US1982492A - Nut blanking machine - Google Patents

Description

1934- S. BAXENDAI E 1,982,492

NUT BLANKING' MACHINE Filed. Jan. 19,1951 5 Sheets-Sheet l INVENTOR jaml/el fia/terrda Ze.

BYW

E ATTORNEYS- Filed Jan. 19, 1951 5 Sheets-Sheet 2 Mw w azzu k fi ll l H i: y H Nam n R 5a 255 my: 41677 a c, X

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S. BAXENDALE NUT BLANKING MACHINE Nov. 27, 1934.

Filed Jan. 19, 1931 5 Sheets- Sheet 3 a l NVENTOR Samuel at 617441 6.

BY #1524. W

ATTORNEYS Nov. 27, 1934. 5 BAXENDALE 1,982,492

NUT BLANKING MACHINE Filed Jan. 19, 1931 5 Sheets-Sheet 4 INVENTOR Samuel ,Eole fiddle BYVM-Mu Ml- ATTORN EY Nov. 27, 1934. 5 BAXENDALE 1,982,492

' NUT BLANKING MACHINE Filed Jan. 19, 1951 5 Sheets-Sheet 5 INVENTOR Samuel axefldale.

ATTORN EYS.

and while :thus clamped being operated upon by Patented Nov. 27, 1934 Patel rs-ice "1;Q82,492 NUT BLANIKING MACHINE Samuel 'Baxendale, Detroit, Mich, assignor, by direct and mesne assignments, to The Modern Collet & .Machine Company, Ecorse, Mich, a corporation of 'Michigan .A pplication January 19, 1931, Serial No. 509,825

8 Claims.

'lIlhe invention relates to nutblanking machines of that type in which a bar of stock is intermittently advanced within a rotating spindle, being clamped during intervals between advancements tools for boring, shaping and cutting off. The diameter of the :nut determined by the cross section of the stock par and its length :or thickness by the-amount it is advanced between clamping operations. Also the movement of the drill which bores the blank must be regulated to correspond :to this length or thickness.

In the present state of the art machines "of thisxcharacter have been provided with automatic 'means .for performing the several functions in proper sequence, but whenever the size of the nut is changed various adjustments are necessary. These adjustments require the attention of a skilled workman which increases the cost of manufacture. Furthermore, some of the parts of the mechanism employed are of a character to require :frequent adjustment or repair. It is therefore the :primary object of the present invention tolsimprlify the construction of the maf'25? chineand particularly to so simplify the adjustments for changing from one size of blank to anotherthat these may be performed by ordinarysunskilled workmenand quickly accomplished. A further object of the invention is to improve the construction of various parts of the mechanism rendering such parts more durable and more accurate in the performance of their respective functions. With these and other objects in view the invention consists in the construotionas hereinafter set forth.

In the drawings:

Figure 1 is a sectional side elevation of my improved machine;

Figure .2 is an enlarged longitudinal section through the mechanism for clamping the stock in the rotating spindle;

Figure :3 :is across section on line 33 of Fig-- chine is similar to machines of the type that have heretofore .been made comprising a bed .or frame A on which is mounted an electric motor Bhaving its rotor shaft C extending from'opposite ends and coupled with change gear trains (not shown) withinthe'housings D andD'. Extending longitudinally through the housing .I) is ithework carrying hollow spindle E which is rotated at suitable speed by the gear train in said housing. In axial alignment with the spindle'E is a drill spindle F which is revolved at the desiredspeed through a connection with'the gear train in the housing D.

The work spindle E which as before described is hollow has arranged therein an inner sleeve G for operating a radially contractible-collet H for clamping the stock. This collet is preferably formed with a conical head portion H for engaging a correspondingly tapered conical recess I in a collar 'l' at the end ofthe spindle E. The collet is slotted longitudinally to form a plurality or", preferably three, segments suitably fashioned on their inner faces to engage the polygonal outer face of the stock bar and the arrangement is such that when the conical head of the collet is drawn inward into the conical recess 1 it will be contracted to clamp the outer face of the bar and hold the same fi-xed in relation to the spindle. Inasmuch as various sizes of stock bars are used the collet H is exchangeable, having a threaded engagement at H 'with the sleeve G and thus whenever the change in size of blank is desired the collet may be detached and replaced by one of the proper size.

