US593556A - Machine - Google Patents

Description

7 Sheets-Sheet; 1'

(No Model.)

B. J. ABBOTT.

ENGRAVING MACHINE. v No. 593,556. Pa tented Nov. 16, 1897.

(No Model.) 7 SheetsSheet 2. 1 B. J. ABBOTT.

ENGRAVING MACHINE.

Patented Nov. 16,1897.

(No Model.)

7 Sheets-Sheet 3.

B. J. ABBOTT.

ENGRAVING MACHINE.

Patented Nov. 16, 1897. jg a no: uonms mans m., mammkx WASHINGTON, n. c.

' (No Model.) 7 sheets-sheet 5.

B. J. ABBOTT.

ENGRAVING MACHINE.

No. 593,556. Patented Nov. 16, 1897.

[No Model.) 7 Sheets-Sheet 6.

B. J. ABBOTT. ENGRAVING MACHINE.

No. 593,556 Patented Nov, 16, 1897.

(No Model.) 7 sheets sheat 7. B. J. ABBOTT.

ENGRAVING MACHINE.

No. 593,556. Patented Nov.'16, 1897.

mmlvs mans ca. monxuma. wummou, ac.

UNITED STATES PATENT OFFICE.

BENJAMIN JUDD ABBOTT, OF CHICAGO, ILLINOIS, ASSIGNOR TO CHARLES H. DURPHY, OF SAME PLACE.

ENG RAVING -MACHIN E.

SPECIFICATION forming part Of Letters Patent No. 593,556, dated November 16, 1897.

Application filed March 29, 1897. Serial No. 629,645. (No model.) I

T to whom it may concern: I The roller or cylinder upon the surface of Be itknown that LBENJAMIN J UDD ABBOTT, which are the dies to be sunk is represented at a citizen of the United States, residing in A, mounted on the projectingend of the shaft Chicago, in the county of Cook and State of B, which shaft may be termed the work- 55 Illinois, have invented a new and useful Imholder shaft. This work-holder shaft, by provement in Die-Sinking Machines, of which means of mechanism presently to be indithe following is a specification. cated, is oscillated through any required are The machine which constitutes the subjectby the operation of' the machine, the extent matter of this invention is one which is more of the oscillation being determined by adjust- 60 especially designed for doing the die-sinking ment, so that the shaft B will be swung work in machines employing dies in considthrough any determined arc, first in one dierable numbers of two kindsviz., rollerrection' and then in the other, to an extent dies, in which the matrices are formed upon according to the length of out required in the periphery of cylindrical rolls, and also sinking the die onthe face of the roller which 65 flat dies, in which the matrices are .formed isbeing operated upon,andsaidshaft orworkin fiat blocks, the roller-dies being used in holder B is so mounted in its bearings and such machines for rolling the shanks of articonnected to its driving mechanism that it cles and the flat dies for shaping the heads may also move 'endwise or be moved endwise or other parts. Although thus designed for to accommodate the lateral operation of the 7Q doing a special kind of work, the machine is milling-tool or cutter.

one adapted to perform any kind of die sink- The endwise movement of the shaft or ing, either upon a cylindrical or upon a plane work-holder B is accomplished as follows: surface, and also do almost every variety. of Mounted on the shaft B and oscillating theremilling-work. with is a finger or fingers B, and mounted 25 The nature of the invention will fully apon the non-revolving bearing 13 is a pattern pear from the following description and B the face of which where the finger B claims, taken in connection'with the accomcomes in contact with it is given a cam shape panying drawings, which form a part of this or configuration corresponding to the lateral specification, and in whichoutline of the matrix which is to be cut in the 30 Figure 1 is a front elevation of the imsurface of the oscillating work. A spring B proved machine. Fig. 2 is a side elevation; hearing at one end against the box B and at Fig. 3, a vertical section from front to rear; the other end againsta collarB and connected Fig. 4, a sectional plan, and Figs. 5, 6, 7, 8, to the shaft B by a removable pin 13, exerts 9, 10, 11, and 12 detail views. a constant tendency to thrust the shaft B in- 5 In the drawings similar letters of reference ward and to hold the finger B in contact with indicate like parts throughout the several the pattern 13 so that as the shaft B oscilfigures. lates, carrying the finger B over the pattern, The organization of the machine is such the configuration on the surface of the latter, that the mechanism which carries and rotates togetherwith the said spring, causes the shaft 0 the milling-tool limits its penetration and B to carry the work in and out under the governs and controls the extent of movement milling-tool, whereby the latter is caused to of the chuck or work-holder, Whether the latcut the required outline laterally, as will be ter be the one designed for holding flat or cyreadily understood. lindrical dies is the same, and thus in a single For adjusting the position of the work, in 5 5 machine is combined mechanism for sinking and out without interfering with the operaeither flat or cylindrical dies at pleasure, and tion of the foregoing mechanism, a rack B for convenience of description the machine fixed to the box B into which'the rack-pinion as a whole will first be described with rela- B carried on the shaft 13*, mounted in the tion to its operation as a machine for sinking framework of the machine and having the mo 50 dies upon a cylindrical surface-i. e., rollerhand-Wheel B is provided. By rotating dies. i the hand-wheel B the shaft B andits boxing Mounted in the groove are two stop arms or lugs C 0 held in the groove by clampingrequired position in the groove.

