US498720A

US498720A - Machine

Info

Publication number: US498720A
Authority: US
Publication date: 1893-05-30
Anticipated expiration: 1910-05-30

Description

(No Model.) 4 Sheets-Sheet 1. A. MERTES. GEAR CUTTING MACHINE.

PatentedMay 30, 1893.

Y 4' Sheets-Sheet '2.

(No Model.)

' A. MERTES. GEAR CUTTING MAUHINE.

Patented m 30, 1893.

m: NORRIS rzrzns 00.. PhoTmuTnc" WASHINGTON, u c.

(No Model.) 4 Sheets-Sheet 3. A.. MERTES.

GEAR CUTTING MAGHINB. Dim-498,720. Patented May so, 1893;

(No Model.) 4 -Sheets-'-Sheet 4.

A. M'ERTES. GEAR CUTTING MACHINE.

No. 498,720. Patented MaySO, 1893.

UNIT D STATES AUGUST MERTES, OE ALLEGHENY, PENNSYLVANIA, ASSIGNOR TO THE A.

PATENT OFFICE.

MERTES MANUFACTURING COMPANY, OF SAME PLACE.

GEAR-CUTTING MACHINE.

SPECIFICATION forming part of Letters Patent No. 498,720, dated May 30, 1893.

Application filed January 9, 1892.

To all whom it may concern.-

Be it known that 1, AUGUST MERTEs, a resident of Allegheny, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Gear-Outting Machines; and I do hereby declare the. following to be a full, clear, and exact description thereof.

My invention relates to gear cutting machines, its object being to provide a form of apparatus which will have a greater capacity for work than the machines heretofore employed for this purpose, and one in which the cutting of the teeth can be done more accurately.

To these ends my invention consists in certain improvements and combinations of parts,

as will be fully hereinafter set forth and claimed. 7 V

' To enable others skilled in the art to make and use my invention, I will describe the same more fully, referring to the accompanying drawings, in which Figure 1 is a side view of my improvement in gear cutting machines. Fig. 2 is a rear end View. Fig. 3 is a front view. Fig. dis an enlarged view of the spring teeth which enter the several notches of the index plate. Fig. 5 is a top view of the rear end of the machine. Fig. 6 is a section in part on the line (66), Fig. 1. Fig. 7 is a top view of the rear end. Figs. 8 and 9 are detailed top views. Fig. 10 is a detailed perspective view. Fig. 11 is a detailed view of the mechanism for operating the clutch. Fig. 2 is an enlarged top view of the rear end showing the carriage in a11- other position. Fig. 13 is an enlarged rear end view. Figs. 14 and 15 are enlarged detail views; and Fig. 16 is a sectional viewof the shaft on the line 1616, Fig. 14:.

Like letters and figures indicate like parts in each view.

The frame A may be of any suitable construction, comprising the sides A the end pieces A and the standards A The power shaft Bis jonrnaled in suitable bearings in the ends of the frame A, and has secured to one end thereof the driving pulley 13 adapted to be connected up to asuitable driving shaft by means of the belt 13 The worms 0, O

and C are secured to the power shaft 13 at Serial No. 17,494. (No model.)

regular intervals, and said worms are adapted to mesh with the worm wheels D, D and D respectively. The said worm wheels D, D and D are mounted on the cross shafts E, E and E which are journaled in the journal boxes F in the sides A of the frame A, said worm wheels being mounted at the mid-point of said cross shafts. are secured to the cross shafts E, E and E In order to provide for the removal and the insertion of the cutters a, a, and a according asit is desired to cut the gears on diiferent sizes of wheels, the said cutters are secured to the spindles a Said spindles are provided'at their inner ends with the screw threads a adapted to engage with the threaded seat 0, in the cross shafts E, E, E The sliding carriage b rests upon'the frame A, and

is provided with the beveled flanges b adapted to travel along corresponding beveled flanges b on the sides A of the frame A. Any other suitable form of sliding connection between the carriage band the frame A may, however, be employed.

The plate 0, which, for convenience of illustration, will be termed a hanger plate, is secured to the sides b of the carriage b, said hanger plate being adjusted to move up and down on said sides 29 To provide for this =vertical adjustment of the hanger plate 0,

The cutters a, a and a said hanger plate is provided with the inwardly projecting lugs 0', having the screw threaded openings 0 therein. The screw bars a engage with the threaded openings 0 of the lugs c, and pass down through the sides b the collars c -being secured to the ends of said screw bars. The hanger plate 0 is formed with the vertical slots 0 with which the pins or bolts c on the sides 12 engage,said pins or bolts c having the heads or nuts 0 Itis thus apparent that by turning the threaded bars '0 in the proper direction, the hanger plate 0 may be raised or lowered as desired.