The sleeve Gextends to the outer end of the hollow spindle and has mounted on this end preferably by athreaded engagement therewith, the thrust bearing collar J. This may be adjusted in position on the threads and locked by a lock nut J. Upon the spindle E is a collar K having a plurality of pivoted cam levers K therein which as hereinafter described are operated to bear against the thrust collar J and to move the sleeve G for clamping the collet as previously described. I

Heretoiore stock clamping devices have been constructed employing the elements thus far described, but difiiculty has been encountered, first, in successfully using more than a single pair of cam levers; second, in equally dividing the load upon these cam levers and third, in avoiding rapid wear. I have overcome these defects by arranging three of the pivoted levers K equally distributed angularly around the collar K and to insure an equal loading of these levers have provided a universal pivotal thrust bearing for engagement therewith. Thus, as shown, the member J is provided on its rear face with a spherical segment J 2 which is engaged by a spherically concaved annular thrust member J The inner face of this member J is in a plane and directly receives the thrust from the cam levers K. Also the nose portions K of the cam levers K are preferably rounded or of a curve having no longer radius than that of the face J so that whenever the levers K are actuated the member J will adjust itself on the spherical bearing J to transmit equal pressure from each of the levers.

For actuating the levers K a grooved collar L is sleeved upon the spindle E and is provided at its forward end with a flaring portion L which engages the inner ends of the levers. The collar L is actuated by a lever M bifurcated to embrace the collar and engaging the groove thereof by roller bearings M. This lever is fulcrumed upon a bracket M on the frame and is actuated through the medium of a roller M by a cam groove M in the'peripheral face of a drum M actuated by the mechanism within the housing D. This cam is so timed with the other parts of the mechanism hereinafter to be described as to periodically actuate the collar L and through the levers K, thrust bearing J and sleeve G operate the collet H to clamp the stock bar therein.

The bar of stock may be of any length and is fed inward into the hollow spindle E whenever the collet is unclamped to permit such movement. The feed mechanism for the bar comprises a hollow guide tube N of sufficient length to receive the longest bar and slotted on its under side for the passage of a pin N. This pin is attached to a follower N which slides within the tube N but bears with its forward end against the end of the stock bar. The pin N outside of the tube N is attached to a cable 0 which passes over a sheave O and then to a winding drum 0 mounted on the frame of the machine. The drum 0 is hollow and has housed therein a spiral spring 0 which is wound up and placed under tension when the cable 0 is drawn outward, this tension being sufficient to feed the stock bar inward through the guide tube N. v

The tools for fashioning and cutting off the end of the stock bar to form a nut blank are of any suitable construction but as shown comprise the cutter P for chamfering the top side of the nutand for cutting a clearance in the polygonal corners on the bottom side of the adjacent nut. There is also a cutter P for completing the severing of the nut from the stock bar. These cutters are mounted upon slides P l? which are actuated by cams P, P driven by the mechanism within the housing D and suitably timed.

The thickness of the nut blank is determined by the amount of longitudinal movement imparted to the stock bar each time that it is released by the unclamping of the collet H. It is also necessary that the depth of the hole which is drilled in the nut blank should substantially correspond with this length of feed. Furthermore, whenever the thickness of the nut is changed provision must be made for a corresponding change in the length of feed of the stock bar and the depth of drilling.

struction easily adjusted and which is as follows:

The drill spindle F is provided with a drill chuck F for receiving drills of various sizes and is journaled in bearings F which permit both of rotation and longitudinal movement of the spindle. Clamped upon the spindle between these bearings is a collar Q having a projecting lug Q pivotally connected to a lever Q by a pin Q The lever Q is centrally longitudinally slotted at Q to receive a sliding bar Q pivotally engaging a pin Q on an adjustable fulcrum member Q The member Q engages a dovetail slot in a stationary bar Q and is adjusted in this slot by a screw Q engaging the threaded aperture in the block Q and swiveled at Q on the stationary frame. Thus by rotating the screw Q the pivot Q or fulcrum for the lever may be moved towards or from the pin Q The opposite end of the lever is bifurcated to receive a roller bearing R which on one side is engaged by a spring pressed plunger R and on the other side by a rod R which latter is actuated by a cam R to reciprocate the lever and through it the spindle F. The cam is timed with the rest of the mechanism and imparts a constant length of movement to the rod R but by adjusting the screw Q the amount of movement imparted to the spindle F can be varied to any extent between fixed limits. The cam is also fashioned with a portion R which causes a dwell or rest in the reciprocating movement of the lever in a position intermediate its ends for a purpose hereinafter explained.