bolts 0, so that they may be adjusted to any For further nicety of adjustment the stop-arms are provided with contact-screws C tapped into said arms, so that said contact-points may be extended or withdrawn for minute adjustment by simply turning them. Standing in the path of these contact-arms is the arm 0 connected to the rock-shaft 0 mounted on the frame of the machine and carrying at its other end the arm C The latter is connected by the bar C to the lever O fulcrumed in the frame of the machine and'carrying at its other end the rod 0 said rod 0 being connected to a reversing-clutch which reverses the movement of the gearing that drives said plate 0 and consequently reverses the movement of said shaft B. The friction-clutch. is shown at C and is mounted to slide upon and rotate with the powershaft C Mounted loosely on this same shaft (1 are the opposing bevel-pinions C 0 meshing with the bevel-gear C keyed to the vertical shaft 0 lV'hen the clutch C is moved in one direction, it engages the pinion C and causes the shaft 0 to rotate with a corresponding rotation, and when said clutch is moved in the other direction it connects the pinion C to the driving-shaft and causes the rotation of the shaft 0 to 'be reversed. At the lower end of the vertical shaft C is a worm C meshing into a screw-gear 0", carried on the shaft O Mounted on this shaft 0 are a set of graded gears C any one of which may be connected to said shaft by means usually employed in such cases, as will be understood by reference to Fig. 4:, while the others will remain loose. On the sleeve 0 and connected to the plate 0 are corresponding graded work-holder or shaft B.

The cutting or milling tool and its relations and movements will now be described. The milling-tool itself is shown at D and may be of any of the ordinary forms of milling-tools or cutters. It is secured to the end of the rotating spindle D, mounted in the sliding head D which head in turn is fitted to slide upon the adjustable carriage D the latter being provided with a rack D, which is engaged by a pinion D for the purpose of feeding the milling-tool down by the means presently to be described to adjust it to a cutting position. Between the sliding head D and the adjustable carriage D is placed a spring v D which, added to the gravity of said sliding head, tends to keep the milling-tool pressed down to its work. The shaft D is splined to a pinion D which meshes with a pinion D carried on the driving-shaft 0 so that the milling-tool D is made to revolve rapidly and at the same time is free to move up and down. On the sliding head D is mounted a finger D for feeding a pattern D which pattern is mounted on the shaft B. This pattern D is for guiding the milling-tool in a vertical direction and is given a configuration corresponding to the varying depth to which the die is to be sunk. It will thus be seen that a angles to each other, the pattern I) guiding the milling-tool in the vertical plane and the pattern B guiding the work in the horizontal plane.

As it seldom happens that a matrix to be cut is shallow enough to be sunk by a single traverse of the milling-tool, it is necessary or desirable that means shall be provided for feeding the milling-tool downward a distance equal to what it can easily cut at each traverse. This feed is provided for by the rack D and pinion D fixed a hand-wheel D ,which is splined thereto and affords a means for turning the feed by hand when occasion requi'resas,for example, when it is desired to lift the milling-tool bodily away from the work. this feed shall be also capable of being or becoming automatic, I provide the shaft D, on which the pinion D is carried, with a bevelgear D which is mounted loose on the shaft, but which can be clamped thereto by a friction-clutch D carried on the hand-wheel D ,the clamping being effected when required by tightening up the hand-bolt D on the screwD. By this arrangement the bevel-gear D may be made tight or loose on the shaft at pleasure, according as the hand-feed or the automatic feed be used.

