US2378302A - Method and means for generating helices - Google Patents

Description

June 12, 1945.

J. E. KLINE METHOD AND MEANS FOR GENERATING HELICES Filed Aug; 22, 1942 3 Sheets-Sheet l INVENTOR 7' \T Z: {Zken A'ITO Y5.

June 12, 1945. Y J. E. KLINE 2,378,302

METHOD AND MEANS FbR GENERATING HELICES Filed Aug. 22, 1942 3 Sheets-Sheet 2 INVENTOR .721, z /Zz}7.

June 12, .1. E. KLlNE METHOD AND MEANS FOR GENERATING HELICES 5 Sheets-She et 3 Filed Aug. 22, 1942 INVENTOR ll! W3 m N m m Patented June 12, 1945 METHOD AND MEANS non GENERATING HELICES John E. Kline, Grosse Pointe Farms, Mich... as-

signor to Micromatic Hone Corporation, Dee troit, Micln, a corporation oi! Michigan Application August 22, 1942, Serial No. d55,'7ll2 10 Claims.

This invention relates to methods and devices for producing helices and particularly to a method and device for rotating an element in/predetermined relation to its pitch circle'and axial movement.

It has been the practice in the gun construction art to employ single or multiple tools or a series of broaches for cutting the'grooves in the wall t the barrel to produce lands of predetermined helical form projecting from the wall thereof. This proved not only to be a lengthy process requiring extreme care and skill, but often resulted inthe production of a large number of defectivebarrels. The tools would pile up cuttings as they advanced through the barrel which prevented the proper functioning. of the cutting teeth and the metal would be torn and a rough enlarged groove would be formed in the gun barrel. A lapping operation is then necessary to smooth the walls and base of the grooves between the lands'as an endeavor to salvage the workpiece.

' One phase of the present invention has for its object the use of a device for rotating a honing tool having one or a plurality of sets of honing ployed when performing the cutting or honing operations on cylindrical elements such as .broaches, lea-d bars, gun barrels and the like when utilizing the method and device embodying this invention. The device comprises a drum having a pair of cables wound thereabout in opposite directions and which are stationarily anchored at opposite ends of the machine. The cables extend over a pair of adjacent pulleys and are drawn taut to eliminate any backlash between the movements in rotation and reciprocation of the tool. As the tool is advanced, one section of the cable unwinds from one of the drum sheaves while the l and,

when: the helix is extremely long, a will be apother section is winding upon the other and the rotation produced to the drum and therefore the tool in this manner is timedwith the advancing movement of'the table carryingthe drum and tool. After the tool is advanced to cutting position, it is relatively reciprocated over the entire length or the workpiece as it is rotated by the winding and unwinding of the cables over the drum.

L In producing helical slots or grooves in the in faster than the tool or workpiece but the re-' .ternal or external surface of a workpiece, the relative rotation oi the tool and workpiece is timed with the relative longitudinal movement therebetween by the cables operating on the drum, the

pitch circumference of which i equal to the desired lead of the helices produced on the workpiece. The length of the helical lead of the workpiece and the size of the cable predicate the diameterof the drum over which the cable is wound for rotating the tool or workpiece about its axis. The diameter oi-the drum is obtained by dividing the required lead by pi and subtracting the. diameter of cable therefrom. The circumference of the axis of the cable on the drum will thus equal the lead of the'helix, which is the length of the workpiece in which the helix makes one complete turn. If the cable is to have more t 11 one wrap around the drum, as may be required the'generation of helices having more than one turn, it is obvious that the cables may require a comparable number of turns around the drum thus describing a slight spiral thereabout. In

such instances the root (or base) diameter of the drum is obtained by dividing the lead of the helix to be generated on the workpiece by pi times 3 equals root (or base) diameter of the required L equals lead of helix desired in workpiece a equals angle of spiral of cable about the drum Y (with respect to the transverse plane of the latter) d equals diameter of cable.