Depending from the hanger plate 0 are the hangers or brackets d, d, d These hangers d, d, d are formed in two sections, the section 6 being formed integral with the hanger plate 0, while the section e is hinged to the section e at e whereby a partible hanger or bracket is obtained.

In order to close the hangers d, d, (1 straps f are pivoted on both sides of the section e as at f. Journaled in the outer ends of the straps f are the eccentrics g, provided with the handles 9. When the hangers are closed, as 5 shown in Fig. 15, the straps f inclose the section e of said hanger, while the eccentrics g will be forced against the hinged section 6, and the twosections will thus be securely locked. A spring clutch g is secured to the 1 o hanger plate cabove each hanger, said clutch being adapted to receive the handle g when said handle is raised to open the hanger. The hangers d, d, 0Z form bearings for the reception of the mandrel h which carries the blank gear wheels'l, 2, 3 in which teeth are to be cut.

As the mandrel h carries the blanks, of necessity said mandrel must be capable of being readily removed to withdraw the finished gear wheels and to insert a new set of blanks to be out. To these ends, the forward end of said mandrel h is formed squarein the cross section as at h. When said mandrel h is in position, said square section h abuts against the shaft 7L2, which is also formed square in the cross section at 'its inner end, and said mandrel h and shaft 71 are adapted to be connected by any suitable coupling sleeve such as W, which may be tightened or released by turning the screw bolt 71/4. The shaft k be- 0 yond the square portion thereof is circular in form and is journaled in the bracket Zdepending from the hanger plate a, and said shaft carries at its forward end certain indexing mechanism, as will more fully hereinafter ap- 5 pear. The rear end of the mandrel h is held in place by means of the bolt j which passes through the abutment plate j which depends from the hangerplate c. The bolt j is threaded and said thread is adapted to engage with 40 the threaded openings in the abutment plate j. 'The inner end of said boltjis adapted to abut against the end of the mandrel h, a jam nut 9' being interposed between the head of said bolt and the abutment plate j. In this 5 manner when the mandrel h is in place by tightening the bolt j, the inner end thereof is forced against the end of the shaft h and acts to hold said mandrel against any longitudinal movement during the cutting operation. The mandrel 71. may thus be readily removed and again adjusted to place to hold the blanks in the proper alignment for the cutting of the teeth in said blanks.

In order to hold the blanks at proper inter- 5 5 vals upon the mandrel It, said blanks are separated in the following manner: A nut Zr; is secured on said mandrel and between said nut and the blank 1 is the tubular section 70. Between said blank 1 and blank 2 is another tubular section 70 and beyond said blank 2 is the collar 76 interposed between said blank and thehanger d. The blank 3 is interposed between the collar k and nut 70*. It is thus apparent that by tightening up the nut 70 the blanks 1 and 2 are held securely in place on said mandrel, and thus prevent any wabblin g on the part of said blanks. The same result is obtained by tightening up the nut 10 which secures the blank 3 in place.

To the front of the bracket Z, which depends from the hanger plate 0, is bolted or otherwise secured the face plate Z. The shaft it passes through said face plate Z, and beyond said plate and secured to said shaft 71, is the index wheel m.

To provide for the vertical adjustment of the face plate Z, said plate is formed with the slot Z through which the set screw Z securing said plate to the carriage 1) passes. By this arrangement the plate Z may be raised or lowered as may be desired.

The index wheel m is formed with notches or teeth m in its periphery, and said notches correspond in number to the number of teeth to be cut in the blanks, so that the index wheels, varying in the number of notches, are to be adjusted on the shaft 71, according to the number of teeth to be cutin the blanks.

Beyond the index wheel m on the shaft 71 is the sector plate 01. which fits loosely on the shaft h the teeth n on the inner periphery thereof. A pawl 12 is pivoted on said sector plate at one side thereof as at a said pawl n being adapted to engage with the teeth of the ratchet wheel 0 secured to the shaft 72?. The pawl n is held in engagement with the teeth of said ratchet wheel 0 by means of the spring 0. Pivoted at 0. tothe face plate Z is the sector arm 10, said sector arm having the teeth 19 adapted to engage with the teeth of said sector plate n. The opposite end of the sector arm p is provided with the idle roller p Directly above the index wheel 'm, and secured to the sliding carriage b, is the vertical guide q within which the detent q fits and is adapted to move up and down therein. A

This sector plate n is provided with.

spring g is interposed between the shoulders q within said guide q and the collar g on the detent q. The slot g is formed in the side of said guide q. The lower end of said detent q is provided with the finger g which extends below the guide q and is adapted to enter the several notches m of the index plate m.

