I5 is held in a raised position and does not contact the tubing II), but shortly thereafter said tube l0 passes below the roller l5 which is lowered so that the end of the tube is bent down into contact with roll I 6. The roller I5 is mounted on a hollow shaft98 which is supported by a lever 99 at each side of the machine and is caused to move down by a piston I09 in a cylinder ||l| which is connected to said levers 99 through a rod I02, link I03 and rod I94. The

' der 46 which pushes carriage I8 is directly responsible for the movement of the roller I5 since it reaches the limit of its movement at this time and strikes the control pin I05 of a valve I06 which causes the piston 53 within the valve 49 to shift and compressed air to pass into the cylinder IOI behind the piston I00. The carriage I8 moves the control pin I05 back into the valve I06 (Fig. 5) thereby compressing thespring I01 and opening said valve I06 so. that air is bled from the space behind the piston 53 through the pipe I08 and said valve I06. In this way, the piston 53 is shifted since the inflow of air into the space referredto through the opening I09 in said piston 53 is not suflicient to prevent the air pressure behind the other end thereof from causing it to move. 53, the compressed air passing, into the valve 49 through the pipe 54 is conducted by the groove 56 and an angular passage H in the piston 53 to the opening in the valve casing 55 leading to pipe III.- The pipe III conducts the compressed air to the cylinder IOI, which lowers the 'roller I as described, and to the forward end of cylinthe piston 45 and carriage I8 back,

In order that the piston 45 can be moved by v its forward movement, carries a roller I I4 (Fig.

2) attached to the side thereof by the bracket II4, against a cam H6. The cam H5 is connected by a rod 5' to the core 58 of the valve,

52 which is turned so that the liquid in the cylinder 46 is permitted toreturn to the storage tank 48 more rapidly than it passed therefr m.

The tube I6 is now supported solely by the rollers I4I5 and the roll I6 and is advanced therebetween by the rotation of the roll' I6 which also advances the bent or curved end under the rollers H6 and H6". The rollers II6'and 6' each have a semi-circular groove therein that conforms'to the shape of the tubing I0 and are pressed against the roll I6 so that the rims thereof ride in the grooves 96' in said roll I6 and the tubing I0 is held in place while cooling. The rollers H6 and II6"are supported by hollow shafts H1 and H8 respectively which are mounted in slide blocks H9 and I? respectively in ways of the frame 89 at both sides of the machine and are pressed against the roll "by springs HI and I22 located thereabove.

of the tubing is carried farther around with the roll I6 and'finally is engaged by the rollers I23 and I24 (Fig. 4) which hold it against roll I6 for an interval during which it is allowed to cool and is carried nearer to the discharge conveyor belt' I1. The roller I23 is supported by an arm I25 which is pivoted on a bracket I26 extending from the frame 89 of the machine, whereas roller I24 is supported by an arm I21pivotally attached to the arm I25. The rollers I28 and I24 are retained in this position only during the interval the tube I0 is advanced thereto since a followin tube I0 is then being transferred onto the plates In the new location of the piston Dur ing the rotation of the roll I6 the forward end 28 and 29 (Fig; 1) and the bar 68 which moves them into position toreceive said tubing I0 is against the control arm I28 of a valve I29. The

' valve I29 (Fig. 5) controls the flow of compressed air into the cylinder I30 behind the piston III which is connected to the arm I21 by rod I32 and which swings said arm I21 so that the rollers,

duced into the valve I29 through pipe I34 and is conducted through the passages in the valve body I35, the piston I36 and the pipe I31 to the cylinder I30. The control arm I28 of the valve I29 is pivoted in the valve body I35 and moves the piston I36 down against the lifting force of the compressed air within the passage in said piston I36. When the roll I 6 turns so far that the tube I0 is located on the lower portion thereof the rollers I23 andv I 24 are swung down and back from said roll I6 so that the tube I0 is partially carried and partially rolls down onto the conveyor belt I1. This action results from the bleeding of the compressed air from the cylinder I80 through the valve I29 which permits the weight of the arms I25 and I21 to carry the rollers I28 and I24 down and is broughtabout by the downward movement of the plate 29 with the forward movement of the carriage I8 which raises the bar 68 from the control arm I28 of the valve I28. The compressed air within the piston I86 of the valve I29 raises it when the pressure is released from thecontrol arm I28 so that a groove I36 around said piston I36 is brought into alignment with the passage in the valve body I35 leading to pipe I31 and the exhaust opening I39 in said body I35. In this way, the tube I0 is placed on the conveyor belt I1 so gently that all possibility of distortion is eliminated and the finished tube I0 is carried away from the machine by the conveyor I1. A partition I40 attached to the arm I21 prevents the tubes. I0--I0 from touching each other when they are unloaded, This partition I40 passes up into a space between the rolls I6-I6 when the rollers I28 and I24 are in the raised position.