Then:

' B u is a d eq 3 pi sec-a parent that the circumference of the drum must be large and its diameter will reach sucha proportion that it willbe impractical to use the invention on a standard type of machine. For this reason, a reduction gear unit may be employed in combination with a reduced drum diameter to proreciprocation. The smaller drum may then rotate several times duce the timed rotation between the rotation and duction gear unit compensates for this taster I Then:

rotation. .The root (or base) diameter or the spiral grooves in this smaller drum is obtained by dividing the length of lead to be generated upon the workpiece by the product or the ratio oi gear reduction times "pif times the secant of the angle or the spiral oi the cable around the drum and subtracting the diameter of the cable from the quotient thereof; or:

.R equals number'oi teeth in internal gear divided by number of teeth in Sun gear of reducer B equals minus d I It is also within the purview of this invention to employ a drum having a pair or like sheaves which are 'of spiral-helical form so as to produce an accelerated lead to the helical groove generated, as is the case in some gun barre1s. By changing the spiral-helical form of the sheaves,

' the rotation of the tool or workpiece may be prorelative axial movement'between the work and 1 the tool to create a precise oscillatory movement may be reciprocated. The table supports a drivtherebetween; to mount a drum on a reciprocable head for rotating va tool or workpiece through a set of reduction gears thereby reducing the size of the drum to be actuated by a pair of cables wound thereover in opposite directions; to provide a fluid actuated cylinder on the head of the reciprocable carriage for expanding and contracting the stones of the honing tool; to form a drum having two sheave portions which are of spiral-helical form for varying the lead angle of the slots generated .by the tool, and, in general,

to provide an adapting means to a commercial machine for rotating a tool or workpiece in pre-' determined relation to its reciprocation while eliminating backlash between them during alternate direction of reciprocation therebetween. v

Other objects and features of novelty of this invention will be specifically pointed out or will become apparent when referring, for a better un-'- derstanding oithe invention, to the following de-- scription taken in conjunction with the'accompanying drawings, wherein: I

Figure l is a plan view or a honing machine which embodies features-of the invention:

' Fig. 2 is an enlarged sectional view 01'- a portion of the drlving'end oi the tool provided on the machine illustrated in Fig. 1: a

Fig. 3 is a sectional view of a drum and drivin: portion 01' a device similar to that illustrated in Fig. 1 showing arurtl'ier form which invention may assume:

ing head l3 having a recess in which a shank 14 on one end of a drum I5 is inserted for rigidly supporting the drum. The drum 15 rotates lZion the shank l4 and is provided with a pair of sets of helical grooves ii and I! of the same d. The grooves form a pair of sheaves upon which a pair of cables l8 and I9 are secured and are wound in opposite directions. The'head l3 has a bracket 2| secured thereto on which a pluralityof pulleys 22 and 23 are pivotally supported on pins 24. The'cables l3 and I9 extend over the pulleys 22 and 23, respectively, and their ends are secured to adjustable I-bolts 25 and 26 at opposite ends of the bed I I. Nuts 21 on the end of the I-bolts take up the slack in the cables I9 and I3 and retain them taut over the pulley and about the sheave portions of the drum l5.

The drum is provided with a tool-receiving collet 28 in which the driving end 29 of the tool 3! is secured. The driving end 29 01 the tool is hollow and an adjusting rodJZ extends therethrough, as illustrated more clearly in Fig. 2. The

the head'l3 as illustrated in- Fig. 1. Fluid is conducted to the cylinder and is employed for moving the piston to the leit or right for contracting and expanding, respectively, the abrasive stones 36 carried by the tool 3|.

' The rod extends through the universal joint 31 on the driving and 29 of the tool which is secured by pinsto the end of a driving tube 39. A pin'4l extends through the rod 92, through a slot 42 in the tube 39, and into an outer sleeve.

43 which extends thereover. An internally threaded collar 44 isiromtably secured to the end or the sleeve 4: by a plurality of balls 45 which are retained in position by a collar '46 which is secured to the sleeve by pins 41. The threads 43 of the sleeve 44 engage tht threads 49 on a sleeve 5i disposed over the tube 39. A pin 52 extends through a slot 53 in the tube 39 and through a block 54 disposed within the tube.

