US3653240A

US3653240A - Apparatus for manufacture of tubular projectiles

Info

Publication number: US3653240A
Application number: US803337*A
Authority: US
Inventors: Charles K Huthsing Jr
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-02-28
Filing date: 1969-02-28
Publication date: 1972-04-04
Anticipated expiration: 1989-04-04

Abstract

A plurality of tubular projectiles for use as fire extinguisher casings are simultaneously provided from a single piece of hollow cylindrical stock by techniques which involve rotating the cylindrical stock about its longitudinal axis and spinning the stock material inwardly at a point longitudinally central of each pair of projectiles to be provided while axially loading the stock to provide uniform thickness of material in the spinning area. The tubular stock is rotatably supported by formed mandrel apparatus in cooperation with a plurality of fluid operated actuators and material spinning is provided around the formed mandrel apparatus located within the hollow stock by a pair of rollers acting as another mandrel and having surfaces which conform to the formed surfaces of the interior mandrel apparatus, the rollers being movable over arcuate paths at the ends of a scissors apparatus which is also operated by a fluid controlled actuator. One end of a casing is closed by hot spinning or welding techniques and the formed end of a casing has a valve affixed thereto and the casing is charged to provide a fire extinguisher.

Description

United States Patent Huthsing, J r., deceased 1 Apr. 4, 1972 Charles K. Huthsing, Jr., deceased, late of Libertyville, III. by Evelyn N. l-luthsing, executrix [22] Filed: Feb. 28, 1969 [21] Appl.No.: 803,337

[72] inventor:

Primary Examiner--Frank T. Yost Attorney-Hill, Sherman, Meroni, Gross & Simpson [57] ABSTRACT A plurality of tubular projectiles for use as fire extinguisher casings are simultaneously provided from a single piece of hollow cylindrical stock by techniques which involve rotating the cylindrical stock about its longitudinal axis and spinning the stock material inwardly at a point longitudinally central of each pair of projectiles to be provided while axially loading [52] U.S.Cl ..72/82, 29/1.2l, 113/ 120T the stock to provide uniform thickness of material in the [51] Int. Cl ..B2ld 22/14 spinning area. The tubular stock is rotatably supported by [58] Field of Search ..29/ 1.21; 72/82, 83; 113/ 120'! formed n re ppa in oop ration with a plurality of fluid operated actuators and material spinning is provided 56] Ref en Ci around the formed mandrel apparatus located within the hollow stock by a pair of rollers acting as another mandrel and UNITED STATES PATENTS having surfaces which conform to the formed surfaces of the interior mandrel apparatus, the rollers being movable over ar- 5Ol547 7/1893 Thomson 2 cuate paths at the ends of a scissors apparatus which is also 757,432 4/ 1904 Bates ..7 operated by a fluid controlled actuator. One end of a casing is 1353982 9/1920 Bally et 29/121 X closed by hot spinning or welding techniques and the formed 81 4/1928 "72/82 X end of a casing has a valve affixed thereto and the casing is 2,030,818 2/ 1936 Harter.... .....29/ l .21 X charged to provide a fire extinguishen 3,299,680 l/l967 Thompson ..72/82 X 7 Claims, 11 Drawing Figures PATENTEDA R 4 I912 SHEET 3 UF 4 MNn www

J TIIA NW m m PATENTEDAPR 41912 3.653240 SHEET U 0F 4 APPARATUS FOR MANUFACTURE OF TUBULAR PROJECTILES BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to the manufacture of tubular projectiles and is particularly concerned with the method of an apparatus for providing a plurality of tubular projectiles simultaneously from a single piece of cylindrical stock and the provision of fire extinguishers by the method and apparatus by which a plurality of fire extinguisher casings are provided simultaneously by spin forming techniques.

2. Description of the Prior Art Heretofore, the manufacture of a plurality of like tubular projectiles generally included cutting a plurality of hollow cylinders from tubular stock and individually forming the ends of the cylinders to the desired configurations. For each cylinder there was required a separate forming step for each area of the cylinder which had a different formed configuration. It is therefore desirable in the manufacture of a large number of such formed tubular members that the number of steps per member be decreased to a minimum. In contrast to prior art techniques, the present invention provides for a decrease in the number of operations in forming tubular projectiles to the desired shape by at least one forming step for each two projectiles.

