US2291803A

US2291803A - Shell banding machine

Info

Publication number: US2291803A
Application number: US369163A
Authority: US
Inventors: Carl C Grotnes
Original assignee: Individual
Current assignee: Individual
Priority date: 1940-12-09
Filing date: 1940-12-09
Publication date: 1942-08-04
Anticipated expiration: 1959-08-04

Description

c. c. GROTNES SHELL SANDING MACHINE Aug. 4, 1942.

2 Sheets-Shee t 1.

Filed Dec. 9, 1940 NvsN TQL) Oar/ C Grofnes rrowys Patented Aug. 4, 1942 UNITED srAresrerENT OFFICE 2,291,803 SHELL BANDING MACHINE Carl C. Grotnes, Park Ridge, Ill. Application December 9, 1940,.Serial No. 369,163

(c1. vs 15 4 Claims.

The invention relates to an improved machine for applying driving bands to projectiles or shells.

Shells intended for use in rifled guns are provided with one or more driving bands which, in conjunction with the rifiing of the gun, impart rotative movement to the shell in its passage through the gun bore. The band is customarily made of copper or a copper alloy known as guilding metal, and it is ordinarily pressed into an undercut peripheral groove near the base of the shell. To insure proper functioning when the shell is fired, the band must be pressed in place with sufiicient force to effect a firm binding or gripping engagement between the band and the walls of the groove, and for satisfactory results a high degree of uniformity is essential.

The application of driving bands with the shell pressing operations between each of which the shell is rotated about its longitudinal axis to present a different band area to the dies. With such machines a substantial amount of time is unnecessarily consumed, considerable skill on the force but at a decreasing rate of compression, together with means for controlling the operation so as to obtain uniformity while permitting variations in accordance with the size'of the band.

Another object is toprovide in a machine of the foregoing character, an' actuating means automatically operative to prevent compression of the band beyond a predetermined desired maximum degree.

part of the attendant is required, and the open ation is apt not to be uniform and is generally unsatisfactory. v r

A factor of primary importance in the application of driving bands to shells is the time required to insure the flow of the metal of the band as the same is being compressed into its groove. Thus, a predetermined minimum time is required for the compressing operation, varying with the size of the band i. e, the circume ference and cross sectional area thereof, more time being required as the band increases in size. Moreover, it is important that the compressing operation take place at a gradually decreasing rate but with a gradually increasing force inorder to insur that a firm gripping eny gagement between the band and the shell will be produced. Finally, a high degree of uniformity in the operation is desirable, not only to insure proper seating of the band in its groove, but

to avoid variations in hardness of the band which.

may occur as an incident to variations in the rate means for compressing the band into its receiving groove operative with a gradually increasing Another object is to provide a shell banding machine in which a set of compressing dies are actuated in the performance of the compressing operation by means of a reciprocatory actuator movable at a predetermined constant speed, through the medium of a mechanical motion transmitting connection acting to increase the effective pressure gradually up to a predetermined maximum, while simultaneously decreasing the rate of movement of the dies.

Another object is the provision of an improved shell banding machine which is faster and more accurate in operation and which requires a minimum of skill on the part of the attendant.

Another'object is to provide a shell banding machine embodying novel die actuating mechanism and controls whereby the dies may be rapidly closed upon the driving band to avoid waste of time and then advanced at an accurately con trollable rate so as to effect a gradual flow of metal of the band into all portions of the shell groove.

Other objects and advantages of the invention will become apparent from the following detailed description of the preferred embodiment illustrated in the accompanying drawings in which:

Figure 1 is a vertical sectional view of a shell banding machine embodying the features of the invention.

Fig. 2 is a fragmentary sectional view of a shell anda driving band as assembled in the machine before the band is pressed into the shell groove.

Fig. 3 is a top view of the machine with a portion broken away to show the arrangement of r the die mechanism and the actuating means therefor.

. Fig. 4 is a perspective view of one of the units forming the die mechanism.

Fig. 5 is a diagrammatic view of the hydraulic and electrical control and operating circuits of the machine.

While the invention is susceptible of various modifications and alternative constructions, I

have shown in the drawings and will herein describe in detail the preferred embodiment, but

it is to be understood that I do not thereby intend to limit the invention to the specific form disclosed but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

For purposes of illustration, the improved shell banding machine has been shown as arranged for applying a copper band 6 (Figs. 1 and 2) to a shell 1 having a single band receiving groove 8. This groove extends around the periphery of the shell closely adjacent the base portion thereof which is slightly tapered as indicated at 9. In accordance with the usual practice, the sides of the groove are under-cut as at Ill (Fig. 2) and the base I I of the groove is knurled or otherwise roughened to effectually maintain a driving ngagement between the band and the shell under all conditions. The band 6 of course, is initially formed with an internal diameter sufficient to enable-it to be slipped over the shell. It is then contracted and pressed into "the'groove 8 by "a suitable-die mechanism [2.