Pivoted at s to the face plate Z is the bell crank lever 8. One arm 3 of said bell crank lever s is provided with the idle roller 3 fitted on the end thereof. A strap 8 secured to the face plate Z regulates the distance said arm 8 is permitted to move. The other arm 5 of said bell crank lever is provided with the lug s which is adapted to enter the slot g in the guide q, and said lug is further adapted to engage with the collar g on the detent q when said arm 8 is raised, as will more fully appear.

In order to operate said arms 8 and s to raise the detent q, a horizontal bracket or plate t. is secured to the stationary frame A, and on said plate is pivoted the arm 25. This arm 25 is held against any backward movement by the stud t on the plate t, while the spring i holds said arm firmly in contact with the stud 25 The arm 25 is provided with the inclined face t As the sliding carriage advances, the idle roller 3 comes in contact with the arm 25, as shown in Fig. 8, when said arm yields to allow said roller to pass, but immediately springs back to place after said roller has passed. On the return of the roller, when the sliding carriage recedes, as will more fully appear, the roller 5 travels over the inclined face i of the arm t which will operate to raise the arm 3 and consequently the detent q.

A bracket 'Lb is secured to the front of the frame A, and secured to that bracket u are guide strips a, if, the guide strips a being slightly above the guide strips "a strips 11/, a are formed with the end faces inclined as in a and w respectively. The idle roller p of the sector arm 19 moves in contact with the lower face of the guide stripu, and the upper face of the guide strip a as the sliding carriage advances and recedes, as fully shown in Figs. 9, 10, 12 and 13,in order to operate the index wheel m, as will more fully appear in the description hereinafter set forth.

In order to feed forward the sliding carriage b, a screw shaft '1) is journaled in the frame A, the threaded portion 1; of said screw shaft engaging with a nut '0 on said sliding carriage-b, whereby when said screw shaft is turned in said nut in the proper direction, the sliding carriage b is advanced. The power to rotate this screw shaft 1; for the advance of the carriage b is obtained indirectly from the mainshaft B. The shaft B is connected to the pulley w on the shaft 20 by means of the belt 10 A belt 10 connects the pulley 10 on said shaft 20' with the pulley 10 on the stud w while a pinion 20 on said stud meshes with the gear wheel 10*... This gear wheel to has secured thereto the pinion 10 which meshes with the gear wheel 10 on the screw shaft o. This gear wheel 10 is not secured to the screw shaft 1;,but is fitted loosely thereon, and is provided with the clutch face to. A clutch m is provided with a groove engaging a feather on the screw shaft '0 and adapted to slide to and fro thereon. A pulley :10 runs loosely on the outer end of said screw shaft '1; and said pulley 00' is furnished with a suitable clutch face x Abeltoc connects said pulley 0a with the pulley 00 on the shaft 10. When the clutch a: is in engagement with the clutch face w, the carriage will be advanced, and when the clutch 0c is in engagement with the clutch face 09 the carriage recedes.

The clutch a" is shifted from one to the other of said clutch faces 10 and x by the following form of mechanism. Alever'yis pivoted at one end thereof to an arm 1 extending out from the frame A. The lever y is furnished with a collar 1 adapted to engage with the annular groove y on said clutch 0c. The outer end of the lever y is secured to the rack 2 which rests on the sliding carriage b and fits in suitable guides thereon but does not move with the sliding carriage b. The rack z is The guide adapted to slide in the guides on the, said carriage- A wheel 2' provided with teeth a on all or a part of its periphery is journaled on a the carriage advances the clutch a: will be in engagement with theclutch 10 and since the toothed wheel 2' is mounted loosely on the stud e on the sliding carriage,it is evident that the toothed wheel 2 will. revolve, the rack z remaining stationary. The Weighted lever 57 being mounted loosely on the same stud as the wheel 2, upon the revolution of said wheel as the carriage advances the weighted lever will be carried through the are of the circle described by the rotation of the wheel 2. When the weighted lever a has passed the center of gravity, it will fall of its own weight, striking the stop 2 den falling of the weighted lever z on the stop 2 will impart a quick turn to the wheel 2. This suddenmovement imparted to the wheel .2 with its teeth engaging the rack 2' will act This sudto throw back said rack z a sufficient distance to throw the clutch :1: out of engagement with the clutch face to, and into engagement with the clutch face :0 The carriage b will then recede'to its former position with relation to the frameA. Any other suitable form of mechanism'for advancing the sliding car-- riage or withdrawing the same may be employed. J

