US1759857A - Reproducing mechanism - Google Patents

Description

aEPRoDucim uzcrmusu Filed March 14, 192s: 4 Sheets-Sheet 2 C. KREBS REPBODUCING MECHANISM May 27, 1930.

4 Sheets-Sheet .3

Filed March 14, 1929 c. KREBs v REPRODUC ING HECHANI SM May 27, 1930.

Filed Match 14, 1929 4 Sheets-Shget 4 Patented May 27, 1930 UNITED STATES CARLOS KREBS BOSTON, MASSAGH'U'SETTS REPRODUGING MECHANISM Application filed March 14, 1929, Serial No This invention relates to an improvement in reproducing mechanism of the type shown in my copending application Serial No. 288,023, filed June 25, 1928, and which may be employed in various machines, as for example in the torch cutting machine disclosed in that application, and which includes means for controlling the reproductive movements of one or more tools or other elements used in cutting, welding, profiling and other ma- 'chinery having drives which are either directly or indirectly controlled.

The use of cutting machines of this character has increased greatly within the past few years for the purpose of producing standard parts which must be replaced pe-' riodically, such as locomotive parts, or for producing in large quantity parts to be used for the construction of new machinery. The template with which the tracer coacts is supposed to serve as a long-lasting pattern by the use of which parts are reproduced correctly so long as the pattern is serviceable,

sential that the reproductions be always the same, and it is accordinglyv necessary that the I specificfeatures of the cutting machines must be such that the parts are reproduced correctly and permanently. Moreover, it is now .the practice in electrical companies to produce smaller motors and generators in mass I production, using steel elements instead of castings. One factory of this type now turns 5 out 800 motor frames per week, each motor being provided with four legs, and those legs must be so formed that they can be fitted to the frames without further machining, and hence it is necessary that the cutting :ma .chines reproduce permanently correct parts 347,065, and, in Germany January 25", 1929.

erator.

In order that a cuttingmachine be formed to operate in the accurate manner above mentioned, three essential features must be provided: First, the tracer and cutting torch must be mounted upon a suspension system and be freely movable thereover in any or all directions in a horizontal plane; second, the

tracer and torch must be so mounted upon the suspension system that they, at all times,

work in a vertical, plane; third, the mechanism by which the movement is transmitted from the tracer to the torch must compel the torch to follow exactly the path'prescribed by the tracer.

Obviously all these points are fundamen tally interdependent and if in any of these features the machine is not properly designed, accurate reproduction can not be relied upon. The suspension system for the tracer and the torch must be of a kind that can not possibly get out of the exact horizontal plane and must be ofsubstantial and rigid construction permanently unaffected by any moving weights or strains. If the suspension system does not remain in the horizontal plane at all times, it obviously follows that the tracer and torch mounted thereon can not always work in the vertical position, and if the tracer and torch are not so constructed as to work in a vertical'plane, then, even if the suspension system therefor were perfectly designed, the result of the o eration of the machine will be unreliable." 11 other words, both the support and the tracer and torches must be so designed. that they keep within their respective planes permanently without any possibility of being shift-- ed therefrom, either by reason of any faulty construction, or by reason of the changing of the weights and strains which' take during the operation of the machine.

In order thattlie relative movement be properly transmitted between the tracer and the'torch, the means for so doingmust be sensitive, engaging instantly and forcibly without the possibility of ever developing any lost motion. Obviously this transmisplace sion means can not be a part of the supporting mechanism because the continuous shifting of the strains would destroy its value. In other words,the transmission means must transmit movement and can not be used for any other purpose.-

Many designs of cutting machines have been developed, but it'has been found that they do, not comply with the three requirements above given. If the suspension system forthe mechanism is su ported at one end only, it necessarily must ollow that the continual shifting of the weights during the operation of the machine will have a'tendency to move the suspension system out of the exact horizontal plane which it occupied when the machine'was new. Another objec tion to these machines 'is the fact that in' vman part as a support for the tracer and torch. I 1

The machine which is here shown, for the purpose of illustration, embodies a torch cut. ting machine in which the movement of a plurality of torches is controlled by and each torch reproduces the movement of a tracer which is guided by. a suitably formed pattern or template has been developed for the purpose of complying with each of the three requirements. T us, the suspension system is supported at its-center and the tracer and torch mechanisms are so arranged relative to this center support that they at all times balance each other and no undue strain is applied tothe'support at any time during the operation of the machine. Furthermore, the tracer and torches are freely movable vertically and in exact parallelism, and

finally, the transmission means functions" solely for that purpose and'has no load supporting function 'at any time. Therefore,

the torches will cut from the material upon which they work a plurality of articles which correspond in every particular to thepattern or template.