The feed-motion, when automatic, is im- To the shaft of the pinion D is In order that parted to the bevel-gear D as follows: A

short shaft carries at one end a bevel-pinion D", which meshes with the gear D and at the other'end a bevel-pinion D meshing at opposite sides with two loose bevel-pinions D D ,each of which pinions carries a ratchet D arranged for working in opposite directions by pawls D D said pawls being carried by the rock-shaft D. The end of this rockshaft is provided with an arm D which engages a fork D carried on the end of the sliding rod D, the other end of which rod is connected adjustably to the lower end of the lever 0 above described, and which is the lever that operates to reverse the gearing that drives the shaft B.

It will be seen, if the above explanation has been followed, that at each movement of the lever 0 and consequently-at each reverse of the movement of the work-holder or shaft B, the rod D is moved in one direction or another, causing the shaft D to rock in the same direction, and this motion of the rockshaft is transmitted by means of one or the other of the two ratchets into a rotary movement of the pinions D and D and the gear D and the shaft to which it is connected and which carries the pinion D so that the movement of the pinion D will be a rotary'movement of an intermittent character, always in the same direction, to feed the head carrying the milling-tool downward astated distance, and occurring at the beginning of each traverse of the tool on the work. In order that the amount of this feed may be regulated and adjusted to be greater or less, the connection between the rod D and the lever C is a slotted one, and an adjusting-screw D is provided for adjusting the amount of lost motion permitted, the length of the stroke of the rod D being inversely as the amount of lost mot-ion permitted.

By the foregoing mechanism it will be seen that when the automatic feed is applied the milling-tool will be fed down a stated and predetermined distance at the beginning of each traverse of the tool in the work and that the amount of this downward feed is capable of exact regulation to suit the requirements of the work.

To avoid the necessity of constant watching and repeated measurement and to provide against accidentally sinking a matrix toodeep, an automatically-operating feed-stop is applied to the tool-feed as follows: Connected to the tool-carrying head is a vertical rod E, working in a slide E and marked with distance-marks E, which may for convenience be, say, one-eighth of an inch apart for purposes of rough adjustment. This rod E carries adjustably secured to it an arm E bearing an adjustable contact-finger E for minuter adjustment. This contact-finger E is in position to strike against the short end of the lever E the long arm of which is connected by a rod E to the rod D which actuates the feed, so that when the tool-carrying head shall have descended far enough to bring the contact-finger E into contact with the lever the rod D will thereby be lifted so that its fork D is disengaged from the feed-operating rock-shaft D and the further downward feed of the tool therebystopped, although the machine will still continue to run.

For nice adjustment of the position on the rod E of the contact-finger, and in order that such adjustment may be clearly indicated to the eye and the position of the tool as to depth in the work at all times shown, a dialplate E is provided, which may preferably be marked off into spaces indicating a thousandth of an inch. A pointer E actuated bya cogged segment E is carried on a lever E the short arm of which is connected to the stop-arm E mounted on the rod E. By this arrangement the depth of the tool will be indicated on the dial and the setting of the stop-motion to work at the required depth is facilitated.

It sometimes happens or may happen that the speed of rotation given to the milling-tool is not great enough, even when thehighest speed is given of which the driving-shaft C is capable, Of course it will be understood that this condition is one which is only likely to exist when a very small milling-tool isemployed, because, as is well known, the smaller the diameter of the cutting-tool the higher should be its speed of rotation Within proper limits. A very small tool for operating in corners and narrow cavities should of course revolve at a very high speed to do good work. In this machine such a high speed of rotation of the milling-tool maybe very easily attained without interfering with the feed and driving operation as follows: On the lower end of pinion D which under ordinary circumstances is the gearing which drives the tool-carrying spindle D, is fixed a small band-wheel F,

grooved toreceive a cord belt, and provi-- sion is made for slipping on its shaft the pinion D out of mesh with its driving gear. or pulley. At each side of the' machine are guide-pulleys F F, and at a convenient point below is a large grooved band-wheel F mounted on a shaft F and provided with driving-pulleys F An endless cord (not shown in the drawings) passes around the small band-wheel F, over the guide-pulleys F F, and around the large band-wheel F Power applied to any one of the band-wheels F will of course transmit the motion of the band-wheel F throughtthe cord to the bandwheel F, and consequently to the spindle D and the tool D, and this speed may be as high as desired, as the movement is independent of the mechanism which operates the other parts of the machine and there is no necessary relation required between the rotary motion of the tool and said other motion of the machine.

surfaces, and when the machine is. to be 7 used for sinking diesuponplane surfaces said shaft B or cylindric work-holder is thus removed entirely from the machine, leaving the way clear for use of the plane-surface work-holderor chuck, which is located on the frame of the machine immediately beneath. This plane-surface work-holder or chuck, which may be permanentlyconnected with the machine and is so shown in the drawings, will now be described.