The operation of my improved gear cutting machine is as follows; I have illustrated my invention in connection with a machine capable of cutting siX blanks, three on each side, at one time. It is apparent, however, that machines embodying the same principlesofconstruction could be constructed to have a greater. or less capacity. The

blanks

1, 2, 3, of the desired size, are arranged in the manner described and as shown in Fig. 1, on the" shafts h,'said shafts being locked in'the hangers d, cl, d by means of the eccentrics 9, while the boltj is tightened to press against the end of said shaft h to retain said shaft against longitudinal movement; has been adjusted on the shaft h with a number of teeth corresponding to the number of teeth to be cut in vthe blanksl, 2, 3. The

An index wheel m hanger plate 0 is adjusted at the proper cutters a, a, a are so adjusted on the spindles a that the teeth of each pairof cutters break joint with each other," that is, the teeth of the cutter on one end of one of the cross shafts which through the worms 0, G, (3 engaging with the worm wheels D, D, D acts to rotate the cross-shafts E, E, E In this manner the cutters a, a, a are driven.- Meanwhi1e,'the screw shaftr is rotated by the power transmitted from the main shaft B through the connections hereinbefore decribed, the

clutch :0 being in engagement with the clutch face to on the gear wheel As the carriage b advances, the

blanks

1, 2, 3 are'brought into contact with the cutters Ct, at, a when the cutting operation begins. During the advance of the sliding carriage b, the idle roller a at the extremity of the arm .9 overcomes the resistance of the spring arm and passes said arm which springs back to its normal position.

The roller p of the sectorarm p, as the carriage advances, moves along in contact with the lower face of the strip a and thence up the inclined faces a u and along the upper face of the strip of. As soon as the roller 19 travels up the inclined faces u a it is apparent that the end of the sector arm 10 carrying the roller 11 will be raised. I This movement of the sector arm p will act, through the teeth on said arm engaging with the teeth of the sector platem, to turn the sector plate 11 a sufficient distance tobring the pawl n pivoted to said sector plate into engagement with the next succeeding tooth'on the ratchet wheel 0. In the meantime, as the sliding carriage 12 advances, the wheel 2' has been making part of a revolution with its teeth 2 meshing with the rack z. The several parts have been so adjusted previous to the commencement of the cutting operation that just as soon as the cutters a,a',a have completed the respective teeth on the blanks brought into contact with them, the wheel 2' will have turned sufficiently to carry the weighted arm 2 beyond the center of gravity. The falling of the weight toward the forward end 'of the machine will throw back the rack z and with it the clutch a; into engagement with the clutch face 00 As the pulley 09 rotates in the opposite direction to that of the gear wheel U210, this engagement of the clutch m with the clutch face or? will reverse the rotation of the screw shaft '0 and cause the sliding carriage. to recede. When the carriage 1) begins to recede, the rollers 13 and s on the ends of the sector arm 1) and arm 8 respectively recede with it. The roller 19 recedes along the upper face of the guide strip 11?, and when said roller begins its descent down the inclined face u, the roller 8 will have traveled over the inclined face 15 The descent of the roller 19 down the inclined face a and thence along the lower face of the guide strip 71/ will lower the innerend of the sector arm 19 and consequently raise the end in engagement with the sector plate 12, to its normal or horizontal position, as shown in Fig. 3. The raising of the toothed end of the sector arm 10 to its horizontal position will impart a contrary movement to said sector plate to that imparted when the said sector arm ascended said inclined face M4 during the advance of the carriage. This will cause the pawl n which engages with the ratchet wheel 0 to ,turn said ratchet wheel and with it the index wheel m. The descent of the roller p down the inclined face a occurs after the roller 3 has traveled over the inclined face t of the arm 6, as stated. As the rollers meets said inclined face 15 the arm s of the bell crank lever s will be thrown toward the index wheel m, and the other arm 8 of said bell crank lever will be raised. By this action on the part of said bell crank lever the arm :5 will raise the detent q in the guide q and release the finger q from engagement with the index wheel m. The movement imparted to the index whheel m is sufficient to bring the next ttgoth in position to be engaged by the finger q bell crank lever s has traveled over the inclined face 25 of the arm 25' and has passed beyond the same, the force of the spring (1 will act to press down the detent q and throw out the arm 8 of the bell crank lever s hitherto in engagement with said detent. The finger g is then free to engage with the next succeeding tooth of the index wheel m, and in case said tooth has not already reached the point to be engaged by said detent q", said detent will rest upon the periphery of said index wheel, the spring g always forcing down said detent to allow it to drop into the next succeeding tooth of said index wheel when it has arrived at the proper point. It is, of course, apparent that as the index wheel m turns, the shaft h carrying the

