US2408686A - Machine for slotting screws - Google Patents

Description

00b1, 1 946. I RUSH k 2,408,686 MACHINE FOR SIJOTTING SCREWS Filed Dec. 26, 1944 s Sheets-Sheet 1i Oct. 1,1946. J. A. RUSH 2,408,686 1 MACHINE FOR SLOTTING SCREWS 7 Filed Dec. 26, 1944 s Sheets-Sheet 3 MA 62 66 v 6459 Y Y Patented Oct. 1, 1946 John A. Rush, Milton, Ontario, Canada, assignor to P. L. Robertson Mfg Ontario, Canada 00., Limited, Milton,

Application December 26, 1944, Serial No. 569,887

This invention relates particularly to machines for slotting the headsof screws and the principal object is to overcome the difilculties .met with in removing the screw blanks from a feed hopper and conveying them to the slotting 12 Claims. (01. 10-5) the hopper and feed mechanism taken on the means without jamming, thereby ensuring a regular progression of blanks to the slotter and obviating the losses encountered through machines operating idly, thereby effecting aconsiderable increase in output of the machines and eliminatin considerable cost. in excess attendance of operators. 7 I g V A further object of the invention is to ensure the positive holding and accurate slotting of the screws and to enable material increase in the speed of production and the output of the machine. a I "'.'I'he principal featured the invention consists in the provision-of an elevator mechanism leading from a hopper, in which a pair of parallelly arranged inclined rollers, spaced-apart and having opposing spiral surface grooves, are rotated in opposite directions to engage the heads of the screw b-lanks with the shanks thereof depending between said rollers and torcarry the blanks upwardly, said elevator delivering the screw blanks,

heads upward, to a downwardly inclined guide which delivers the blanks to a separating and A further feature of importance consistsin the .novel arrangement of a rotating member provided with radial arms to move upwardlythrough the mass of screw blanks in the hopper preventing the jamming thereof in the entrance to the slot between the-inclined rollers.

Another feature of importance consistsin the it novelmeans for periodically rotating the screwholding member and the synchronous operation of the slotting saw to engage the blank heads between the periodic movements of the holder.

And a still further feature is in the provision of a synchronized gripper means ,for holding the blanks securely during the cuttingoperationof thesaw In the accompanying drawings I Figure 1 is a plan view of a portion of my hopper.

a Figure 3 is a part vertical sectional view through line 3%3 of Figure 2. I

Figure 4 is a sectional elevational View of the machine taken on the line'4--4 of Figure 1 particularly showing the screw blank feed' mechan1sm.- 7

Figure 5 is an elevational detail of the gear mechanism 'for operating the elevator members. Figuref6 is an enlarged plan detail of a portion ofthe cylindrical blank elevator members. Figure? is a detail elevational view of a portion'of one of the blank feed elevators seen from the line "ll of Figure 6 showing the,screw blanks in position as suspended between the elevators.

Figure 8 is a detail sectional view taken through the elevators on theline 8-8 of Figure 6.

Figure 9 is a part sectional detail of the slotting saw-operating mechanism taken on the line 99 of Figure 1.

Figure 10 is apart sectional detail of the blank griper me'chanisr'n'taken on the line Ill-I0 of Figure l. I

I Figure 11 is a plan detail of the ratchet mechanism for rotating the blank holder.

Figure 12 is a broken elevational detailof the means for actuating the rachet rotating means taken on the line l2--l2 of Figure 1.

various types of screw slotting machines it has'been customary to place the headed screw blanks in a hopper and feed them in an angular direction downwardly to the slotting mechanism and such machines, although provided with means for agitating the blanks in the hopper to cause them to'enter the feed slot, have been found to jam frequently allowing the slotting mechanism to operate idly,- thereby causing a considerable loss in-efliciency even though subject to constant vigilance and attention on the part of the attendahts and the present invention has been devised particularly to obviate this condition.

In the construction of machine herein illustrated a base section I of the frame of the machine is provided at one side with an obtuse angled bracket support 2 and a parallelly arranged angled. bracket 3 intermediate of the width of the machine mounted on a vertical support 4.

A pair of parallel rollers 5 are supported in an inclined position with the lower ends journalled in the bracket 2 and their upper ends journalled in the bracket 3. These rollers 5 are spaced apart a distance sufiicient to permit the shank of the screw blank of the size for which the machine is designed to fall freely therebetween but the slot 6 formedtherebetween will not permit the 3 heads to pass and the bottom perimeter l of the screw blanks will ride on the surface of the rollers.

The rollers 5 are each formed with a spiral groove 8 which grooves are respectively right and left hand spirals and are of a width and depth to accommodate the particular blank heads so that the perimeters of said heads will engage the edges of the grooves and ride therein as particularly illustrated in Figures 6, '7 and 8.