The return movement of the carriage I8 withdrawing the'spindles I2- -I2 from the furnace I3 occursat a uniform rate until nearly the end of the stroke is reached whereupon the rollers 14 and H4 on opposite sides thereof engage cams I and I42 respectively which adjust the valves 5| and 52. The cams HI and I42 are mounted on the rods 11 and H5 which are connected to the cores 58-58 of the valves 5| and 52 and turn said cores 5858 so that the flow of liquid through valve. 5'I ,is more rapid and through valve 52 is less rapid. This'adiustment sets the speedof the forward movement of the carriage I8 which is now brought about by the striking of roller 4 thereon against valve I43. I bleeds the compressed air from the left end (Fig. 5') of the piston 53in valve 49 so that it shifts tothe p sition shown and compressed air is permitted to flow through passage 51 to the tank 48 to ac uate the carriage I8 as already described. The roller II4 engages the pin I44 of valve I48 which compre ses the spring I and separates the flanged portion of the pin I44 from its seat on the valve body I46. The air allowed to escape The valve I48 through the valve I43 passes thereto through pipe I41 and flows more rapidly from the valve casing 55 than it is permitted to flow in through the sure against the opposite end of the piston 53 causes it to shift. The air behind the left hand ,end' of the piston 45 in cylinder 46 is exhausted through pipe I I l, the transverse passage I49 in thepiston 53 and the pipe I50 as succeeding repeat operations 'of the apparatus, which have been described, are brought about.

While we have shown and described certain novel features of the invention, it will be understood that various omissions, substitutions and changes in the form. and details of the device illustrated and in its use and operation may be made by those skilled in the art withoutdeparting from the broad spirit and scope of the invention.

What we claim as new and desire to secure by LettersPatent of. the United States is: 1. Apparatus for bending vitreous tubing com prising an oven, a form having a contour of the desired shape of the tubing rotatably mounted adjacent said oven, means for-advancing the tubing into the oven to heat it to its softening temperature and for then advancing it into engagement with the form, means for pressing said tubing against said form, and means for rotating said form to carry the tubing thereon past said pressing means and to cause it to be bent to the shape of the form, the tube-engaging portions of said form and pressing means having opposed peripheral grooves of substantially the same cross sectional shape as the'tubing to prevent distortion of its cross-sectional shape during the bending operation.

2. Apparatus for bending vitreous tubing comprising an oven, a roll the curvature of the periphery of which corresponds to the desired shape of the tubing rotatably mounted adjacent said oven, means for advancing the tubing into said oven to heat it to its softening temperature and for then advancing it into engagement with said roll, a plurality of rollers located adjacent the periphery of said roll for pressing said tubing against said roll, and means for rotating said prising an oven, a roll the curvature of the periphery of which corresponds to the desired shape of the tubing rotatably mounted adjacent said oven, means for advancing the tubing into said oven to heat it to its softening temperature and for then advancing it into engagement with said roll, a plurality of rollers located adjacent theperiphery of said roll for pressing said tubing against said roll, means for rotating said roll to carry the tubing thereon past said rollers to cause it to be bent to the curvature of said roll,

and means for holding the tubing against said roll during further rotation thereof to allow said tubing to cool while it is still retained in the desired shape, the tube-engaging portions of said roll and rollers having opposed peripheral grooves of substantially the same cross-sectional shape as the tubing to prevent distortion of its crosssectional shape during the bending operation.

4. Apparatus for bending vitreous tubing comprising an oven, a form having a contour of the desired shape of the tubing rotatably mounted adjacent said oven, means for supporting the tubing adjacent said oven, aspindle adapted to enter the tubing, means for carrying said spindle v into the tubing and then further advancing it to carry said tubing into said oven to heat it to its softening temperature and then to carry an end of said tubing into engagement with said form, means for pressing said tubing into engagement with said form, and means for rotating said form to carry the tubing thereon past said pressing means and cause it to be bent to the shape of said form.