SUMMARY OF THE INVENTION Briefly, according to the present invention, a plurality of like tubular projectiles are simultaneously formed to their desired shapes by a material spinning technique which comprises rotatably supporting an elongate piece of tubular stock on a mandrel having formed surfaces which partially define the desired shape of the projectile, rotating the tubular stock about its longitudinal axis, applying a radial loading on the tubular stock in the area of the formed mandrels by wheels having formed surfaces which cooperate with the surfaces of the mandrel to define the desired shape of the projectiles, and simultaneously loading the rotating tubular stock along its longitudinal axis so that the section of the stock being formed between the formed mandrel and the formed rollers is maintained at a uniform thickness. The resulting symmetrically shaped tubular elements are separated for further processing to form a pair of fire extinguisher casings, the formed end being provided with an internal thread for engaging a fire extinguisher valve assembly and the other end being subjected to a step or a plurality of steps wherein it is closed and sealed.

The closing and sealing of the unformed end being provided by an end closure which is welded to the body, or by a hot spinning process which closes the end of the body. After the fire extinguisher body has been so formed, the extinguisher is then charged.

It is therefore the primary object of the invention to provide new and improved techniques for the manufacture of tubular projectiles.

Another object of the invention is to provide a new method and apparatus for forming a plurality of tubular projectiles simultaneously.

It is yet another object of the invention to provide new and improved methods and apparatus for the manufacture of tubular projectiles employing material spin forming techniques.

Still another object of the invention is to provide new and improved methods and apparatus for manufacturing fire extinguishers.

Yet another object of the invention is to provide new and improved methods and apparatus for manufacturing fire extinguishers by material spin forming techniques including hot spinning to close the open end of a tube.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects and features of the invention, its organization, construction and operation will be best understood from the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a side elevational view in fragmentary section, of a pair of symmetrical tubular projectiles simultaneously fonned from a single piece of tubular stock in accordance with the principles of the present invention;

FIG. 2 is a sectional view of one of the projectiles of FIG. 1 after its separation from the other such projectile;

FIG. 3 is a sectional view of the apparatus of FIG. 2 as it appears upon receiving the threads at one end thereof and which has been hot spun for closure at the other end thereof;

FIG. 4 is a view similar to FIG. 3 showing the attachment of a valve to the fire extinguisher body and the further processing of the hot spun end of the body, the cylinder being in a charged condition;

FIG. 5 shows an alternate form of a fire extinguisher wherein the end is closed by welding techniques;

FIG. 6 is an elevational view of a machine for forming the structure shown in FIG. 1;

FIG. 7 is a top plan view of the apparatus of FIG. 6;

FIG. 8 is an end view of the apparatus shown in FIG. 6;

FIG. 9 is an operational diagrammatic representation of the apparatus illustrated in FIGS. 6-8;

FIG. 10 is a fragmentary view of a portion of the apparatus shown in FIG. 6, but in greater detail; and

FIG. 11 is a view similar to FIG. 10 showing details of a portion of the apparatus of FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1 there is generally shown at 10 a pair of identically formed, and still joined, tubular projectiles 19 and 20 which are defined by wall 11 and the spun formed wall portions 12- 14. Illustrated in phantom and superimposed over the apparatus of the projectiles is the original shape of the tubular stock which is greater in length tha apparatus 10 by the lengths of element portions 21 and 23. Wall 11 of projectile l9 and of projectile 20 and the formed wall sections joining these projectiles define three chamber sections 15, I6 and 17. Phantom section 22 illustrates the degree of spin forming between the outer periphery of the tubular stock and the formed periphery of section 14. It will also be appreciated that the projectiles 19 and 20 are symmetrical about the longitudinal axis'of tube 10 and about the center line 18.

The two cylinders after being formed to the shape illustrated in FIG. 1 are separated and appear as shown in FIG. 2. Chamber 16 of FIG. 1 has now been reduced to one half of its size and designated as chamber 26 (the throat of the fire extinguisher) in FIG. 2. At this time end 27 of the projectile may be subjected to a finishing step in which the rough edges are finished smooth. Also at this time any rough edges on end 24 may be finished smooth as determined by further steps of processing. For example, if the projectile 19 of FIG. 2 is to be processed as shown in FIG. 3, such rough edges need not be removed at this time.

The projectile illustrated in FIG. 3 shows the results of a hot spinning step wherein the end 24 of FIG. 2 is heated to approximately 2,000 F. and the projectile is hot spun to a closed spherical surface as referenced at 29. The projectile is then placed in a press while still hot and end 29 is pressed inwardly to form the shape 30 having edge 31 as shown in FIG. 4. After the projectile or casing has been so formed, a valve assembly 32 is fixed thereto at 27 and the extinguisher is charged, character 15a symbolizing charging of the chamber.