The lower journal ends of the rollers 5 extending through the bracket 2 are provided with spiral gears 9 which are of respectively right and left pitch and mesh with spiral gears Ill mounted on a shaft ii journalled in lugs l2 extending from the bracket 2.

The shaft I I is shown driven by a belt and pulley connection with a shaft 13 journalled in the frame of the machine. a

A pair of parallelly spaced-apart guide bars l4 rigidly mounted on the vertical support 4 and a similar but shorter vertical support 15, lead angularly downward away "from the upper ends of the spirally grooved rollersi', the upper ends thereof being adapted to receive the heads of the screw blank as they reach the upward limit of the spirally grooved rollers 5 and are dropped therefrom. v

A toothed wheel l6 mounted on an adjustable arm ll pivotally mounted on the bracket 3 is adapted to rotate in a direction toward the bracket 2 and acts as a spacer to prevent the blanks from slidingdown the guide bars 14 in a close l packed string. The shaft ii on which the wheel I6 is mounted is driven by a belt I8 operated from a pulley mounted on the shaft I3.

Arranged above the elevator rollers 5 and suitably supported from the brackets 2 and 3 is a trou h-shaped hopper I9 formed with an open slotted bottom 29 which directs the screw blanks on to the convexed top surface of the rollers 5 so that the shanks thereof will be guided into the slot 5 between the rollers and the heads will engage the roller surfaces and be supported thereby.

A storage hopper extension 2] is arranged at one side of the hopper l9 and feeds blanks through an opening controlled by a suitable gate 22.

A shaft 23 is suitably journalled transversely of the lower end of the hopper and carries a disc 24 from which radial arms 25 extend. The arms 25 are preferably curved and as the disc is rotated they dig into the mass of blanks in the bottom of the hopper and lifting upwardly on same continuously separate said blanks so that the shanks will fall into the slot 6 between the rollers 5 thus causing the blank heads to be engaged by the continuously upwardly travelling spiral grooves of said rollers. The result of the operation of this elevator mechanism is that there is a continuous procession of screw blanks being picked up by the grooved rollers and carried upwardly and discharged at the upper end into the downwardly sloping guide formed by the bars I4.

The shaft 23 is shown provided with a worm wheel, 25 which meshes with a worm 21 on a vertical shaft 28 which is driven by meshing spiral gears 29 operatively connected with the shaft I l.

The screw blanks sliding down the guide bars l4 enter notches 30 in a member 3| rotatably mounted in a bracket 32. arranged in right angular relation to the guide bars l4. A part circular guidemember 33 partly encloses the notched head of the member 3| and holds the screw blanks within the notches as the member 3| is rotated as hereinafter described.

Parallel cross frames 34 and 35 extending transversely of the machine (see Figure 1) support the main drive shaft 36 on which the pulleys 3'1 and 38 are mounted and on the shaft 35 is pivotally mounted a frame 39 carrying bearings in which the slotting saw shaft 40 is journalled, the saw 4i being arranged above the notched head of the rotary member 3| in a position to engage and slot the heads of the screw blanks carried by said rotary member.

The pivotal frame 39 is provided with a downwardly extending shoe 41' (see Figure 9) which engages a member 42 pivotally mounted on a pivot pin-43 extending from the side of the cross frame 34. The member 42 is provided with an adjusting screw 44 which engages a member 45 also pivoted on the pin 43 and the member 45 is formed with a socket in which a rod 46 pivotally engages.

The bar 56 is secured in a lug 41 on an arm 48 pivotally mounted on a fixed pivot pin 49.

The free end of the arm 48 is provided with a roller 58 which engages the peripheral surface of a cam wheel 51 carried on a shaft 52 suitably journalled in the cross frames 34 and 35.

A bar 53 is supported :between the cross frames 34 and 35 parallel with the main drive shaft 36 and on said bar is slidably mounted a sleeve 54 which is held from rotation by a forked arm extension 55 engaging a collar sleeve 56 mounted on a cam shaft 5'! journalled in bearings in the cross frames 34 and 35 and arranged parallel with the shaft 54.

A face cam 58 mounted on the shaft 51 engages a roller 55 mounted on a stud extending laterally from the sleeve 54 and imparts longitudinal movement to the sleeve 54, the roller being held in contact with the cam by a coiled spring 6Q connected to an arm 6| extending downwardly from the sleeve 54.

Connected with the downward extension Bl of the sleeve 54 is a rod 62 which extends to and is connected with a ratchet mechanism for operating the. rotatable blank-holding member 3!.

Secured to the lower end of the member 3! are a pair of spaced ratchet wheels 63 and 64 having their teeth oppositely arranged, and rotatably secured on the bracket 32 housing the member 3| is a ring 65 having a lug extension 65'. to which the rod 62 is connected.

The cam 58 moves the .rod 62 positively to rotate the ring 65 in one direction and the return movement of the rod is effected by the pull of the spring and such poll is therefore flexible.

