US3863529A

US3863529A - Method for trimming cartridge cases

Info

Publication number: US3863529A
Application number: US348488A
Authority: US
Inventors: Robert J Bolen
Original assignee: Remington Arms Co LLC
Current assignee: Remington Arms Co LLC
Priority date: 1973-04-06
Filing date: 1973-04-06
Publication date: 1975-02-04
Anticipated expiration: 1992-02-04

Abstract

A mandrel is lowered into an open end portion of a tubular metal casing. A cutting tool is moved inwardly toward the end of the mandrel at a preset rate while revolving around the mandrel at a predetermined speed. The cutting tool severs a ringlet from the open end portion of the casing and holds the severed ringlet on the mandrel until after the mandrel has been removed from the trimming site, whereupon the cutting tool is separated from the mandrel and releases the scrap ringlet for orderly disposal.

Description

United States Eatent n 1 Bolen Feb. 4, 1975 METHOD FOR TRIMMING CARTRIDGE- CASES Inventor: Robert J. Bolen, Port Penn, Del.

Remington Arms Company, Inc., Bridgeport, Conn.

Filed: Apr. 6, 1973 Appl. No: 348,488

Assignee:

US. Cl 82/47, 29/132, 82/702 Int. Cl B2311 l/00, B23 3/22, 821d 51/54 Field of Search 29/132, 1.3; 82/47, 71-77,

References Cited UNITED STATES PATENTS 2/1946 Smiley 82/76 6/1964 Manshel ..82/70.2

Primary Examiner-Andrew R. Juhasz Assistant Examiner-Leon Gilden Attorney, Agent, or Firm-John H. Lewis, .lr.; Nicholas Skovran [57] ABSTRACT A mandrel is lowered into an open end portion of a tubular metal casing. A cutting tool is moved inwardly toward the end of the mandrel at a preset rate while revolving around the mandrel at a predetermined speed. The cutting tool severs a ringlet from the open end portion of the casing and holds the severed ringlet on the mandrel until after the mandrel has been re moved from the trimming site, whereupon the cutting tool is separated from the mandrel and releases the scrap ringlet for orderly disposal.

4 Claims, 6 Drawing Figures will PATENIEB FEB M975 SHEET 20F 5 METHOD FOR TRIMMING CARTRIDGE CASES This invention relates to a machine for cutting-off or trimming metallic tubes or tubular articles and more particularly to a trimming device which includes means for holding the trimmed portions of the tubes for controlled disposal.

For the sake of clarity and conciseness, it is proposed to confine the description of the invention to its application to machines for cutting-off the open ends of metallic tubular articles adapted to the manufacture of cartridge cases, but it will be understood that this par ticular adaptation is for the purpose of illustration only and that the invention may have other similar and equivalent uses within the scope of the appended claims.

Cartridge cases are generally manufactured from a metal blank. The blank is formed into a cup which is annealed and then drawn to a desired length and wall thickness; This generally cylindrical drawn cup, hereinafter referred to as a casing, normally has one open end which, due to the manner in which the casing is formed, tends to have a rough and uneven edge. To provide a smooth, even edge and ensure that the cartridge cases formed from the casings are of uniform length, a trimming step is utilized to sever the rough, open end portions from the casings.

Lathe-type devices have been utilized in the prior art to perform this trimmingstep. A typical machine is dis- I closed in US. Pat. No. 2,321,298, issued to Charles R. Johnson on June 8, 1943. The cartridge case is fed into a chuck which rotates the cartridge case at high speed while a trimming means seversa scrap ringlet from its open end. The cartridge case is then ejected from the chuck and a new one inserted. This procedure, requiring insertion and removal of objects in a spinning chuck, is highly time consuming and thus only adaptable to the trimming of center fire cartridge cases.

In the high speed operations required for the production of large numbers of rim fire cartridge cases, it is necessary that the casings be trimmed both rapidly and accurately. To accomplish this, the casings are gener' ally aligned with their open ends extending in one direction and are transported to a cutting site where a knife blade or, more often, a trim saw slices off the uneven end portion.

Due to cost and other factors, there has been an increased tendency to manufacture cartridge cases from materials other than brass. One very popular material has been steel. It has been found that, while casings made of easily machined metals, such as brass, can be easily trimmed by a trim saw, the use of such a device for casings made of less machinable metals, such as carbon steel, results in difficult and inefficient operation.