The primary object of; this invention is to provide a reproducing mechanism so constructed that a plurality. of articles may be simultaneously made by the operation of tools actuated by a single pattern or template controlled element.

Another object of this invention is to provide a repr'oducin mechanism embodying a tracer wheel guide by a template upon which it rests, and' means carried by the tracer wheel support for engaging the template to insure the movementof the wheel'at all times in conformance with the contour thereof.

A further object ofthis invention is to provide in a reproducingmechanism transmission meanswhich operate in'a horizontal plane to transmit motion from the tracer mechanism to the torch mechanism.

Other objectsjof this invention reside in the details of construction hereinafter set forth as willbe apparent to one skilledin the cases the transmission ,means acts. who y or in art from a consideration of the following specification taken in connection with .the

drawings which form a part thereof, and in which: 7

Fig. 1 is an elevation of a reproducing mechanism embodying this invention;

Fig. 2 is a plan view thereof illustrating primarily the suspension and transmission means; 0

Fig. 3 is a sectional view on a larger scale ofthe tracer; V 3

Fig. 4 is a side elevation on a similar scale of the lower portion of the tracer; and

Figs. 5 and 6 are sectional detail views illustrating portions of the transmission means.

-The embodiment set forth the drawings and described-in detail in the specification was selected as illustrative and not as limitative, is being understood that other. embodl:

ments can be made in which the. subject matter of rated.

Y Referring particularly to Figs. 1 and 2 of the drawings, it will be noted that the reprothis invention maybe incorpoducing mechanism includes a susupension' system here shown ascomprising a pair of platforms 10, each'of which is provided with a centrally located pedestal 11 by which the platform' is rotatably supported in a horizontal plane. Suitably formed pairs of carriages 12 and 13 respectively support the tracer and torch mechanism, the movement bar 17 carried by posts 18 in the carriages.

Thus each pair of carriages moves as a unit.

Each pedestal 11 comprises a fixedcentral column 20 mounted on a base 21 and provided with a capital 22 upon which the platform 7 10 rests. The base 21 may support both pedestals and be mounted upon parallel tracks 23 suitably supported upon a standard'24, I

or there may be separate bases21 suitably joined to move as a unit over the tracks 23. In the base 21 are mounted one or more axles 25 provided with wheels 26 which engage the tracks 23. One pedestal 11 also may be provided with a motor 27, a suitably formed gear box 28, a shaft 29, and a worm and gear assembly 30, whereby one of the shafts 25 is rotated. The operation of the motor by this construction causes the base 21 and the pedestals 11 andall the parts carried thereby to reciprocate over the track 23. Each capital 22 secured to its platform is mountedupon the column by antifriction means (not shown) sothat it can rotate freely thereon about the vertical axis 31, thus permitting it, together with its plat- Each of the carriages. 12. and 13 comprises a frame 46 which is supported by a pluralityof rollers 47, which rollers rest upon and are guided by the tracks 45. T

e tracer mechanism includes a tracer 50 supported upon the cross beam 15 which 'is connected to the carriages 12 in such a manner that the latter are free to oscillate relative to the ends of the beam. This may be attained in any desired manner, as for example, securingthe posts by suitable ball and thrust bearingsto the ends of the beam, so that the beam can turn easily thereon when required during the operation of the machine.

In the center of the beam15, preferably midway between its ends, is an aperture 51 through which passes a sleeve 52 depending from a plate or disk 53 supported upon the beam l5 as by legs 54, and secured thereto.

inanysuitabl'e manner.

The tracer is particularly shown in Figs. 3 and 4 of the drawings on a large scale.

Supported upon the plate or disk 53 by antifriction bearings is a turntable 56 which carries-a motor 57 by means of uprights 58. Rotatably mounted 'in bosses 60 formed on the uprights 58 is a shaft 61 which is actuated through a worm and gear assembly 62 by the motor 57. Mounted to rotate upon the turntable 56 between the uprights 58 are gear wheels 63 which are driven from the shaft 61 by intermeshing bevel gears 64. The turntable 56 has a central opening 65 within which a floating guide 66 preferably in the form of a tube extends. Mounted at the lower end of the tube 66 is a block 67 provided at its lower end with arms 68 which support a wheel shaft 69. Mounted upon the shaft 69 between the arms 68 is a wheel 70 which is driven by the motor 57 through the gears 63. The gears 63 mesh with spur gears 71 mounted upon the upper ends of shafts 72 which extend through the tube 66 and block 67 terminating between the arms 68. The lower ends of the shafts 72 are provided with beveled gears 74 which mesh with gear teeth 75 formed on the wheel 70. The wheel 70 is thus positively driven from the motor 57 by gearing which engages both sides of the wheel,'thus equalizing the pressure thereon and preventing the application of any undue strain against one side thereof.