Pivotally mounted on the ring is a ratchet dog 66- which is held in engagement with the ratchet wheel 64 by a coil spring 64. This dog slips freely over the teeth of the wheel 64 as the rod is operated by the cam but on the return spring-operated movement of the rod 52 the dog 66 engages and rotates the ratchet wheel and thus performs the indexing movement of the blank holder.- In the event of a blank jamming in the rotating holder the rod 62, being spring operated will not force the member 3|, consequently the ratchet and the member 3| will not be rotated the desired indexing distance and it is desirable that the member 3i be freed.

A dog 61 pivotally mounted on the ring 65 is adapted to engage the teeth of the oppositely toothed ratchet 64 and, as thecam 58 continues its cycle it moves the rod 62 to rotate the ring to bring the dog 61 into operating engagementwith the ratchet wheel 63 and thus pushes the'member 3| backward. If the member is not; then rfreed the back and-forth ratchet action will be repeated until it 'freesthe rotary holder and the indexing dog again picks up the motion.

It is important that the member 3| should be held securely in the proper indexed position and dogs Gil-and 69, oppositely arranged and supported engagethe teeth of the respective ratchet wheels. a

The dog 68 is disengagedby the contactof a pin 68 on the ring to swing the dogclear at the proper period and the pivotsupport of'the dog 69 is provided with a pin 69 which is engaged by a-spur on the dog 61 to lift it out of engagement with the ratchet wheel .63 at the proper period to permit the rotation of the-blank holder 3| by the indexing member. This double arrangement of ratchet dogs and pawls ensures the positive movement of the blank holder a definite distance with each movement of the rod 62 so that the blanks held in. the notched member 3| will be moved to a positive position centrally belowthe slotting saw, thus ensuring the slot being cut accurately across the diameter of the screw head. The ratchet mech-anism'for rotating and posi tioning the member 3| is such that on each rotation of the cam 58 the member 3| is moved the distance between two adjacent blank-holding notches and the blank in the succeeding notch is brought into register with the slotting saw.

Immediately prior to the operation of the arm 48 by the cam 5|, to withdraw the rod 46 to permit the swinging of the saw carrying member downwardly to out the screwhead, it is necessary that the screw blank be held rigidly to permit the proper action of the saw in slotting same.

Pivotally mounted on a lug extending from the housing of the rotatable member 3| is a dog H which is adapted to be swung toward the notched blank holder to engage and grip the shank of the blank to hold it rigidly while the saw descends in its cutting operation. e

A shaft 12 secured to the locking dog 1| has mounted thereon an arm extension 13 which is adjustably connected to a rod 14 which is connected to a pivotal lever arm 15, said lever arm having a roller end engaged by a cam disc 16 mounted on the shaft 52. Q

It will be, readily understood that upon each revolution of the face cam 58 the sleeve 54 will be moved longitudinally .on its support to operate the ratchet mechanism for turning the member 3| the required distance to bring ablank directly beneath the saw.

The cam disc 16 then operates the locking dog II to pinch the blank tightly in the holder and immediately following this operation the cam 5| operates the dropping of the saw and after a brief period, sufiicient for the cutting of the slot in the screw blank, the cam 5| operates to tilt the member 42 to raise the pivotal saw frame 39 to clear the blank.

The locking dog H is then released and the operation of the cam 58 and its co-related mechanisms is repeated.

It will be understood that the elevator mechanism comprising the rollers 5 and the-hopper clearing disc 24 operate continuously and the blanks are picked up from the slotted hopper and carried in a continuous procession upwardly and then discharged between the guide bars l4 and. the blanks feed into the notches in the member 3| successively when said member. is periodically moved. r After the screw blanks have been slotted they are discharged from the member by a suitable wiping finger to clear them zfromlthe notches, such delivery device not being shown as it is a common expedient. A device such as described forms a compact and very reliably operating machine which operates continuously giving the maximum output with the minimum of attention. It will be readily understood that the blank feeding mechanism described may be utilized in machines other than slotters, that" is to say, it may be used to feed headed blanks to threading machines or in fact it may be used to feed any form of headed blank to a machine for other operations as may be desired providing a con tinuous flow of blanks to any machine, where such may be required.

,What I claim as my invention is: i 1. Means for feeding'blanks having a head and a projecting stem, comprising a pair of parallelly arranged rotatable inclined cylindrical members spaced apart to permit the entry of the shanks of the blanks to be fed, the heads of the blanks engaging the peripheries of the cylindrical members, the blanks being loosely suspended between said members, said cylindrical-members having respectively right and left spiral peripheral grooves adapted to engage the blank heads, means for rotating said cylindrical members invopposite directions in unison to advance the blanks up: wardly and deliver same successively, and a downwardly inclined slotted guide arranged to receive the shanks and support the blank heads.