blanks

1, 2, 3 will also turn a like amount. In this manner the blanks are turned a sufficient distance to provide for the distance between the several teeth to be formed in said blanks.

After the roller 5 on the arm 3 of the- By having the worm wheels D D and D mounted on the cross shafts E E E at the mid points thereof, the power is evenly distributed and the strain on the cutters is relieved while they also receive a more positive movement.

It is apparent from the construction shown and described that the several adjustable parts may be arranged to provide for the cutting of different sized gear wheels, as well as for different depths of teeth.

By having the spindles provided with cutters at each end, the cutting is even and regular.

What I claim as my invention, and desire tion with a suitable frame of one or more'revolving spindles carrying cutters, a reciprocat ng carriage,a hanger plate vertically adjustable on said carriage, and partible hangers on said hanger plate adapted to support a mandrel carrying blanks, and mechanism for turning said mandrel to bring said blanks into position for the next succeeding tooth, substantially as and for the purposes set forth.

2. In gear cutting machines, the combination with a suitable frame of one or more revolving spindles carrying cutters, a reciprocating carriage, a hanger plate vertically adjustable on said carriage, partible hangers on said hanger plate, and means for locking therein a mandrel carrying blanks, and mechanism for turning said mandrel to bring said blanks into position for the next succeeding tooth, substantially as and for the purposes set forth.

3. In gear cutting machines, the combination with a suitable frame of one or more revolving spindles carrying cutters, a reciprocating carriage, a hanger plate vertically adjustable on said carriage, hangers on said hanger plate adapted to support a mandrel carrying blanks and a shaft in line therewith connected thereto, an index wheel on said shaft, and mechanism for turning said index wheel whereby said shaft is turned to bring the blanks on said mandrel into position for the next succeeding tooth, substantially as and for the purposes set forth.

4. In gear cutting machines, the combination with a suitable frameof one or more revolving spindles carrying cutters, a reciprocating carriage supporting a mandrel carrying blanks and a shaft in line therewith connected to said mandrel, an index Wheel upon said shaft, a detent engaging with said index wheel, and mechanism for raising said detent and turning said index wheel, substantially as and for the purposes set forth.

5. In gear cutting machines, the combination with a suitable frame of one or more revolving spindles carrying cutters, a reciprocating carriage supporting a mandrel carrying blanks and a shaft connected to said mandrel, an index wheel on'said shaft, a sector plate beyond said index wheel, the said sector plate having a pawl adapted to engage with a ratchet wheel on said shaft, and mech anism for turning said sector plate, substantially as and for the purposes set forth.

6. In gear cutting machines, the combination with a suitable frame of one or more revolving spindles carrying cutters, a reciprocating carriage supporting a mandrel carrying blanks and a shaft connected to said mandrel, an index wheel on said shaft, a sector plate beyond said index wheel, said sector plate having a pawl adapted to engage with a ratchet wheel on said shaft, an arm on said carriage adapted to engage with said sector plate, and means for operating said arm to turn said sector plate, substantially as and for the purposes set forth.

7. In gear cutting machines, the combination with a suitable frame, of one or more revolving spindles carrying cutters, a reciprocating carriage supporting a mandrel carrying blanks and a shaft connected to said mandrel, an index wheel on said shaft, a sector plate beyond said index wheel, said sector plate having a pawl adapted to engage a ratchet wheel on said shaft, a toothed arm pivoted to said carriage .and adapted to engage with teeth on said sector plate, and means for operating said arm to turn said sector plate, substantially as and for the purposes set forth.