The template 36 comprises a metal strip 76 which is bent in any suitable form and riveted to-a supportingplate. The wheel.70 includes a central annular flange 77 which rests upon the upper face of the strip 7 6. In order to hold the wheel in this position upon the strip, there are provided rollers 80 which rest against the sides of the strip. These rollers are vertically supported in levers 81 pivoted upon rods 82 carried by the arms 68. One or both of the levers 81 may be provided with an extension 83 which engages bracket 84 carried by the block 67. The bracket 84 is provided with a plurality of holes 85 and the extension 83 is provided with a single hole so that a pin 86 passing throughone of the holes 85 in the bracket 84 and through the hole in the extension 83 holds the rollers 80 in any desired position. vThe preferred position is that'shown in Fig. 4 in which the rollers 80 are slightly in advance of the contacting portion ofthe wheel 7 0. It has been found when so arranged that the wheel 70 will follow the path defined by the strip 76 without difliculty. The conformation of the upper end of the floating tube 66 and of the opening 65 is such that while the tube and its parts are free to reciprocate relative to the turntable 56, any rotation of the ,tube around itsvertical axis 90 will cause the turntable 56 to rotate similarly.

The torch mechanism comprises a plural ity of torches supported at the desired points upon the cross bar 17. The bar 17 is carried by the posts 18 through suitable ball and thrust bearings and may be extended to the length desired beyond the platforms 10. Each torch 100 may comprise a tube 101 which extends through a collar 102 clamped by arms 103 uponthe bar 17. Suitable means (not shown) may be provided to raise or lower the torch 100 as required and the gas or other fuel by which the flame of the torch is produced passes through the tube 101 to the outlet at its lower end in the usual manner.

As is clearly shown in Fig. 2 of the drawings, each platform 10 supports a. tracer carriage 12 and a torch carriage 13 wl1ich carriages are connected by transmission means 105 so that any movement of the carriage/12 over the platform 10 causes a movement of the carriage 13 over the platform 10 to the same extent but in the reverse direction. The transmission means 105 is'similar in many respects to that shown in my copending below, and in the fact that the various elements operate in a horizontal plane rather than in a vertical plane.

The means 105 comprise a pair of rack bars 106 and a gear 107 with which the teeth on the bars mesh. The car 107 is mounted upon a vertical stub sha 108 carried by the platform over the pedestal 11 preferably in the vertical axis 31. Suitably mounted idler rolls 109 (see Fig. 6) hold the teeth of the bars 106 inmesh with the gear'l07. The outer ends of the bars 106 may be attached to the carriages 12 and 13 by the means shown in Fig. 5. Mounted upon the frame 46 of the carriage is a Z-shaped bracket 110 Whlch is adjustably secured to the frame by set I screws 111 passed through slots 112. The

bracket 110 terminates in an outwardly proecting tongue 113 and projecting from the racket above and parallel to the tongue 113 is a second tongue 114. The end of the bar 106 enters the space between the tongues and is fixed therein by set screws 115 carried by the tongues. The tips of the screws enter depressions 116 in the upper and lower faces of the bar and thus permit the bar to oscillate slightly, should such movement be necessary at any time, without impairing in any respect the operation of the transmission means.

The construction of the reproducing mechanism thus described is such that the movement of the tracer wheel 70 over the strip 76 caused by the moto 5.7 is transmitted by f the cross beam 15 to the carriages 12, and

through the rack bars 106 and gears 107 to the carriages 13 and thence through the cross bar 17 to the torches 100. The torches are thus actuated by the tracer 50 and reproduces upon the work 41 replicas of the. template 36.

In the transmission system shown and described, the rack bars and ears are arranged in the horizontal plane, ut they could be arranged in vertical or other planes, if demechanism has been shown and described,.I

arn not limited thereto since other embodients can be made without departing fromthe spirit and scope of the invention as set forth in the following claims.