As an alternative to hot spinning and pressing to form end 24 into shape 29 and then shape 30 as discussed above, end 24 may have a plate 33 of a diameter substantially equal to the internal diameter of the projectiles as shown in FIG. 5. Plate 33 includes an outwardly curved section 34 and an annular ridge 35 on its outer periphery which lies adjacent end 24. Plate 33 is then welded as shown at 36 to sealingly affix plate 33 to casing wall 11. At this time any rough edges may be finished at end 24, ridge 35 and weld 36. The projectile is then provided with a valve assembly and charged as discussed in regard to FIG. 4.

With the foregoing in mind, and referring now to FIGS. 6-11, there is illustrated apparatus for providing the symmetrical connected projectile structures of FIG. 1.

The apparatus is generally shown at 100 as comprising a frame 101 having a pair of

rails

102 and 103 which are supported by a plurality of leg structures 104, 105, 106 and 107 which are in turn joined by members 108, 109 and 110 to support the frame on a surface 111. Carried by the frame are a plurality of fluid operated (hydraulic or air) actuator devices. These devices are: actuator 120 having mounting apparatus 121 and an extensible piston rod 122; actuator 130 including mounting apparatus 131 and a hollow extensible piston rod 132; actuator 140 including mounting apparatus 141 and having a hollow extensible piston rod 142; actuator 150 including mounting apparatus 151 and an extensible piston rod 152; actuator 160 having mounting means 161 and an extensible piston rod 162; and another actuator similar to actuator 160, but not shown in the drawings.

Also shown in the drawings is formed mandrel apparatus including a shaft 172 which extends through the hollow extensible piston rod 132 and a similar shaft 182 which extends through the hollow extensible piston rod 142 into the working area 200. Shaft 182 is connected to extensible piston rod 162 of actuator 160 by way of linkage 181. Similarly, shaft 172 is connected by way of linkage 171 to the counterpart of actuator 160.

Generally speaking, a piece of tubular stock is placed in the working area 200 and rotatably secured in place by a plurality of rollers 236-239 which are part of the stock holding apparatus 226. Apparatus 226 includes a pair of spaced-apart side plates 227 having arcuate sections 228 in general conformity to the diameter of the stock, side plates 227 being joined by rods 229 and 230 and pivotally joumalled at rod 231 having a locking notch 235 therein. As apparatus 236 is pivoted to an upright working position, locking apparatus 232 having a handle 233 and a pin 234 which is biased inwardly by a spring 234 operates to engage pin 234 in notch 235. To remove the formed joined projectiles from the machine 100, handle 233 is pulled against the biasing of the spring 234 to release pin 234 from notch 235 and free apparatus 226 for rotation about rod 231.

With the tubular stock locked in operational position by apparatus 226 the proper switches 194 of controller 193 are actuated and actuator 160 and its unshown counterpart operate to position the two halves of the mandrel apparatus in engagement within the tubular stock. Mandrel 180 includes a formed head 185 which is extensible by way of shaft 182 into the working area. Likewise, shaft 172 carries a similar formed head 185a into the working area from the opposite direction. Head 185a has attached thereto a projecting pin 203 to aid in defining the completed form of the joined projectiles and which is positioned within bore 202 of head 185. Upon complete engagement of the mandrel heads 185, 185a actuators 120 and 150 are operated to lock the respective mandrel shafts 172 and 182 into their forward extended positions, for example shaft 182 includes a notch 183 therein for receiving the end of piston rod 152 of actuator 150. The same is true with respect to actuator 120 and mandrel shaft 172.

After the mandrels are locked in operating position,

actuators

130 and 140 are operated to extend their hollow piston rods 132 and 142, respectively, toward the mandrel heads. This effects a rotational locking of the tubular stock to the prime mover 190. Such engagement is efiected by a pair of arbors,for example arbor 181, which are connected to the hollow extensible piston rods 132 and 142. Arbor 181 includes a gear 183 having a portion 186 which is substantially the diameter of the tubular stock and which carries a ring of teeth 187'for engagement of the ends of the tubular stock as the arbor is moved against the stock. Arbor 181 includes a bearing 184 for joumalling a toothed shaft 198 thereto. A second gear 199 is fixed for rotation with shaft 198 and is meshed in a driving relationship with gear 183. Shaft 198 is connected in driving relationship to prime mover 190 through belt 192 and

pulleys

191 and 195. Shaft 198 also includes a section 196 for extending driving rotation to the arbor associated with actuator 130, the shaft 196 being supported by the frame at bearing 197. The mandrel heads 185 and 185a include bearings, for example bearing 201, which permits the head of the mandrels to rotate with the tubular stock without affecting rotation of the mandrel shafts 172 and 182.