Operation throw of the lever Q is determined by adjust-- ment of the screw Q which shifts the fulcrum bearing Q in the slot Q Thus the length of reciprocation of the drill spindle F is proportioned to the thickness of the nut blank which is to be formed. However, the length of this reciprocation is somewhat greater than the thickness of the nut sov as to provide clearance for disengagement of the nut after it has been severed but the length of reciprocation between the portion R of the cam and one end of the movement corresponds to the nut thickness.

After proper adjustment is made the stock bar is inserted in the guide tube N with its forward end engaging the sleeve G. The follower N is then drawn backward, the cable 0 being unwound from the spring actuated drum 0 to per-' mit of this movement, and the end of the follower is inserted in the guide tube N, the pin N engaging the slot in said tube. This will place a sufiicient tension upon the end of the stock bar to feed it forward whenever free to move. The forward movement of the bar is limited by engaging the end of the drill in the position where the as previously described this thickness may be varied by adjustment of the screw Q.

When the machine is started in operation the sequence of operations is as follows:

First, the lever M is actuated by the cam M to slide the sleeve L upon the spindle E in a direction causing the flaring end portion L to engage the ends of the cam levers K and move them inward. This causes the'nose portions K of the levers to move the bearing J rearward bartying with it the sleeve G and collet As has been fully described, the universal movement Of the member J on the spherical bearing J will distribute the load equally between the several levers K and as these are spaced at equal angles around the spindle, they are symmetrically arranged with respect to the axis of the latter and the sleeve G. This avoids overloading of any one lever and lessens wear. The movement of the collet H is only sufficient to effect the clampingof the same against the sides 'of thestock bar, thereby holding it rigid in relation to the spindle. Following this clamping of the stock the drill spindle F is moved by the cam SR .and lever Q to feed the drill into the end of the stock "bar and to drill a hole of the proper depth. The cam P then operates the :bar P to cause the tool P to schamfer the end of the stock bar after which the cam P actuating the bar P? moves the cutting off tool P inward to sever the blank from the bar. Before the completion of .thissevering movement the drill spindle has been moved in the opposite direction to withdraw the drill from the bored hole with sufficient clearance so that the nut blank whensevered will be free to drop. The spindle is then again moved towards the stock until the portion R of thecam is reached which holds the .drill in a position to form a stop for the stock bar and to gauge the thickness of the next nut blank. The cam M then 'actuates the leverM to release pressure of the cam levers K on the bearing J, therebyireleasingthe clamping action of the collet H and permitting the stock bar to be fedfforward by the tension of the any adjustment other than that of the screw Q which reduces or lengthens the reciprocation of the drill spindle F. Thus any workman without special mechanical skill can easily change the machine when necessary.

Another important feature of my improvement is the use of cam levers which are distributed around the work spindle and which engage a universal pivotal bearing so as to be equally loaded. This not only forms a much more positive actuation of the collet but also greatly lengthens the life of the parts by eliminating wear incidental to overloading any one member.

In the feeding of the stock bar by the mechanism described, there is an inertia element in the 1 drum and cable which delays the acceleration of the stock bar and thus limits the rapidity of its movement. To overcome this I preferably interpose a spring 0 between the cable 0 and the pin N. This spring will be extended and placed j under tension when the follower is first engaged with the stock bar and whenever the clamping collet is released the spring 0 will immediately feed the stock bar forward and before the inertia of the drum is overcome. Thus when the ma- .chine is used for rapid operation the time required for the feeding of the stock is reduced by this device.

What I claim as my invention is:

1. The combination with a revoluble spindle for receiving a stock bar and a collet for intermittently clampingsaid lbar within said spindle, of :m'eansifor feeding said bar through said spine dle when released by said collet-comprising ;a spring actuated rotary drum, acable wound on sa-id'idrum, adapted to be drawn off the same against the itensionofsaid spring, and a follower for engaging the end of the stock bar attached to the :end of said cable.

'2. The combination with a revoluble spindlefor receiving the stock bar and a collet for inter: mittentl-y clamping said :bar within said spindle, of means forfeeding the bar longitudinally in said spindle 'when released by said collet comprising .a spring actuated drum, a cable wound on said drum and adapted to be drawn on thewsame against the tension of said spring, aslotted guide tube in which said stock bar is supported, a fol-. lower insertable in said guide tube to engage the end of the stock bar .and a connection between the end of said cable and said follower passing through the slot in said guide tube.