An adjusting rod BI is threaded into 'the end of the block 94 and extends the entire length oi the tube 39- to the body of the tool containing. .the stones 36. A spring-pressed ball 56 secures the pin 52 against axial movement while a springpressed ball 51' is employedn for retaining the I sleeve 44 in adjusted positio By rotating the sleeve '44, the sleeve II is extended or retracted so as to extend or retract the adjusting rod 5|. When fluid is admitted to the cylinder 35 on the right hand side of the piston 34, the piston 341s 4| to the sleeves 44 and Bland then through Fig.4 is a view of a drum similar-to thatillus- .trated in Fig. 1 showing a further form or the invention; and x Fig. 5 is a plan viewoi' structure similar to that illustrated in 1 showing a further form or theinvention. I v

Referring to m. l, a honing machine |l.isi1- lustrated having a bed II on which stable 12 the ins: to the adjusting rod is.

'rhetube 39 is connected by'a universal connection 3| to tool body whichhas a series of aper-' turea therein which are helicall disposed with reference to the bodyaxis. Stone holders carrying the stones 36 are disposed within the'slots for radial movement. Within the body, tapered members are provided ior engasinz the stone holders and moving them outwardly when the rod 33 is advanced to he lei'tasviewedin the 118m. When the rod is m ved in the'opposite direction, the pressure on thelstones is released-and these may retract or be retracted by suitable spring means. The tool follows the construction or that illustrated and described the copending application of J. E. Kline and .C. S. White'Serial No. 456,608, filed August 29, 1942 which was assigned to the assignee of the present invention.

A cradle 63 is employed adjacent to the end of the gun barrel 64 for receiving the end of the honing tool when the tool is withdrawn from the barrel. The extending frame 65 of the base 4 II has a plurality of supporting brackets 68 upon which the barrel is clamped in substantially .aligned relation with the tool 3I. The universal ports an arbor II on which a spider I2 is secured by keys 13. The spider carries a plurality of gears I4, preferably four or more in number, to form an even number of gears for a purpose which willbe explained more fully hereinafter.

A housing 15 carries an internal gear IS, the teeth of which are in mesh with the teeth of the pinion gears 14. A sleeve 11 contains an extemal'gear I8, the teeth of which are also in meshv with the pinions 14. The sleeve has a drum 19 secured thereto by keys 8| and has onits outer'face the sheave portions 82 and 83, the leads of the grooves of which are both right or both left hand depending upon the hand of helix to be generated. The sleeve H hasan internally projecting pin 94 which extends into a helical gr e 85, the lead of which is the same as the lead of the grooves in the sheaves so that the drum will advance along the arbor II to maintain the cable grooves in tangential alignment with the pulleys in H9 and I2I in all positions of the drum.

A- set of radial thrust bearings 86 supports the sun gear 18 to the internal gear 16 and the number of turns to be made within the length of the barrel. If a three to one relation exists between the rotation of the drum I9 and housing I5, then the nominal diameter of the drum 19 may be one-third that of the diameter of a drum which would be employed if a direct drive were utilized between the drum and the adapter 94. In this manner, the large cumbersome drum, which would otherwise be required, is eliminated.

Backlash will be entirely eliminated from between the cables and drum, by suitably tensioning the former, and also from between the gears by utilizing the sets of gears which may be offset in opposite directions to eliminate any play between' the teeth. When the drum is rotated as a result of the advance of table I2, the gear I8 is caused to rotate! and drive the pinions 14 on stationary axes and they in turn drive the ring gear 16 which rotates the housing I5 at a speed in predetermined ratio and in the opposite direction to thatof-the gear I8. This rotates the tool supporting adapter 94 and-the tool in predetermined timed relation to the advancement of the table I2 and the tool 3|.