A trim saw is generally in the form of a high speed circular saw which is mounted in a fixed position while rigidly held casings are transported through the trimming site. The saw is positioned so that it will cut each casing to the same desired length, the plane of the out being generally perpendicular to the longitudinal axis of the casing. However, the motion of the casings and the high rotational speed of the cutting blade cause the ringlets of metal severed from the open ends of the casings to be randomly propelled at high speed making collection of more than a small portion of the trimming scrap extremely difficult, if not impossible. The scrap thus tends to collect in and around neighboring machinery and, regardless of attempts at prevention, the

trimmed metal ringlets, or portions thereof, find their way into moving parts and between bearing surfaces.

This relatively uncontrolled disposal of trim scrap has long been viewed as an undesirable but tolerable problem in the manufacture of brass cartridge cases. Proper collection and disposal of scrap would be desirable but, due to the low hardness and high lubricity of brass, the scrap causes little damage to bearings or other moving parts.

However, in the manufacture of'steel cartridge cases. the manner of disposal of scrap is of great significance. Steel has a much greater hardness than does brass and lacks its lubricity. Pieces of steel scrap working their way into a bearing would soon severely damage or destroy it. Moving parts could be jammed or damaged by a buildup of steel scrap.

In accordance with this invention, a novel method and machine are provided for trimming the open end portions from metal casings whereby the trimmed portion is held by the cutter blade after it has been severed from the casing. The trimmed portion is removed from the trimming site and then released so that an orderly disposal of the trimmed portion may be effected.

It is an object of this invention to provide a metal casing trimming means which may be used with either hard or soft metals.

It is another object of this invention to provide a metal casing trimming means which permits orderly disposal of scrap.

It is a further object of this invention to provide a metal casing trimming means having a cutter means which both severs the open end portion from the casing and holds the severed end portion for orderly disposal.

It is an additional object of this invention to provide a method of trimming metal casings whereby severed end portions of the casings are held after severing, removed from the trimming site, and released for orderly disposal.

These and other objects and advantages ofthis invention can be best described with reference to the accompanying drawings, in which:

FIG. 1 is a front view of a cartridge case trimming machine in accordance with this invention;

FIG. 2 is a side view of the trimming machine of FIG. I in a cutting configuration;

FIG. 3 is a fragmentary perspective view, partially cut away, of the trimming machine of FIG. ll;

FIG. 4 is an exploded perspective view of a trim head assembly of the trimming machine of FIG. 1;

FIG. 5 is a side view of the trim head assembly in a raised position with a cutting tool thereof in a closed configuration; and

FIG. 6 is a side view similar to FIG. 5 with the cutting tool in an open configuration.

The tubular casing trimming method of this invention generally comprises the steps of positioning the casing in axial alignment with a mandrel, an open end portion of the casing being directed toward the mandrel, positioning the mandrel within the open end portion, severing a ringlet from the open end portion of the casing, holding the ringlet on the mandrel, separating the mandrel from the trimmed casing and releasing the ringlet.

Referring now to FIGS. 1-4, a cartridge case trimming machine 11 is illustrated which may have a fixed frame I2 having a pair of upstanding sidewalls M. A metallic base I5 is supported between the sidewalls 14 with a pair of oppositely positioned gibs 16 (FIG. 2) positioned in corresponding vertical grooves or ways 17 which are formed on the sidewalls 14. An operating shaft 19 is rotatably held by the sidewalls 14 in a substantially horizontal orientation and may have a large operating wheel 20 secured at one end portion to facilitate rotation of the shaft 19 by connection through a belt (not shown) to an operating motor in a well known manner. The shaft 19 is provided with an axially dis placed eccentric portion 19a which is operatively connected through a link 21 to the base 15. During rotation of the shaft 19, the eccentric portion 19a reciprocates between positions vertically displaced alternately above and below the axis ofthe shaft 19 so that the link 21 is vertically reciprocated therewith. The base 15, being connected to the link 21, is reciprocated along with the link 21. This vertical motion is permitted by interaction of the gibs 16 in the vertical ways 17, which also maintains the proper orientation of the base. In this manner, vertical support is provided for the base 15 which is also thus vertically reciprocated one full cycle upon each rotation of the operating shaft 19.