In carrying out the'invention, a die mechanism is employed including a'set of radially movable dies, together with an actuatihg'me'chanism comprising a reciprocatory actuator disposed axially of the dies, and'a"motion"transmitting connection including toggle links operative in the movement of the actuator to' exert a gradually increasing force upon the 'dies'. Although the actuator be moved at a predetermined constant rate, the toggle links, due to their power multiplying actionQ' automatically introduce the gradually increasing time interval necessary to the fiow of the metal in' the compressing operation.- For variationsin the'rate"of'compression rendered necessary because of 'diife rences' in the sizes of the bands," it is'only necessary to change the rate of movement of the actuator, 'a'n adjustment-which is obtainable to advantage'through the use of actuating-mechanism hydraulic in character.

In its preferred form the machine comprises a generally cylindricalbase herein shown as-consisting of upper and lower sections I3"and 14 secured together in end to end "relation as by bolts l5. Both sections are constructd'with'eX- ternal strengthening ribs l and the iipper section is formed-internally to provide aslidewa'y for a vertically reciprocatory head ll.

The'head l! carries the band. engaging portion of the die mechanism l2 which, as herein shown, comprises a'series of segmental die' block's" 20 (Figs. 1-4) each mounted on a radially movable carrier 2|. The inner ends 22 (Figs. 3 and ll of the die blocks are formed with arcuate contours on radii centered on the aXis of the head so that the blocks, in their inner position, definea 'c'ylindrical cavity having a diameter corresponding.

to that of 7 the band after it has bee i 'pressed into its groove. Anappropriately dimensioned set of dieblocks is required, of courseefor each size of shell banded in the machine. Tofacilitate wedge shaped spacers 2'! and segmental retaining plates 28 arranged in spaced relation and bolted to the face of an annular bed plate 29 (Fig. 1) carried by the head. The spacers are arranged to provide a series of substantially equally spaced radially disposed slots dimensioned to slidably receive the flanged portions of the carriers 2 l. The plates 28 are constructed so as to extend over the edges of the spacers 21 and thus overlie the sides of the slots defined by the spacers. In this position the edges of the plates act to engage the carrier flanges 25 and thus retain the carriers in the guideway.

-Each carrier is moved radially in its guideway in response to the axial reciprocation of the head ll, and for this purpose a toggle mechanism is advantageously employed. This toggle mechanism comprises as herein shown a pin 3| fastened between spaced rearwardly projecting ears 32 on the carrier block 24 and connected by a link with a pin 33 mounted on a channel shaped stationary block 34 bolted or otherwise rigidly secured'to athrust ring35 firmly anchored'to the top of the upper basesection L3; An annular plate 36 bolted to the'ring 35 engages the upper end of the stationary blocks 34jto relieve the attaching bolts of strains duetothe actuation of the toggle mechanism.

Thelink connection between the pins 3| and 33 preferably comprises -a pair oi tension links 3'! engagingthe projecting ends of the pins and a compression link '38 having semicylindrical sockets at each end engaging "thecentral portions of the respective'pins. While thelinks 31 can transmit compression as well as tension stresses, the major portion of, the compression load is carried by the links 38 which, because of their relatively large cross section, are "less susceptible to distortion under compression than thelinks3].

Suitable means is provided on the head for holding the shell 'lin an upright position concentrically' of the die'blocks 2,0, and for holding the band 6 in alinementwith the groove 8 in the shell. This means'as herein shown, comprises a cylindrical holder 49 mounted in a central recess in the head and projecting through the aperture of the bed plate 29. The holder is formed internally with a'cup-shape'dsocket adapted to receive'the base of the shell I; which as explained hereinbefore, is usually slightly tapered as shown in Fig. 1. Encircling the upper end of the holder is :a cylindrical flange -4| having-it's upper edge disposed in the same plane as the lower side wall of' the groove '8 in the shell. The band 6 when initially slipped over the shell rests on this flange as shown in Fig. 1 which is thus efiective to position the band in alinement with the groove. The outer wall'of the flange "is' recessed to provide clearance for the die blocks 21in their inward movement.

As hereinbefore indicated it is of primary importance that the bands beicompressed uniformly and at a gradually decreasingrate, withan ample time allowance to permit the flow of the metal of the band and with a predetermined maximum force sufficient to insure intere'ngagement of the metal of the band with" the roughenedsurfaceof the bottom I l for "the groove 8 In the attainment of this result I employ hydraulic'm'eaiis coacting w t T' he toggle? ii e fm; i ii i te being capable of accurate regulationsoas to impart a'uniform constant rate of ;mo vem ent to the head, "and "beinglike wisef readily adjustable with respect to the rate at which the pressure is applied.