8. In gear cutting machines, the combination with a suitable frame, of one or more revolving spindles carrying cutters, a recipro cating carriage supporting a mandrel and a shaft connected to said mandrel, an index wheel on said shaft, a sector plate beyond said index wheel, said sector platehaving a pawl adapted to engage a ratchet wheel on said shaft, a toothed arm pivoted to said eari'iage and adapted toengage with teeth on said sector plate, the opposite end of said arm engaging with suitable guides whereby said arm is raised and lowered, substantially as and for the purposes set forth.

9. In gear cutting machines, the combination with a suitable frame, of one or more revolving spindles carrying cutters, a reciprocating carriage supporting a mandrel and a shaft connected to said mandrel, an index wheel on said shaft, a sector plate beyond said index Wheel, a pawl on said sector plate 1 adapted to engage with aratchet wheel on said shaft, a toothed arm pivoted to said carriage and adapted to engage with teeth on said sector plate, the opposite end of said arm carrying a roller, and guide strips on the frame with which said roller engages and which act to raise and lower said arm, substantially as and for the purposes set forth..

10. In gear cutting machines, the combination with a suitable frame, of one or more revolving spindles carrying cutters, a reciprocating carriage supporting a mandrel and a shaft connected thereto, an index wheel on said shaft, a detent on said carriage adapted to engage with teeth on said index wheel, a bell crank lever pivoted to said carriage, one arm thereof adapted to engage said detent, the other arm thereof being adapted to engage with an arm on the stationary frame, whereby the first mentioned arm of said bellcrank lever is adapted to raise said detent, substantially as and for the purposes set forth.

11. In gear cutting machines, the combination with a suitable frame, of one or more revolving spindles carrying cutters, a reciprocating carriage supporting a mandrel and a shaft connected thereto, an index wheel on said shaft, a detent on said carriage adapted to engage with teeth on said index wheel, a bell crank lever pivoted to said carriage, one arm thereof adapted to engage said detent, the other arm thereof being adapted to engage with an arm on the stationary frame,

IIO

said arm having an inclined face, whereby the first mentioned arm of said bell crank lever is adapted to raise said detent, substantially as and for the purposes set forth.

12. In gear cutting machines, the combination with the frame A, of the spindles a the reciprocating carriage b, the mandrel h and shaft h the index wheel m, the sector plate at, the pawl 91, adapted to engage the ratchet wheel 0, the toothed arm p pivoted to said carriage and adapted to engage with said sec tor plate, the roller 19 the guide strips a, a n the frame A with which said roller engages, substantially as and for the purposes set forth.

13. In gear cutting machines, the combination with the frame A, of the spindles a the reciprocating carriage b, the mandrel h and shaft 72?, the index Wheel m, the detent q, the bell crank lever s, the arm 8 thereof adapted to engage the detent q, the other arm 3 adapted to engage the arm 25, said arm having the inclined face 15 and being pivoted to the frame A, the stud t and the spring 15 substantially as and for the purposes set forth.

14. In gear cutting machines, the combination with a suitable frame, of one or more spindles carrying cutters, a carriage on said frame carrying the blanks to be cut, a revolving screw shaft engaging with a nut on said carriage, a gear wheel mounted loosely on said screw shaft and a pulley adapted to rotate in the opposite direction, and a clutch on said shaft adapted to be thrown into engagement with said gear Wheel and pulley to impart a reciprocating movement to said carriage, substantially as and for the purposes set forth.

15. In gear cutting machines, the combination with a suitable frame, of one or more spindles carrying cutters, a carriage on said frame carrying the blanks to be cut, a revolving screw shaft engaging with a nut on said carriage, a gear wheel mounted loosely thereon and a pulley adapted to rotate in the opposite direction, a clutch on said shaft, a lever engaging therewith, said lever being connected to a rack adapted to slide to and fro on said carriage, a pinion mounted loosely on a stud on said carriage and engaging with said rack, aweighted lever pivoted to said stud, and stops on said pinion with which said lever engages, substantially as and for the purposes set forth.

16. In gear cutting machines, the combinationwith the frame A, of the revolving spindles a carrying the cutters a, a, a the carriage b, a revolving screw shaft 0 engaging with the nut 0 the gear wheel 7,0 the pulley at, the clutch 0:, the clutch faces 00 w,

the lever y connected to the rack z, the pinion z the weighted lever 5 the stops 2 on said pinion, substantially as and for the purposes set forth.

In testimony whereof I, the said AUGUST MERTES, have hereunto set my hand.

AUGUST MERTES. Witnesses:

R0131. D. TOTTEN, J. N. CooKE.