After the tubular stock has been locked into an operational.

against the tubular stock. The scissor-like apparatus comprises a pair of

lever elements

214 and 215 which are spaced apart by rods 216 and pivotally connected to a cross member 218 of frame 101 at a pin 219. A similar set of elements referenced 216, 217 and 220 are pivotally connected to the frame on the opposite side of the machine. A fluid operated actuator 210 having an extensible piston rod 212 is pivotally connected to the aforementioned spaced-apart levers by

pins

211 and 213. The levers have ends which extend into the working area 200 and have rotatably secured thereto rollers 221 and 222 respectively by way of the respective pins 223 and 224.

Upon reaching the desired rotational speed, actuator 210 is operated to extend its piston 212 and radially load the tubular stock by the force exerted by wheels 221 and 222. it should be noted that wheels 221 and 222 have curved surfaces 225 which conform to and help define the desired configuration of the projectile. In effect, wheels 221 and 222 provide outer forming mandrels which cooperate with the inner mandrels to define and form the desired shape of the projectiles.

Attention is invited that during the entire forming operation the actuators and maintain a constant force on the ends 24 and 25 of the tubular stock so that during the spinning process the stock is provided with a continuous axial loading thereof so that the material in the area of the mandrels is maintained at a substantially constant thickness. Accordingly, the length of the formed projectiles is less than the length of the original tubular stock, e.g., sections 21 and 23 of FIG. 1.

Upon completion of the desired deformation of the hollow tube, selected ones of switches 194 are operated so that the tube may be removed from the machine for further processing as hereinbefore set forth to provide fire extinguisher apparatus. Operation of such switches effect a termination of rotation; releasing of the latches at actuators 120 and release of the ends of the tube by the teeth 187 upon operation of

actuators

130 and 140; and withdrawal of the mandrels by actuator and its counterpart.

Although the invention has been described and illustrated by specific exemplary embodiments, many changes and modifications will become apparent to one skilled in the art. For example, one may find it advantageous to maintain the prime mover operative and provide a clutch arrangement disposed between the prime mover and the driver arbors; however, such changes and modifications should be included within the spirit and scope of the invention as defined in the appended claims.

The embodiments of the invention in which an exclusive property of privilege is claimed are defined as follows:

1. A machine for making tubular projectiles from a hollow cylindrical tube, comprising: a frame; means carried on said frame for rotatably supporting the hollow tube; means for rotating the hollow tube comprising a pair of fluid-operated means each including an extensible hollow shaft, a pair of toothed wheels rotatably carried by the respective hollow shafts for engaging the ends of the tube, and means for rotating said toothed wheels; first and second mandrel means carried on said frame including respective first and second extensible mandrels and means for extending said first and second mandrels into the interior of the tube; third mandrel means carried on said frame including at least one third mandrel disposed externally of the tube adjacent the extended position of said first and second mandrels; means for forcing said third mandrel against the tube section between said first and second mandrels to deform the tube section; and means for continuously urging the ends of the tube toward each other during deformation of the tube to provide a constant wall thickness of the tube in the deformed section.

2. The machine according to claim 1, wherein said first and second mandrel means each comprises an extensible shaft including a groove therein and wherein said machine further comprises first and second fluid-operated means each including extensible shaft means for engagement with the respective groove for releasably latching said shafts in their extended positions.

3. The machine according to claim 1, wherein said means for rotatably supporting the tube comprises arcuate-shaped means pivotally carried on said frame for receiving the tube, first wheels carried by said arcuate-shaped means, second wheels carried by said frame, the tube being placed in rotatable engagement with said first and second wheels when said arcuate-shaped means is pivoted to place the tube in a working position, and means for releasably latching said arcuateshaped means at the working position of the tube.