The chuck is organized to give to the work in a horizontal plane the following movements: first, a movement in a right line across the machine from side to side at a speed which may be adjusted; second, a movement transverse to and at any required angle to the first movement; third, a circular movement, the center of which may be adjusted to any desired point within the limits of :the other movements of the chuck, and, fourth,.compounds of any two or moreof the foregoing movements.

The chuck as a whole, aside from the devices which impart the movements, consists of four principal parts: first, a movable bracket .or support fromthe frame of the machineby means of which the chuck as awhole may be raised and lowered vertically .to suit the. exigencies of the work and to bring it into closer proximity to the. cutting-tool; secondly, a lower sliding bed-plate mounted on this bracket and adapted to move in a right line across the machine; third, a pivoted bed-plate pivoted to turn upon the lower sliding bedplate; fourth, an upper sliding bed-plate arranged toslide in ways upon the pivoted bedplate.

The means for giving movement to various parts consistsof a principal shaft lyingin the direction of movement of the lower bed-plate and carrying a splined bevel-pinion and a screw andreceivin g its rotary movement from the gearing of the machine, as will presently be described. The screw on this shaft is the means employed for givingthe right-line movement to the lower bed-plate, and the splined pinion sliding on the shaft meshing into acircular rack toothed on both sides, and which may revolve loose in or be locked to the pivoted bed-plate, is the means for communicating motion of arotary character to the pivoted bed-plate when locked thereto or when loose therein when transmitting power to the second screw-shaft to move the upper bed-plate.

Having thus stated generally the characteristics of the chuck as a whole, minuter description of the same willnow be given by the aid of the drawings.

G is the bracket or carriage, mounted to slide in ways G on the frame of the machine and capable of vertical adjustment by means of the screw .(P'turning in the nut G the latter supported from the frame of the machine.. This screw carries at its upper end a bevel-pinion Gflwhich engagesa bevel-pinion G on the horizontal shaft G the outer end of which is squared to receive a crank-handle, so that the screw may be easily turned by the operator in raising or lowering said bracket from a position in frontof the machine. The lower bed-plate of the chuck is shown at H and is constructed to slide in a right line.

bed-plate H, so that the rotation of said screw will move said bed-plate on its ways transversely across the bracket G in one or the other direction, according .to thedirectionof rotation of said screw. Splinedto the shaft H and carried in bearings on the bed -.p1ate H is the bevel-pinion H.

H is the pivoted bed-plate, held down :t0 the bed-plate H by the pivotal bolt 1-1 having the enlarged head H setting under a portion of said bed-plate I'I. Bolts H 9, passing down through the pivoted bed-plate H and having heads which engage thecircular groove H in said bed-plate H, afiord means for locking said pivoted bed plate to said bed-plate H whenever desired,so that said pivoted bed-plate may be left free to rotateon its pivot or locked fast in any position. Mounted loosely in the pivoted bed-plate H is :thecircular rack H having cogs on its lower ,sur-

face which engage the cogs of the bevel-pinion H, and having cogs on its upper surface which engage the bevel-pinion H this latter pinion being mounted loosely onthe shaft H, which carries the screw H, to which shaft it may be connected by means of ,a friction-clutch H operated by the screwnut H Said frictionclutch is provided with ahand-wheel H so that the screw H maybe operated independently of the pinion H when desired. Mounted on the pivoted bed-plate H is the upper sliding bed-plate H", connected to the screw H bya nut 1-1 On the surface of this upper sliding bed-plate H is mounted the movable jaw H which may be set forward by the set-screws H and locked in position by a bolt H the latter working through slots in the bed-plate. Opposing this movable jaw is a stationary jaw H and between these two jaws the work is to be held. On this stationary jaw H is mounted the guide, pattern H in position to be en gagedby the guide-finger D above described, carried upon the head which carries the milling-tool, and which guide finger determines'automatically the depth to which the milling-tool shall cut in the traverse of the work, when said cuts are not to be in the horizontal plane but of varying depth to suit.