3. The combination with a revoluble spindle for receiving a stock .bar and a .collet intermittently actuated to clamp said bar, means for feeding the stock bar through said spindle when released by said collet, means for fashioning and cu'ttingoff a projecting end of said stock bar when clamped bysaid collet, a drill and drill spindle for boring said stock bar, means for reciprocating said drill spindle to eflect the drilling and to withdrawsthe drill, a reciprocating member for aactuating said drill spindle arranged parallel thereto and having fixed limits of reciprocation, a l'lever intermediate said actuating member and said drill spindle connected thereto at "its :opposite ends respectively, a fulcrum engaging said lever intermediate its ends and means for shifting the fulcrum of said lever while mounted to vary the stroke of the spindle without change in the stroke of the actuating member.

4. The combination with a revoluble spindle for receiving a stock bar and a collet for intermittently clamping said bar, of means for advancing the bar through said spindle when released by said collet, means for severing a blank from the projecting end of said bar while clamped by said collet, a reciprocatory drill spindle in axial alignment with said revoluble work holding spindle, a drill carried by said drill spindle forming in one position of the latter a stop for limiting the advancement of the stock when released by said collet, a reciprocating member having a constant length of stroke arranged parallel to said drill spindle, a lever forming an intermediate connection between said reciprocating member and said drill spindle and connected thereto at opposite ends respectively, and a fulcrum for said lever adjustable independently thereof to vary the length of reciprocation of said spindle and tocorrespondingly vary the position of the drill when acting as a stop for the stock bar.

5. The combination with a revoluble work holder, means for feeding a stock bar through said holder and means for intermittently clamping the bar to said holder, of means for cutting off a blank from the projecting end of said bar while clamped in said holder, a drill spindle and a drill therein for boring said blank before the severing of the same, a reciprocating member for actuating said drill spindle arranged parallel thereto, a cam for actuating said reciprocating member and for imparting to the same a fixed length of stroke with a dwell at a point intermediate the ends of the stroke, a lever for communieating the reciprocation of said member to the 159 drill spindle and a fulcrum for said lever adjust able independently thereof to vary the stroke of said spindle, and to correspondingly vary the position of the drill during the dwell between limits of reciprocation whereby the drill forms a stop for the advancement of the stock and gauges the thickness of the blank cut ofi.

6. The combination with a revoluble spindle for receiving a stock bar and a collet for intermittently clamping said bar within said spindle, of means for feeding said bar through said spindle when released by said collet comprising a spring actuated rotary drum, a cable wound on said drum adapted to be drawn off the same against the tension of said spring, a follower for engaging the end of the stock bar and a spring intermediate said follower and the end of said cable for the purpose described.

7. The combination with a revoluble work holder, means for feeding a stock bar through said holder and means for intermittently clamping the bar to said holder, of means for cutting off a blank from the projecting end of said bar while clamped in said holder, a drill spindle and drill therein for boring said blank before the severing of the same, a reciprocating member for actuating said drill spindle arranged parallel thereto, a cam for actuating said reciprocating member and for imparting to the same a fixed length of stroke witha dwell at a point intermediate the ends of the stroke, a lever for communicating reciprocation of said member to the drill spindle, a fulcrum for saidlever adjustable independently thereof to vary the stroke of said spindle and to correspondingly vary the position of the drill during the dwell between limits of reciprocation whereby the drill forms a stop for the advancement of the stock and engages the thickness of the blank cut off, said fulcrum engaging a slot in said lever, a fixed bearing in which said fulcrum is adjustable longitudinally of said lever and a screw for adjusting said fulcrum in said fixed bearing.

8. The combination with a revoluble work holder, means for feeding a stock bar through said holder and means for intermittently clamping the bar to said'holder, of means for cutting off a blank from the projecting end of said bar while clamped in said holder, a drill spindle and a drill therein for boring saidblank before the severing of the same, spaced bearings in which said spindle is longitudinally and rotatively movable, a collar secured to said spindle intermediate said bearing, a reciprocating member for actuating said drill spindle arranged parallel thereto, a cam for actuating said reciprocating member and for imparting to the same a fixed length of stroke with a dwell at a point intermediate the ends of the stroke, a lever pivotally secured at one end to said collar and pivotally engaging said reciprocating member at its opposite end, said lever being slotted longitudinally intermediate its ends, a block slidably engaging said slot, a fulcrum pin pivotally engaging said block, a member to which said pin is secured, a fixed bearing slotted in a direction longitudinally of said lever for receiving said member, and a screw engaging said member to adjust the same in said slot.

SAMUEL BAXENDALE.

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