Referring to Fig. 4,. a drum 96 is illustrated having two sheave portions 91 and 98 which are of spiral helical form and which may be substituted for-the drums I5 or 19 above referred to. One or aplurality of cables I00 are wound around each of thesheaves havingone end of said cables secured thereto at the major diameter of one sheave and at the minordiameter of the other sheave and the other ends of the cables extending to 'the rear at the points 99 and IIII.

' A drum of this particular type will progressively changethe speed of rotation of the tool relative to its movement in reciprocation so that an accelerating or increasing lead may be provided to the grooves in the barrel of the gun, which is desirable in certain types of gun barrel construchousing 15 on the arbor ll while the extending portion '81 of the housing has bearing relation with the sleeve 11. An adjusting rod 88 extends through the arbor II, with one end abutting against the piston rod 33 in the head I3, the other end of which abuts against the adjusting rod 32 of the tool.

The pinions 14 are mounted on shafts 89, the

' ends 9| and 92 of which are mounted eccentric to the central body portion so that the axes of alternate pinions 14 may be annularly offset in end 29 of the tool may be secured in the head 94 in-the same manner as the driving end was secured to the head 28 of the drum illustrated in Figs. land 2. When a barrel is to have slots honed therein which are of considerable length of lead, one that would require a drum of large diameter if the structure of Fig. 1 were emany number of revolutions during one revolution of the-tool, depending upon the relation of the tion. It is within the purview of this invention to vary the lead of the spiral angle of the sheaves so that the increase of the lead of the slot in the barrel will be'variable rather than constant from the breech to the muzzle of the gun. The

lands between such slots will produce very little turning of the shell near the breach andwill increase to maximum turning at the muzzle. By having both of the sheave portions 91 and 98 exactly alike, whether they are of constant or variable spiral angle, the cables are'maintained taut at all times so that no backlash will be present in the tool as it is reciprocated through the barrel.

In Figure 5, amachine IOI is illustrated in which the rotating device is applied to the workpiece, on the surface of which helical grooves are to be machined. The machine embodies a base I02 having ways, I03 on which a carriage I I04 is reciprocated. The carriage is operated by a lead screw (not shown) attached to a hand ployed, the structure illustrated in Fig. 3 is utilized instead. The smaller drum 19 may make wheel I05, which is driven through gears (not shown) in the conventional manner. The carriage I04 has a head stock I06 to which a drum I 01 is secured by a stub shaft I08. The drum freely rotates on the shaft and carries an index plate I09, to which a workpiece III is secured to rotate as aunit with the drum. The opposite end of. the workpiece is supported by a center H2 in a tail stock II3 having a hand wheel H4 which moves the centeri I2 axially.

The bed of themachine also supports-a head II5 which drives a milling cutter IIS in rotation or carries a suitable stationary cutting tool. such plained hereinabove.

by the lead screw on the'ways I03. This advances, the workpiece IJI past the cutter H6, and during such advancement the drum I20, index plate I", and workpiece I l l are rotated in timed relation thereto independent of the lead screw which drives the carriage.

The drum I2! is provided with a pair of cables Ill and H8, whichextend'over pulleys Ill and I2! journalled on the carriage, and have their ends secured byeye-bolts i22 tothe bosses I23 which are secured to the base I02. The nuts I24 on the eye-bolts draw the cables II] and I I8 taut over the pulleys and about the drums, as ex- As the carriage I04 advances to the left, as illustrated in the figure, the cable 5 winds of! of the drum while the table II! winds thereon.

This rotates the workpiece Ill clockwise, as

viewed from the right hand end of the, machine,

Upon the reverse movement of the machine.-

after the advancement of the cutting tool H6 toward the workpiece axis, the slot is deepened On the reverse movement of the carriage I04.