some particular configuration.

ing with the bevel-pinion J, carried on the shaft J on the other end of which is the bevel-pinion J ,meshing with the bevel-pinion J", splined to the shaft J The gearing J J J 4 is all carried on the bracket Gand moves with said bracket, while the shaft J 5 is mounted on the frame of the machine. Hence the necessity for splining the pinion J 4 to said shaft in order that the chuck carrying bracket may be moved or adjusted up and down. On the upper end of the shaft J 5 is a bevel-pinion J meshing with the bevel-pinion J on the shaft J On the shaft J is mounted the co -wheel J which engages with one of aseries of graded gears J These graded gears J are mounted on the same shaft G which carries the graded gears G hereinbefore described, and consequently receive motion by the intermediate gearing above described of the same character and capable of the same regulation as that imparted to the work-holder shaft B when the latter is in use-that is to say, the shaft H which operates to move the chuck is by this means caused to rotate for a certain specified time and regulable amount first in one direction and then in the other, causing the work to traverse beneath the milling-tool and in a horizontal plane first in one direction beneath said tool and then in the reverse direction, whatever may be the line of its path, and of course it will be understood that the extent of this traverse may be regulated by the adjustment of the reversing-gear above described in relation to said workhold er shaft 13 and in the same manner.

The operation of the chuck is as follows: The work being clamped in the jaws on the upper bed-plate and the whole chuck being raised into proper position for the milling-tool to engage it and the extent of traverse required having been determined upon and the gearing for feeding and reversing set the machine is started and the required cut made. When it is desired to make a straight out in a direction across the machine, all of the parts of the chuck may be locked together and the feed of the upper screw thrown off. The chuck will traverse the work to and fro in a right line across the machine. However, if for any reason the line of cut cannot be made to coincide with the axis of the main feedscrew then the clutch of this main feed-screw may be thrown off and the clutch of the upper feed-screw set up to bring said upper feedscrew into operation and the upper bed-plate turned on the pivot until the upper screw will be in line with the required movement. The

pivoted bed-plate is then looked fast to the work a circular motion, the main screw being unclutched as well as the upper screw and the rectilinear feed being thus thrown off, the

pivoted bed-plate is released, so thatit shall become free to turn, and at the same time the circular rack H is locked fast by means of a set-screw K, (not before mentioned,) so that it cannot turn without also revolving said pivoted bedplate, and also revolving the upper bed-plate and the work carried thereby. The work will now have a horizontal rotary movement on its center coincidentto the axis of its pivot, and this center may of course be adjusted to any required position in a horizontal plane by means. of working with the hand-wheels one or both of the feed-screws; or, if desired, both of the feed-screws may be kept in gear and the pivoted bed-plate held rigid, when the movement of the work will be of course a compound or resultant of the two motions, or either one of these two motions may be compounded with the circular motion with a corresponding resultant. This makes the chuck most universal in its action, so far as cutting in a horizontal plane is concerned, and makes it peculiarly adapted to be operated in conjunction with the same milling-cutter, guiding and regulating apparatus adapted to be used with the oscillating work-holder and without in any manner interfering with said mechanism, so that either the horizontal plane chuck or the oscillating work-holder may be substituted in the machine, one for the other at will, and this together makes the whole machine one most admirably adapted to take its place in the shop as a universal diesinking machine capable of working either upon plane surfaces or cylindrical surfaces automatically.

The machine is also adapted for and can be used for drilling. To do this work, a continuous feed is employed instead of the intermittent feed heretofore described. To produce the continuous feed, the thumb-nut X on the shaft D is tightened on the miter-gear X, whichmeshes with a miter-gear X on shaft 0 9, thus imparting a continuous feed or downward movement to the shaft D and the sliding carriage D which carries the journalbox of the mill-spindle D. To efiect this, the adjusting-lugs C are also removed.

I claim- 1. In a die-sinking mechanism the combination of a continuously-rotating milling-tool holder, means for rotating the same, means for feeding said holder down at stated intervals at each traverse of the work, regulable means for reversing the direction of motion of the gearing which moves the work under the tool at each traverse of the work, together with means for connecting a removable oscillatory work-holder to said reversible driving- 7 shaft continuouslyrotating in one direction, 7 an automatic shifting clutch and dr'ivinggearing for changing the direction of the motion received from said driving-shaft, an adjustable automatic clutch-shifting device, a removable, oscillatory reversibly-traversing work-holder shaft, adapted to be connected to said reversible gearing, means for so con-- necting the same, and a horizontally-moving, to-an d-fro traversing chuck also connected to said reversible driving-gear, substantially as specified.