5. Apparatus for bending vitreous tubing comprising an oven, a form having a contour of the desired shape of the tubing rotatably mounted adjacent said oven, means for supporting the tubing adjacent said oven, a spindle adapted to enter the tubing, a carriage for supporting said spindle, a track for said carriage located adjacent said tubing holding means and said oven, means for moving said carriage on its track to carry the said spindle'into the tubing and then further advancing it to carry said tubing into said oven to heat it to its softening temperature and then to carry an end of said tubing into engagement with said form, means for pressing said tubing. into engagement with .said form, and means for rotating said form to carry the tubing thereon past said pressing means andcause it to be bent to the shape of the form. 6. Apparatus for bending vitreous tubing comprising an oven, a form having a contour of the desired shape of the. tubing rotatably, mounted -adjacent said oven, means forsupporting the gagement with'said form, means carried by said carriage for rotating said spindle to cause the tubing thereon to be rotated while it is in the oven, means for pressing the tubing intoengagement with said form, and meansfor rotating said form to carry the tubing thereon past said pressing means and cause it to be bent to the shape of said form. I

7. Apparatus for bending vitreous tubing comprising an oven, a form having a contour of the desired shape of the tubing rotatably mounted adjacent said oven, means for supporting the tubing adjacent said oven, a spindle adapted to enter the tubing, a carriage for supporting said spindle, a track for said carriage located adjacent said tubing holding means and said oven, means for moving said carriage on its track to carry said spindle into the tubing and 'then further advancing it to carry said tubing into said oven to heat it to its softening temperature and thento carry an end of said tubing into engagement with said form comprising a cylinder located adjacent said track and having a piston there'n attached tosaid carriage for moving it, a tank connected to one end of said cylinder and containing a liquid, and means for supplying air pressure to said tank to force liquid therefrom into said cylinder and against one side of the piston therein to advance the carriage and for supplying air pressure to the other side of, said piston to retract the carriage, means for pressing the tubing into engagement with said form, and.

means for rotating said form to carry the tubing thereon past said pressing means and cause it to be bent to the shapeof said form.

8. Apparatus for bending vitreous tubing comprising an oven, a form having a contour of the desired shape of the tubing rotatably mounted adjacent, said oveng means for supporting the tubing adjacent said oven, a spindle adapted to enter the tubing, a carriage forsupporting said spindle, a track for said carriage located adjacent said tubing holding means and said oven, means for moving said carriage on its track to carry said spindle into the tubing and then further advance it to carry said tubing into said oven to heat it to its softening temperature and then to carry an end of said tubing into engagement with said form comprising a cylinder located adjacent said track and having a piston therein attached to said carriage for moving it, a tank connected to one end of said cylinder and con taining a liquid, means for supplying air pressure to said tank to force the liquid therefrom into said cylinder andagainst one side of the piston therein to advance the carriage and for supplying air pressure to the other sideof said piston to retract the carriage, a valve connected to said tank and to said cylinder for controlling the flow of liquid therebetween and means disposed along the path of movement of said carriage and engaged thereby for adjusting the position of said valve and varying the rate of movement of the said carriage, means for pressing the tubing into engagement with said form, and means for rotating said form to carry the tubing thereon past said pressing means and cause it to be bent to the shape of said form.

9. Apparatus for bending vitreous tubing comprising an oven, a form having a contour of the desired shape of the tubing rotatably mounted adjacent said oven, means for supporting a plurality of tubings adjacent said oven, a plurality of spindles each adapted to enter one of said tubings, a carriage for supporting said spindles, a track for said carriage located adjacent said tubing holding means and said oven, means for moving said carriage on its track, to carry each of said spindles into one of said tubings and then further advance it to carry the tubing into said oven to heat it to its softening temperature and then to carry an end of the tubing into engagement with portions of said form, means for pressing tubings into engagement with said form, and means for rotating said form to carry the tubings thereon past said pressing means and cause said tubings to be bent to the shape of the form.

10. Apparatus for bending vitreous tubing comprising an oven, a plurality of rolls the curvature of the peripheries of which correspond to the desired shape of the tubing rotatably mounted adjacent said oven, means for supporting a plurality of tubings adjacent said oven, a plurality of spindles each adapted to enter one tubing, a carriagefor supporting said spindles, a track for said carriage located adjacent said tubing holding means and said oven, means for moving said carriage on its track to carry each of said spindles into a tubing and then further advance it to carry the tubing into said oven to heat it to its softening temperature and then' to carry an end of the tubing into engagement with the periphery of one of said rolls, means carried by said carriage for rotating said spindles to cause the tubings thereon to be rotated while in said oven, aplurality of rollers located adjacent the periphery of said rolls for pressing the tubings into engagement therewith, and means for rotating said rolls to carry-the tubings thereon past said rollers and cause said tubings to be bent to the curvature of said roll.

CARL A. BROWN. FRANK B. VAN SICKLE.

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