The hydraulic means as herein shown, comprises a cylinder 44 mounted in a vertical position in the lower base section I. A head 45 closes the upper end of the cylinder. The cylinder is provided with a working piston 46 having a piston rod 41 extending upwardly through a stuiflng box 48 on the cylinder head 45 and projecting through an aperture in the top wall of the head I! for connection therewith. The connection is provided in the present instance by clamping nuts 49 and 50 threaded on the projecting end of the piston rod on opposite sides of the head, the nut 49 forming the base of the re- M. The pressure fluid is delivered to the cyl- T inder through the hydraulic circuit shown diagrammatically in Fig. 5 which includes suitable valves and other control instrumentalities for governing the operating cycle of the machine in the manner required for proper application of l the driving bands. More particularly, the controls are arranged to impart automatically first a relatively rapid movement to the head I! in which the die blocks 25 are moved quickly into engagement with the band, and then a slow compressing movement at a uniform constant speed during which the die blocks are advanced with a force gradually increasing to a predetermined maximum but at a gradually decreasing rate due to the action of the toggle mechanism.

Referring now to Fig. 5, the pump P is arranged to draw fluid from a sump or reservoir R and deliver it under pressure through a duct 5| to a reversing valve RV. A relief valve V prevents excessive pressure in the system. The reversing valve may be of any suitable and well known construction, and, in the present instance, is arranged for manual operation by means of a hand lever 52. With the valve in the position shown in Fig. 5, pressure fluid from the duct 5| is directed by way of a duct 53, normally open shut-01f valve SV, duct 54, check valve VI and duct to the lower end of the cylinder 44. The piston 45 is thus shifted upwardly and,

through the toggle mechanism, acts to close the die blocks together on the driving band and shell.

The valve SV is arranged to be closed by a solenoid S when the solenoid is energized. Current is supplied to the solenoid from any suitable source by way of line conductors L--! and L2 under control of a switch SW arranged to be actuated in timed relation to the closing of the die mechanism. As herein shown, the switch is closed at a predetermined point in upward movement of the head i! through the medium of a cam 56 conveniently mounted on the piston rod 41. The cam is preferably adjustable so that the point at which the switch is closed may be varied as required.

Upon closure of the valve SV, pressure fluid is supplied to the lower end of the cylinder 44 through a by-pass circuit including a duct 51 in which is interposed a metering or feed control valve MV which substantially reduces the volume of pressure fluid delivered to the cylinder. The valve MV is preferably manually adjustable so that the rate of feed can be varied as required.

In practice, the switch SW will be set to close substantially at the time the die blocks reach the position shown in the upper part of Fig. 3, that is, at the instant the die blocks engage the band 6. In other words, the die blocks are quickly closed on the driving band with a consequent saving in operating time. Thereafter the head is raised slowly at a uniform constant speed adjusted in accordance with the size of the band being operated upon. With the rate of movement of the head thus controlled, coupled with the gradually decreasing rate of movement of the die blocks due to the movement of the toggles from an initial inclined position substantially into dead center position, ample time is insured for the compressing operation.

The amount of pressure applied to the head is maintained at a predetermined maximum to obtain uniformity in operation by an adjustable relief valve V2 connected in a branch circuit with the duct 55 by a duct 59. This valve may be set to open at any predetermined pressure and, on opening, returns pressure fluid to the reservoir R through a drain duct 50. A pressure gauge 6| of any suitable character may be connected with the duct 59 to indicate the effective pressure on the piston 46 for the guidance of the attendant.

In the upward movement of the piston 46, spent pressure fluid is discharged from the upper end of the cylinder 44 through a drain duct 62, reversing valve RV and drain duct 65. When the reversing valve is manually operated to its alternate position, pressure fluid is directed through the duct 52 to the upper end of the cylinder, thus shifting the piston downwardly and retracting the die blocks. In order to allow quick return of the piston and avoid unnecessary delay between operations, spent pressure fluid from the lower end of the cylinder 44 is discharged through a by-pass duct 63 and reversing valve RV to the drain duct 60. A check valve V3 is interposed in this by-pass duct to direct the flow of pressure fluid through the valves SV and MV in the first part of the operating cycle.

When it is desired to operate the piston 45 through its full stroke without the'delayed action above described, the circuit for the solenoid S is temporarily disabled by means of a manually operable switch SWI'interpoSed in the line conductor L2. Under these conditions, the movements of the piston and head are under sole control of the manually operable reversing valve RV.