A forward portion 15a of the base 15 has a vertical opening 22 (FIG. 3) provided therein. A pair of bearings 24 rotatably support a trim head assembly 25 within the opening 22.

The trim head assembly 25, best shown in FIGS. 3 and 4, has an outer shaft 26 which engages the bearings 24 between an external flange 26a and a nut 27 which is tightly fitted onto a threaded portion 26b of the outer shaft 26. An upper end portion 260 of the outer shaft 26 has a pulley 29 affixed thereto to provide rotation of the outer shaft through connection by a belt 30 to a motor 31 (see FIG. 2) which may be attached to the frame 12. A lower end portion of the outer shaft 26 has a pair of downwardly extending legs 26d formed integrally therewith.

An inner shaft 32 has an elongated cylindrical portion 32a which extends through an axial opening 34 in the outer shaft 26. An enlarged lower portion 32b of the inner shaft 32 has a pair of downwardly extending legs 320 formed integrally therewith. An upper end portion 32d (FIG. 2) is journaled in a bearing 35 of a lever assembly 36. A washer 37 fitted in a slot (not shown) in the upper end portion 32d of the inner shaft 32 supports one end portion of a biasing spring 39 which also acts on the upper end portion 26c of the outer shaft 26 to urge the inner shaft 32 upwardly therefrom.

A mandrel 40 (FIG. 4) is held in an axial bore provided in the inner shaft 32 and extends downwardly therefrom. The mandrel 40 may be held in place by a set screw 41. To accommodate the set screw, a flattened portion 40a may be provided at a desired loca tion on the mandrel.

A conventional cutting tool 42 is preferably mounted in a tool block 44 in any convenient manner, such as through the use of a set screw 45. The tool block 44 may be attached to a tool holder 46 by a threaded fastener (not shown). A counterbalancing member 47 is provided to prevent damage which might otherwise be caused by the eccentricity of the mass of the tool block 44 and tool holder 46. The counterbalancing member 47 preferably has the same weight and general configuration as the assembled tool holder 46 and tool block 44. Interlocking

ears

46a and 47a on the tool holder 46 and counterbalancing member 47, respectively, are positioned so that their

respective openings

49 and 50 can be aligned with each other to permit a pin 51 to be passed through the openings 49 and and through openings 26e in the legs 26d of the outer shaft 26 to pivotably attach the tool holder 46 and counterbalancing member 47 to the outer shaft 26. A vertical bore 51a through the pin 51 is preferably provided to allow the mandrel 40 to pass through the pin 51 without interference.

The tool holder 46 and counterbalancing member 47 each have an additional pair of ears 46b and 47b, respectively, which are attached to links 52 by passing pins 54 through openings in each pair of ears and an aligned one of a pair of apertures 55, provided in each of the links 52. The links 52 are, in turn, connected to the inner shaft 32 by pins 56 passed through other of the pair of the link apertures and through aligned openings 32e in the legs 320. An inner end portion of each link 52 may be provided with a groove 52a to prevent interference with the mandrel 40.

The lever assembly 36 (FIGS. 1-3) controls the motion of the inner shaft 32 relative to the outer shaft 26 and has a vertical member 57 which is attached to the forward portion 15a of the base 15 by threaded fasteners 59 or other suitable attachment means. An upper end portion of the member 57 serves as a fulcrum 57a for the lever assembly 36 and may be bifurcated for better securement of the lever assembly.

A pair of

levers

60 and 61 and preferably pivotably attached to the fulcrum 57a by suitable fasteners such as pins 62. The

levers

60 and 61 are pivotably attached to an extended upper portion 35a of the bearing 35 by pins 64. Suitable openings are preferably provided in the

levers

60 and 61 to accommodate the passage of the extended upper portion 35a of the bearing 35 therethrough.

A rear portion 610 of the lever 61 is pivotably attached to a suitable cam follower 65 which rides on a cam 66 which is mounted on the operating shaft 19 for rotation therewith. The rear portion 61a of the lever 61 may be laterally displaced to permit proper alignment of the cam follower 65 with the cam 66. The cam follower 65 preferably has a plurality of fingers 65a which interact with the operating shaft 19 to maintain the proper alignment of the cam follower 65 and a roller 65b which interacts with a camming surface 66a of the cam 66 to produce the desired motion of the lever 61. During rotation of the operating shaft 19, interaction of the cam follower 65 with the cam 66, through the lever 61, varies the position of the inner shaft 32 relative to the outer shaft 26 to control the position of the cutting tool 42 in a manner hereinafter described in detail. Thus, a proper contour of the camming surface 660 can produce any desired motion of the cutting tool 42 during each cycle of reciprocation of the base 15.