3. The combination with the oscillatory reversibly traversing removable work holder shaft, of the reversing-wheel carrying the adjustable clutch-actuating stops and mounted on a sleeve fitted to receive the end of said work-holder shaft and oscillate the same, substantially as specified.

4. The combination with the main drivingshaft, of two loose opposing beveled pinions mounted thereon, the sliding friction-clutch interposed between said pinions, the clutch- I actuating rod working in a cavity in the shaft and connected to said clutch, the lever connected to said rod, said lever being operated to move in opposite directions by stop-arms on a reversing-wheel, said reversing-wheel and its adjustable stop-arms, the bevel-gear meshing with the two pinions, its shaft, the worm carried thereby, the screw-gear on an intermediate shaft, and the series of graded gears to mesh. therewith on the reversingwheel, the whole constituting a mechanism for automatically converting the continuous rotation of the driving-shaft to an oscillatory movement, substantially as specified.

In a milling-machine, the work-holder shaft splined to the driving-gear so that it shall be free to more endwise, a spring for holding said shaft in one direction, a pattern mounted on a box in which said shaft oscillates, a feeling-finger mounted on and oscillating with said shaft, and means for moving the box bodily in and out carrying the shaft and its attachments therewith, substantially as specified.

6. In a milling-machine, the worleholder shaft splined to-the driving-gear so that it shall be free to move endwise, a spring for holding said shaft in one direction, a pattern mounted on a box in which said shaft oscilspecified.

7. The combination in a die-sinking machine of a milling-tool holder consisting of a shaft splined to its driv in g-gear and mounted in a sliding head, held down by a spring interposed between said head and an adjustable sliding carriage, and means for feeding said 1 carriage down toward the work, substantially as specified.

8. The combination in a die-sinking machine of a milling-tool holder consisting of a shaft splined to its driving-gear and mounted in a sliding head, held down by a spring interposed between said head and an adjustable sliding carriage, and means for feeding said carriage down toward the work, said means consisting of a pinion and shaft mounted on the frame of the machine and a rack affixcd to the carriage, substantially as specified.

9. The combination with the sliding and ing head ,provided with a do wnwardly-extending feeling-finger, of an oscillating workholder shaft carrying the pattern for guiding the tool in its up and down movements for contour, and said pattern mounted on the shaft and moved therewith, substantially as specified.

10. The combination of the automaticallyoperated reversing clutch-lever for reversing the driving-gear, of a connecting-rod connected to said lever and carrying a fork at its other end, resting on a rock-shaft carrying two ratchets geared to acoun-ter-shaft which in turn is geared to the head carrying the miliing-tool for feeding said milling-tool down to the work, and a stop-rod carrying an adjustable stop-arm arranged to come in contact with a lifting-lever connected to said beforementioned connecting-rod for lifting saidconnecting-rod out of contact with the rock-shaft, all combined and arranged substantially as specified and constituting an automatic feed too mechanism for feeding the milling-tool down a specified distance at each reverse of the driving-gear and for stopping saidfeed automatically when a certain depth has been reached, substantially as set forth.

11. The chuck comprising in combination the supporting bracket or base, the lower bedplate fitted to the slide thereon, a screw-shaft carrying a screw for giving motion to said lower bed-plate and carrying a pinion for giving motion to a circular rack, said circular rack having teeth on both faces, a second pint posed-circular rackhavi-n g teethon both faces, substantially as specified.

13. The universal horizontal movement chuck, consisting of a lower bed-plate mounted to be moved in slideways on its supporter base by means of a driving-screw, an intermediate pivoted bed-plate adapted to rotate on said lower bed-plate, and an upper bedplate adapted to slide on said pivoted intermediate and be moved thereon by means of 14. The combination with the screw-actuated lower bed-plate, of the bed-plate pivoted thereto, the circular rack, and means for locking said rack, the screw-shaft for driving the lower bed-plate and the pinion thereon mesh ing with the circular rack, substantially as I5 specified.

BENJAMIN JUDD ABBOTT. Witnesses:

H. M. MUNDAY, EDMUND ADcocK.

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