In the operation of the machine. the shell 1 to be banded is placed in the holder 40 while the head is in the lower or inactive position shown in Fig. 1. In this position the die blocks of course, will be fully retracted. No particular skill is required in placing the shell in the machine since the holder 4!) is arranged to position the same in correct relationship to the die mechanism. The band 6 is then slipped over the shell and allowed to rest on the upper end of the flange 4|. This serves to position the band in exact alinement with the groove 8.

The attendant may now actuate the starting lever 52 to operate the valve RV to the position shown in Fig. 5, whereupon the piston 46 and the head I! are moved upwardly at a rapid rate to close the die blocks together on the band 6.

As the die blocks reach the position shown in the upper portion of Fig. 3, that is, upon their engagement with the band, cam 56 closes the switch SW to energize the solenoid S and thus close the valve SV. The supply of pressure fluid to the cylinder is now controlled by the metering valve MV and movement of the head proceeds at a relatively slow constant rate. The die blocks however, are advanced at a gradually decreasing rate as the toggle links move from the inclined position shown in Fig. 1 substantially into horizontal or dead center position. This gradual deceleration of the die blocks prolongs the compressing operation so as to allow the necessary time for the flowage of the metal of the band. At the same time a corresponding multiplication of power is obtained to insure that the band will be forced home.

When the ring is fully seated in the groove as evidenced by the completion of the forward movement of the die blocks, an indication is given to the operator by the gauge 6| or by the'opening of the relief valve V2. The attendant may then operate the reversing valve to its alternate position and thereby return the head to its lower position which causes a retraction of the die blocks. With the die blocks retracted, the banded shell may be lifted from the holder and another shell and band placed therein for the next operation.

It will be apparent from the foregoing, that the invention provides a shell banding machine of novel and improved construction. By reason of the novel die actuating mechanism and controls therefor, the die mechanism is rapidly closed upon the driving band and then advanced at a gradually decreasing predetermined rate according to the size of the band, the maximum force finally exerted being the exact predetermined pressure required to force the band home and insure binding engagement with the bottom of the groove. Thus the band is forced firmly and accurately into the groove provided for its reception without any effort on the part of the attendant other than starting the operating cycle. The point at which the change in the rate of movement of the head takes place is determined by the setting of the machine and requires no attention On the part of the attendant. Moreover, due to the provision of a single actuator, the die blocks act uniformly on the band around its entire periphery and thus insure proper seating of the band in thegroove.

I claim as my invention;

1. A shell banding machine having, in combination, a movable head, means carried by thehead for supporting a peripherally grooved shell with a driving band in alinement with the groove, an annular diemechanismadapted to be tion valve controlling the supply of pressure fluid to said pressure fluid actuated means operable in one position to efiect a relatively rapid advance of the head and in the other position to effect a substantially slower advance of the head, a solenoid operative when energized to shift the valve from said one position to the other, and a switch actuated in timed relation to the advance of the head for energizing said solenoid substantially simultaneously with the engagement of the die mechanism with the driving band.

2. A shell banding machine having, in combination, a movable head, means carried by the head for supporting a peripherally grooved shell with a driving band in alinement with the groove, an annular die mechanism adapted to be closed on the band to press the same into the groove in the shell, actuating means for said die mechanism operable in response to the movement of the head, pressure fluid actuated means for advancing and retracting the head, a two position valve controlling the supply of pressure fluid to said pressure fluid actuated means operable in one position to' effect a relatively rapid advance of the head and in the other position to effect a substantially slower advance of the head, and means actuated incident to the reciprocation of the head for controlling the position of said valve.

3. A shell banding machine having, in combination, means for supporting a peripherally grooved shell with a driving band encircling the same and alined with the groove, die mechanism including an annular series of die blocks supported for radial movement toward and from the shell, common pressure fluid actuated means for moving all of said die blocks simultaneously toward the band, a valve controlling the supply of pressure fluid to said last means normally set to effect a rapid movement of the die blocks toward the band, and means operative automatically for resetting said valve substantially simultaneously with the engagement of the band by said die blocks to efiect a substantially slower movement of the die blocks through the remainder of their travel,

4. A shell banding machine comprising, in combination, a head movable between retracted and operated positions, means carried by the head for holding, a peripherally grooved shell, means for holding a driving band in alinement with the groove in the shell, die mechanism adapted when partially operatedto engage the driving band and when fully Operated to press the band into the groove in the shell, actuating means for said die mechanism operated in response to the movement of the head to operated position, power actuated means for moving the head, and control means for regulating said power actuated means to efiect an initial rapid movement of the head for parclosed on the band t0 D S- the m into the Q tially operating the die mechanism followed by a groove in the shell, actuating means for said die mechanism operable in response tothe movement of thejhead, pressure fluid actuated means for advancing and retracting the head, a two posisubstantially slower movement of the head to complete the operationof the die mechanism.

CARL C. GRO'I'NES.