Casings 67 to be trimmed by the cartridge case trimming machine 11 may be carried to the trimming site by a rotating table 69 mounted to the frame 12 or by other suitable carriage means well known to those skilled in the art. Means for properly feeding the casings 67 into position on the rotating table 69 and for removing the trimmed casings 67a therefrom are also well known to those skilled in the art and are not shown.

Operation of the cartridge case trimming machine 11 will now be described with reference to FIGS. 1-6. The casing 67 to be trimmed is transported to the trimming site, i.e., to a position beneath and axially aligned with bly 25 is in a position elevated from the table 69 by virtue of the axis of the eccentric portion 19a being above the principal axis of the operating shaft 19; the orientation of the cam 66 permits the inner shaft 32 to be urged by the biasing spring 39 to its uppermost position with respect to the outer shaft 26.

As the casing 67 is being positioned at the trimming site, the trim head assembly is moved toward its necessary position to perform the trimming operation. It will be readily understood that the operations of the car tridge case trimming machine 11 and the rotating table 69 may be coordinated through the use of a timing belt or other means (not shown). Rotation of the operating shaft 19 lowers the base and thus the trim head assembly 25 toward the casing 67 to be trimmed. The action of the motor 31, through the belt 30, causes the pulley 29 and the outer shaft 26 to rotate at high speed. Because the outer shaft 26 isconnected to the inner shaft 32 through the tool holder 46 and counterbalancing member 47 and the links 52, both the inner shaft 32 and outer shaft 26 as well as the entire trim head assembly 25 are rotated by the motor 31.

While the base 15 is being lowered by the motion of the eccentric portion 19a of the operating shaft 19, the cam 66 is preferably urging the cam follower 65 downward so that the lever 61, pivoting around the fulcrum 57a, causes the inner shaft 32 to travel downwardly at a rate greater than the outer shaft 26 compressing the biasing spring 39. The relative downward motion of the inner shaft 32 with respect to the outer shaft 26 is conveyed through the links 52 to the tool holder 46 and counterbalancing member 47 causing them to rotate around the pin 51 in the directions of the respective arrows 70 in FIG. 5. At the same time, the downward motion of the inner shaft 32 lowers the mandrel 40 so that its extended end portion positions itself within the open end of the casing 67. This helps ensure the proper alignment of the casing 67 during trimming. The pivotal motion of the tool holder 46 about the pin 51 causes the cutting tool 42, which, as previously indicated, is rapidly rotating around the casing 67, to be moved inwardly toward the casing so that, upon reaching the proper vertical position, it cuts through the casing 67 severing a ringlet 6712 from its open end portion (see FIG. 2). It will be readily apparent that by properly coordinating the speed of revolution of the cutting tool 42 around the casing 67 and the rate of inward motion of the cutting tool, the cutting rate of the cartridge case trimming machine may be optimized, i.e., set at the maximum cutting rate possible for the material. As can be seen in FIGS. 2 and 5, the cutting tool 42 is located at a position just beneath the extended end portion of the mandrel 40 so that, until the tool holder 46 is rotated away from the mandrel 40, the ringlet 67b severed from the casing 67 is held on the mandrel 40 by the cutting tool 42.

Through interaction of the cam 66 and cam follower 65, the relative positions of the inner shaft 32 and outer shaft 26 causing the ringlet 67b to be retained on the mandrel 40 are retained while the trim head assembly 25 is raised vertically to the position shown in FIG. 5. Meanwhile, the table 69 may rotate moving the next casing 67 to the trimming site. Upon further rotation of the operating shaft 19, the cam 66 begins to release the cam follower 65, thus permitting upward motion of the lever 61. The upward force necessary to provide this motion is produced by the previously compressed biasing spring 39 which upwardly moves the inner shaft 32 with respect to the outer shaft 26 and causes the cam follower to follow the contour of the camming surface 66a for controlling the relative positions of the inner and outer shafts.