2. In a device as claimed injclaim .1, means arranged at the lower end of the downwardly inclined guide adapted to receive the blanks and carry same from the guide to be operated upon. 3. A machine for slotting screws comprising inclined rotatable cylindrical means spirally grooved and adapted to engage the heads of said blanks and hold them suspended and carry same upwardly, a downwardly inclined slotted guide extending from the upper end of'said rotatable blank-carrying means and adapted to guide the screw blanks, a peripherally slotted member r0- tatably arranged at the lower end of said downwardly inclined guide adapted to receive the screw blanks delivered from said inclined guide, means for periodically rotating said slotted rotatable member, and means operating periodically to slot the heads of said blanks between the periodic rotating movements.

4.'A machine as claimed in claim 3 having means for gripping the screw blanks in said slotted rotatable member during the slotting operation.

5. In a machine as claimed in claim 3, a grip- I per member pivotally mounted adjacent to said slotted rotatable blank-holding member, and

cam-operated means for periodically swinging said gripper member to engage and lock each blank during the slotting operation.

6. A device as claimed in claim 3, in which the means for slotting the heads comprises, a frame pivotally mounted to swing upwardly and downwardly, a saw shaft journalled in said frame and extending over said slotted rotatable blankholding member, a saw mounted on said shaft, and cam-operated means for lowering and raising said saw-carrying frame to effect the slotting of the blank head.

7. A device as claimed in claim 3, in which the means for slotting the heads comprises, a frame pivotally mounted to swing upwardly and downwardly, a saw shaft journalled in said frame and extending over said slotted rotatable blankholding member, a saw mounted on said shaft, a member pivotally mounted adapted to engage and lift the pivotal saw frame, a pivotal lever operatively connected to swing the aforesaid saw frame lifting member, and a cam operatively engaging said pivotal lever to periodically lower the saw frame coincident with the periodic stopping of the rotatable blank-holding member.

8. In a device as claimed in, claim 3, a rotatable toothed wheel mounted above the downwardly inclined slotted guide having its toothed periphery engaging the heads of the blanks sliding down said guide and periodically retarding their downward movement.

9. A device as claimed in claim 3, in which the means for periodically rotating the slotted blank-holding member comprises a ratchet mechanism attached to said slotted rotatable member, a reciprocable member connected with said ratchet mechanism, a cam operatively engaging said reciprocable member, and a spring for reversing the movement of said member.

10. A device as claimed in claim 3, in which the means for periodically rotating said slotted rotatable member includes a pair of ratchet wheels secured to said member, a rotatable ring mounted between said ratchet wheels, dogs pivotally mounted on said rotatable ring engaging each of said ratchet wheels to rotate said slotted member in the oscillating movements of said ring, pawls engaging each of said ratchet Wheels and holding same at the end of the oscillating movements, and cam-operated means for imparting oscillating movements to said ring.

11. Means for feeding blanks having a head and a projecting stem, comprising a pair of parallelly arranged rotatable cylindrical members spaced apart to permit the entry of the stems of the blanks to be fed with the peripheries enspectively right and left spiral peripheral grooves adapted to receive the perimeter of the blank heads, and means for rotating said cylindrical members in opposite directions in unison to advance the blanks and deliver same successively, a hopper with an opening therein to deliver blanks to the upper surfaces of said grooved cylindrical members, a shaft journalled transversely of said hopper, a disc mounted on said shaft having radial arms extending into said hopper, and means for rotating said shaft.

12. A screw slotting machine comprising a frame, a drive shaft journalled longitudinally in said frame, a saw shaft frame pivotally mounted axially of said drive shaft, a saw journalled longitudinally in said pivotal frame, a hopper mounted transversely of said frame, a pair of parallel spaced-apart inclined spirally grooved cylindrical members journalled transversely of said frame beneath said hopper, a downwardly inclined slotted guide extending from the upper deliveryend of said pair of spirally grooved cylindrical members, a, rotatable blank-holding member arranged at the lower end of said inclined guide, a saw on said saw shaft arranged above said slotted rotatable member, means for locking screw blanks in said rotatable member, a cam shaft journalled longitudinally of the main frame having a cam thereon, means operated by said cam for operating said locking means, a saw frame operating cam mounted on said cam shaft, means operated by the latter cam for lowering and raising said saw frame, ratchet means for rotating said slotted rotatable member, a guide arranged longitudinally of said main frame, a member slidable on said guide operatively connected with said ratchet means, a cam shaft J'ournallecl longitudinally of said frame, a cam on said cam shaft adapted to operate said ratchetoperating slidable member, and means for rotating said inclined rotatable spirally grooved members in opposite directions to feed screw blanks upwardly from said hopper to said ingaging the heads and holding the blanks loosely clined guide.

suspended, said cylindrical members having re- JOHN A. RUSH.

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