4. A machine for making tubular projectiles from a hollow cylindrical tube, comprising: a frame; means carried on said frame for rotatably supporting the hollow tube; means for rotating the hollow tube; first and second mandrel means carried on said frame including respective first and second extensible mandrels and means for extending said first and second mandrels into the interior of the tube, said first and second mandrel means each comprising an extensible shaft mounted on said frame for reciprocal movement; and a formed mandrel head rotatably carried by its respective shaft, said first formed head including a pin which extends toward the second formed head, and said second formed head including a bore therein for receiving said pin when said shafts are extended, said first and second heads and said pin defining the desired inner form of said tube; third mandrel means carried on said frame including at least one third mandrel disposed externally of the tube adjacent the extended position of said first and second mandrels; means for forcing said third mandrel against the tube section between said first and second mandrels to deform the tube section; and means for continuously urging the ends of the tube toward each other during deformation of the tube to provide a constant wall thickness of the tube in the deformed section.

5. The machine according to claim 4, wherein said third mandrel includes a shaped surface which conforms to the shape defined by said first and second heads and said pin.

6. A machine for making tubular projectiles from a hollow cylindrical tube comprising: a frame; means carried on said frame for rotatably supporting the hollow tube; a pair of first fluid-operated means carried on said frame, each of said first fluid-operated means including a hollow extensible shaft directed toward the hollow extensible shah of the other and a hollow toothed wheel rotatably secured to the hollow shaft, the ends of the tube being engaged by the teeth of the wheels for mutual rotation therewith; means for rotating said tooth wheels; a pair of mandrels carried on said frame with their axes in co-axial alignment with the longitudinal axis of the tube and each of said mandrels directed toward the other and extending through respective ones of said hollow shafts and toothed wheels, and including a shaft mounted for reciprocal movement along its axis, a formed head and means for cooperable engagement of said heads; a pair of second fluidoperated actuators carried by said frame and including respective extensible shafts individually connected to separate ones of said mandrel shafts for reciprocal movement of said mandrel shafts; means for releasably latching said first and second mandrel shafts with their respective heads positioned adjacent one another within the tube; and means forming a third mandrel adjacent said first and second mandrel heads on the exterior of the tube carried by said frame, said third mandrel forming means including a pair of lever means pivotally connected to said frame, at least one wheel rotatably carried by each of said level means with the axis of rotation of the wheels being generally parallel to the longitudinal axis of the tube, and means for pivoting said lever means and forcing said wheels against the rotating tube to spin from the material in the contacted area into a shape defined by said first and second heads and said wheels.

7. A machine for making tubular projectiles from a hollow cylindrical tube according to claim 6 wherein said means for pivoting said lever means comprises third fluid-operated means including a body section connected to one of said lever means and a shaft extensible from said body second connected to the other of said lever means to operated said lever means in a scissor-like manner.

Claims

3. The machine according to claim 1, wherein said means for rotatably supporting the tube comprises arcuate-shaped means pivotally carried on said frame for receiving the tube, first wheels carried by said arcuate-shaped means, second wheels carried by said frame, the tube being placed in rotatable engagement with said first and second wheels when said arcuate-shaped means is pivoted to place the tube in a working position, and means for releasably latching said arcuate-shaped means at the working position of the tube.

6. A machine for making tubular projectiles from a hollow cylindrical tube comprising: a frame; means carried on said frame for rotatably supporting the hollow tube; a pair of first fluid-operated means carried on said frame, each of said first fluid-operated means including a hollow extensible shaft directed toward the hollow extensible shaft of the other and a hollow toothed wheel rotatably secured to the hollow shaft, the ends of the tube being engaged by the teeth of the wheels for mutual rotation therewith; means for rotating said tooth wheels; a pair of mandrels carried on said frame with their axes in co-axial alignment with the longitudinal axis of the tube and each of said mandrels directed toward the other and extending through respective ones of said hollow shafts and toothed wheels, and including a shaft mounted for reciprocal movement along its axis, a formed head and means for cooperable engagement of said heads; a pair of second fluid-operated actuators carried by said frame and including respective extensible shafts individually connected to separate ones of said mandrel shafts for reciprocal movement of said mandrel shafts; means for releasably latching said first and second mandrel shafts with their respective heads positioned adjacent one another within the tube; and means forming a third mandrel adjacent said first and second mandrel heads on the exterior of the tube carried by said frame, said third mandrel forming means including a pair of lever means pivotally connected to said frame, at least one wheel rotatably carried by each of said level means with the axis of rotation of the wheels being generally parallel to the longitudinal axis of the tube, and means for pivoting said lever means and forcing said wheels against the rotating tube to spin from the material in the contacted area into a shape defined by said first and second heads and said wheels.