I claim:

1. A reproducing machine wherein the movement of the reproducing means is controlled by that of'a tracer relative to a template, comprising a single tracer; a pair of 4 tracer carriages, means connecting said car? riages and supporting said tracer, a plural- 1ty of reproducing tools, a pair of carriages supporting said tools and means joining each I 1. -d:.; -".gtracer carriage to a tool supporting carr age;

whereby the movement of the tracer relative";

to a template is transmitted to the'tools. M 2. A reproducing machine wherein the movement of the reproducing means is con: trolled by that of a tracer relative to a template, comprising a' single tracer, a pair of. tracer carriages, means connecting said carriages and supportingsaid tracer, a plurality of reproducing tools, a pair of carriages, means connecting said carriages and supporting said tools, and means joining each tracer carriage to a tool-supporting carriage whereby the movement of the tracer relative to a template is transmitted to the tools.

3. A reproducing machine wherein the e movement of the reproducing means is controlled by that of a tracer relative to a tem plate, comprising a single tracer, apair-of platforms, a pair of tracer carriages, each carriage being reciprocable over a platform, means connecting said carriages and supporting said tracer, a plurality of reproducing tools, a pair of carriages, each carriage being reciprocable over a platform, supporting said tools and means joining the tracer carriage and the tool-supporting carriage on each platform whereby the movement of the tracer g'elntive' to the template is transmitted to the 4. A reproducing machine wherein the movement of the reproducing means is controlled by that of a tracer relative to a tem-.

plate, comprising a single tracer, a pair of platforms, a pair of tracer carriages, each carriage bemg reciprocable over a platform, means connectlng said carrlages and supporting said tracer, a plurality of reproducing tools, a pair of carriages, each carriage being reciprocable over a platform, means connecting said carriages and supporting said tools,

and means joining the tracer carriage and the tool-supporting carriage on each platform whereby the movement of the tracer relative to the template is transmitted to the tools. 5. A reproducing machine comprising a single tracer and means causing said tracer to move relative to a template, tracer carriages by which said tracer is supported, a plurality of torches, torch carriages by which said torches are supported and means joining each torch carriage to a tracer carriage whereby the movement of the tracer is transmitted through the tracer and torch car riages to said torches.

' 6. A reproducing machine comprising a platform, ,a tracer carriage, a torchcarriage carriages, a tracer supported by said connecting means, means connecting said torch car riages, a torch supported by said second connecting means, a template and a tracer actuator causing said tracer to move relative to said template whereby said torch is caused to move in unison with the tracer. Y

7. In a reproducing machine comprising a. platform having a central pedestal, a pair of tracks and carriages reciprocable over said tracks, one carriage being at one side of the pedestal and the other'carriage being at the other side, means for transmitting motion from one carriage to the other and causing the carriages to move in opposite directions relative to the pedestal, consisting of a gear mounted to rotate in a horizontal plane over the pedestal and a pair of rack bars which mesh with the teeth of the gear, each bar being supported at one end by a carriage.

8. In a reproducing machine comprising-a platform having a central pedestal, a pair of tracks and carriages reciprocable over said tracks, one carriage being at one side of the pedestal and the other carriage being at the other side, means fortransmitting motion from one carriage to the other and causing the carriages to move in opposite directions relative to the pedestal, consisting of a gear mounted to rotate in a horizontal plane over the pedestal and a pair-of rack bars which mesh with the teeth of the gear-and vertically spaced tongues on each carriage between which tongues oneend of a rack bar is supported.

9. In a reproducing machine comprising a platform having a centralpedestal, a pair of tracks and carriages reciprocable over said tracks, one carriage being at one side of the pedestal and the other carriage being at the other side, means for transmitting motion from one'carriage to the other and causing the carriages to mov e in opposite directions relative to the pedestal, consisting of a gear mounted to rotate in a horizontal plane over the pedestal, and a pair of rack bars which mesh with the teeth of the gear, vertically spaced tongues on each carriage, .between which tongues one end of a rack bar enters, and set screws in said tongues which engage and support the rack bar while permitting a slight oscillation thereof. 10. In a reproducing'machine the combination with a strip template of a tracer comprising a wheel which bears upon the face a ofthe template strip and roller-grinding means which engage the sides of the strip to insure that the wheel follows the contour of the strip, such roller-grinding means consisting' of rollers mounted upon levers pivotally supported upon the tracer and engaging the sides of the strip in advance of the I line of contact of the wheel and the strip.

Signed by me at Boston, Massachusetts, this eleventh day of March, 1930.

,CARLOS KREBs.

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