As the inner shaft 32 is moved upwardly by the biasing spring 39, this motion is translated through the links 52 so that the tool holder 46 and counterbalancing member 47 are rotated around the pin 51 in directions opposite those indicated by the respective arrows of FIG. 5. By this motion, the trim head assembly 25 assumes the physical configuration shown in FIG. 6. With the cutting tool 42 withdrawn from its former position beneath the mandrel 40, the ringlet 67!) which had been trimmed from the casing 67 is no longer held on the mandrel and falls therefrom for disposal. This may be accomplished by the use of several techniques as, for example, by directing a stream of a fluid, such as air. which will direct the ringlet toward and into a suction apparatus of a type well known to those skilled in the art. Alternatively, the structure could be modified to permit the trim head assembly 25 to be horizontally displaced from the vicinity of the trimming site prior to the release of the ringlet 6717 so that the ringlet could be allowed to fall freely into a bin or other collection apparatus without interfering with moving parts.

In this manner, a trimming machine is disclosed which is adjustable for optimum cutting speed and can remove scrap ringlets from even steel cartridge cases and hold the ringlet for removal from the trimming site for orderly and controlled disposal.

I claim:

I. A method of trimming a tubular casing having an open end portion with a trimming machine including a mandrel with an extended end and a cutting tool mounted for rotation around the mandrel, said method comprising the steps of rotating the cutting tool at a uniform speed, positioning a casing at a trimming site in axial alignment with the mandrel, moving the mandrel and rotating cutting tool toward the casing to position the extended end of the mandrel within the open end portion of said casing, moving the rotating cutting tool toward the extended end of the mandrel at a predetermined rate to sever a ringlet from the casing and hold the ringlet on the mandrel, removing the mandrel and rotating cutting tool from the casing, and moving the cutting tool away from the extended end of the mandrel to release the ringlet for gravitational removal from the mandrel.

2. A method as in claim 1 wherein said casing is of a material having an optimum cutting rate, and said uniform speed of rotation of said cutting tool and said predetermined rate of motion of said cutting tool are set to cause the cutting tool to sever a ringlet from said casing at substantially the optimum cutting rate.

3. A method as in claim 1 wherein said mandrel is positioned over a stream of fluid before said ringlet is released.

4. A method of trimming a plurality of tubular casings with a trimming machine including a vertically aligned mandrel with an extended end and a cutting tool mounted for high speed rotation around the mandrel, said method comprising the steps of rotating the cutting tool at a uniform speed, vertically aligning a plurality of casings in horizontally spaced relation with casing, moving the cutting tool away from the extended end of the mandrel to release the ringlet for gravitational removal from the mandrel, transporting a second casing to replace the first casing at the trimming site while the mandrel and rotating cutting tool are removed therefrom, and lowering the mandrel and cutting tool to trim the second casing.

Claims

1. A method of trimming a tubular casing having an open end portion with a trimming machine including a mandrel with an extended end and a cutting tool mounted for rotation around the mandrel, said method comprising the steps of rotating the cutting tool at a uniform speed, positioning a casing at a trimming site in axial alignment with the mandrel, moving the mandrel and rotating cutting tool toward the casing to position the extended end of the mandrel within the open end portion of said casing, moving the rotating cutting tool toward the extended end of the mandrel at a predetermined rate to sever a ringlet from the casing and hold the ringlet on the mandrel, removing the mandrel and rotating cutting tool from the casing, and moving the cutting tool away from the extended end of the mandrel to release the ringlet for gravitational removal from the mandrel.

4. A method of trimming a plurality of tubular casings with a trimming machine including a vertically aligned mandrel with an extended end and a cutting tool mounted for high speed rotation around the mandrel, said method comprising the steps of rotating the cutting tool at a uniform speed, vertically aligning a plurality of casings in horizontally spaced relation with an open end portion upwardly directed, transporting a first casing to a trimming site beneath the mandrel, lowering the mandrel and rotating cutting tool to position the extended end of the mandrel into the open end portion of the casing, moving the rotating cutting tool toward the extended end of the mandrel to sever a ringlet from the casing and hold the ringlet on the mandrel, lifting the mandrel and rotating cutting tool from the casing, moving the cutting tool away from the extended end of the mandrel to release the ringlet for gravitational removal from the mandrel, transporting a second casing to replace the first casing at the trimming site while the mandrel and rotating cutting tool are removed therefrom, and lowering the mandrel and cutting tool to trim the second casing.