2, The combination with an element in the nature of a tool, a drum for rotating said element, said drum having a pair of like sheaves of spiral helical form, a gear unit disposed between said drum and element, and cables over said sheaves wound thereon in opposite directions.-

3. In a honin'g machine, a reciprocable carriage, a head on said carriage, a drum on said directions for rotating said drum as the carriage is moved, a cylinder on said head, a piston in said cylinder having a rod projecting into said head, and an adjusting rod in said tool operable by said piston rod. i

4. In a honing machine, a reciprocable carriage, a head on said carriage, a drum carried by said head for rotation relative thereto, a gear unit operated by said drum, a honing tool connected to said gear unit for rotation at a speed difierent from that of the drum, and cables without adding width thereto while the tool accuratelyfollows the helical lead. In m'anner, depth may be added to the'slot in each direction of movement of the carriage. After the slot has been machined to depth, the plate "9' may be rotated to index the workpiece If! in. position to machine the next adjacent slot in the surface thereof. 1

n. is to be understood that the gear reduction v element of Figure 3 and the spiral helical sheaves on the drum of-Figure 4 may be employed on the first rod. x

- 6. In a machine, a reciprocable carriage, a head machine llll, either alone or in combination, for

the Purpose hereinabove more fully explained. It will thus be seen that the invention is useful not only in rotating tools in a predetermined manner relative tothe workpiece, but also the workpiece in relation to the tool. This rotation may be applied to either the tool or the work-- piece when machining the internal or external surfaces of the latter. Either-the tool or the" workpiece will be rotated in synchronism with its reciprocation to generate a predetermined helical lead to a groove machined in the surface of the workpiece...

. While reference was made hereinto honing when employing abrading sticks, it is'to be under-' stood that the invention is not limited to machine ing by an'abrasive material. Diamond impreghated cutting elements could be employed in place of the abrasive-sticks, as well as file-like elements which could be substituted therefor. While heretofore the machining of the groov in a cylinder wall could be accomplished only n the advancing movement of the toolythe abrasive sticks,

tool and workpiece in both directions of reciprocation thereof.

What is claimed is: a

1. The/ combination with element in the nature of atool, a drum for rotating said. element as. it is moved axially, said rumihaving a pair oflike sheaves of spiral helical form for. producing a varying speed of rotation of the elementrelative to its longitudinal movement.

, wound in opposite directions over said drum f or producing the drums rotation when the carriage is moved.

said head for rotation relative thereto, a gear, unit operated by said drum, a honing to'olvconnected to said gearunit for rotation at a speed diflerent from that of the drum, cables wound in opposite directions-over said drum-for producing the drum's rotation when the carriage is moved, a piston and cylinder carried by said head, a rod iff said head actuated by said piston, and an adjusting rod in said tool operated by said carried'thereby, a drum mounted on said head having a pair of sheaves of spiral helical form,

a tool carried by said drum, a pair of cables wound on said sheaves for producing the rotation of said tool ata varying rate as it is advanced by said carriage.

7. In a honing machine, a reciprocable carriage, a head carried thereby; a drum mounted.

on said head having a pair of sheaves of spiral helical form, a honing tool carried by said drum,

a pair of cables wound on said sheaves for producing the rotation of said tool a varying amount as it is advanced by said carriage, a piston and cylinder on said head, a rod in siiid head operated by said piston, and an adjusting rod within said honing tool operated by said first rod for adjusting the diameter of the honing tool.

8. In a honing machine, a reciprocable carriage having a tool carrying head, a drum supported by said head having a pair of sheaves of spiral helical form, a gear unit driven by said drum, a tool supported and driven by said gear unit, and

a pair of cables wound in opposite directions riage having a tool carrying head) a drum sup-' ported by said head having a pair of sheaves of spiral helical form, .a gear unit driven by said.

drum, a to supported and driven'by said gear unit, a pair of cablesv wound about said sheaves for rotating said tool a varying amount and at a different speed from that of the drum, .as the tool is advanced by the carriage. a piston and cyl- 37 index carried by said head, a rod in. said head a a plurality of cutting elements within the barrel.

rotating said tool in timed relation to said reciprocation, radially moving the cutting elements or said tool while the tool is being reciprocated and rotated, and machining the slots in said barrel on both strokes in reciprocation of said tool.

JOHN E. KLINE.

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