US1320375A - Screw-driving machine - Google Patents

Description

S. K. BROWN.

SCREW DRIVING MACHINE.

APPLICATION FILED NOV. I. I9I6.

Patented Nov. 4, 1919.

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APPLICATION FILED NOV. 7. l9l6.

Patented Nov. 4, 1919.

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SCREW-DRIVING MACHINE.

Specification of Letters Patent.

Patented Nov. 4, 1919.

Application filed November 7, 1916. Serial No. iso,o41.

Z '0 all whom it may concern:

Be it known that I, SPENCER K. BROWN, a citizen of the United States,and a resident of Syracuse, in the county of Onondaga and State of New York, have invented a certain new and useful Screw-Drivi Machine, of which the following is a speci cation.

This invention relates to screw driving machines and has for its object a particularlysimple and efficient construction by which the screw is relieved when it has been driven to its final position and whereby it is immediately released of the driving force when the feeding pressure ceases, so that marring of the head of the screw is avoided; and the invention consists in the combinations and constructions hereinafter set forth and claimed. In describing this invention, reference is had to the accompanying drawings in which like characters designate corresponding parts in all the views.

Figure .1 is an elevation of-a portion of a f screw driving machine embodying my invention.

Fig. 2 is a longitudinal sectional view taken on the plane of line 2-2, Fig. 1.

Figs. 3 and 4 are enlarged sectional views taken on line 3-'-3, Fig. 2, looking in opposite directions.

Fig. 5 is a cross sectional view through the driving member.

Figs. 6 and 7 are respectively fragmentary sectional views and end elevations of the driven member when formed with a socket for hexagonal heads.

This screw driving machine comprises, generally, a guide for the screw, means for feeding the screws to the guide, mechanism for driving the screw including two sections, one ection including an axially movable member, actuating means connected to the other section, a friction clutch connecting the sections, a driven member movable axially to feed the screw engaging tool, a positive clutch connecting said members, the driving member having an axial movement relatively to the driven member to engage and disengage the clutch, means tending to.

normallyseparate said members and'to disengage the clutch, and means for feeding the driving and driven members axially.

1 designates the frame of the upper portion of a screw driving machine which frame is provided with a suitable foot 2 for attachment to a main frame or base.

3 designates the guide or holder for the screw, this guide or holder being supported by a bracket 4 suitably secured to the frame 1.

6 deslgnates a magazine chute by which the screwsare fed to the guide 3, the chute being 'connected at its lower end to a nipple 7 projecting at an inclined angle from the guide 3. The screws are fed one by one down the magazine chute 6 in any well known manner, and as this feature forms no partof this invention, and as the construction of such means is well known to those skilled in the art, further description 1s thought to be unnecessary, it being sufficlent to mention that during each upward axial feeding movement of the driving and driven members .of the screw driving mechanism, a screw is fed down the chute in front of the lower end of the driven member 1n posltion to be engaged by the driven member'during its next downward movement.

8 designates the driving member of the screw driving mechanism and 9 the driven member, these driving and driven members 8, 9 being arranged in axial alinement and movable axially to advance the screw, and to withdraw the driven member from the screw after the screw is fully driven. Said driven member 9 has its lower end normally arranged in the screw holder or guide 3 above the passage of the nipple 7 at the point it opens into the nipple 3, and said driven member moves across the lower end 11 of said passage during the feeding of the screw.

The driven member 9 may be provided with a detachable tool 12 for engaging .-a slotted screw head, or with a tool 13 having a socket for engaging a cap screw, as shown in Figs. 6 and 7. The screw is held in position to receive the screw driving tool by means of spring pressed puppets or balls 14 movable radially into the guide 3.

The clutch connecting the driven and driving members 8, 9 as here shown, includes interlocking teeth 15, 16 provided respectively on the opposing ends of the members 8. 9. the teeth 15 being pins extending parallel to the axis of the members 8, 9, from a head 17 on the member 8, and the teeth 16 on the-member 9 being the projecting ends of a pin extending diametrically through the upper end of the member 9 and located in an annular recess in a head 18. The heads 17 18 are connected together by suitable fastening members 19, and the member 9 is slidable in the head 18 during the relative axial movement of the members 8, 9.

20 designates a spring located in a socketin the head 17 and pressing in opposite directions on the head and on the upper end of the member 9, and normally separating said members and holding the clutch teeth 15 and 16 disengaged. I

The head 17 is secured to the member 8 by means of a threaded shank 21 screwing into an axial socket in the lower end of the member 8.

22 is the driving section of the screw driving mechanism, the driving section 22 and the member 8 are connected together by a friction clutch, the member 8 being movable axially relatively to the section 22 and the friction clutch.' As here shown, the driving section 22 is a gear wheel which is connected to a gear 23 mounted on the main driving shaft 24 by gears 25, 26 mounted on a shaft 27 The driving member 8 extends through the bore of the gear 22 and slides axially therein and the gear 22 is provided on its 1 upper face with an annular cavity 29 which is covered by a cap 30; and the friction clutch, with the spring for holding the same normally compressed is located in this cavity.

The friction clutch is here shown as a disk clutch including a set of disks 31 connected to the gear 22 to rotate therewith by means of ribs or flutes 32 extending in peripheral notches in the disks 31, and disks 33 interleaved with the disks 31 and having tongues 34 enteringperipheral grooves 35 in the driving member 8-.

The disks are held compressed together by means of a spring 36 pressing. at one end, against a compression plate 37 which compresses the disk together, and at its other end against an axially adjustable plug 38 threading into the cap 30. The plug 38 is held in its adjusted position by means of a lock nut 39.

The bearing for the member 8 in the gear 22.is rendered oil tight by means of a lead bushing 40 encircling the member 8 and having a head located in the countersunk recess in the upper side of the gear 22, the lead being poured into the bearing around the member 8, a washer 41 is interposed between the bearing 40 and the lower disk 34. The gear 22 is formed with a suitable hub 42 journaled in the bearing provided in 'a bracket 43 forming part of the main frame 1, the hub having a collar 44 'at its lower end for taking the upward thrust on-the gear 22.

The means for moving the driving and driven members 8, 9 axially comprises a lever 45 pivoted between its ends at 46 to a rocking fulcrum which in turn is pivoted at 47 to the main frame of the machine,

the lever being connected at its front end to the upper end of the member 8 and at its rear end to a link 48 which is connected at its lower end to a pedal not shown.

In operation, the members 8, 9 are constantly rotating, and the screw is first fed from the magazine into the chute 6 to the holder 3 where it is held by the spring pressed puppets 14. The foot pedal is then depressed to actuate the lever 45 which in turn moves the drivin and driven members 8, 9 downwardly a'xialTy until the end of the driven member 9 engages the screw held by the puppets 14 and further pressure moves the screw past the. puppets to the work.

When the resistance of the work to the screw prevents further pushing of the screw, additional pressure on the pedal causes the driving member 8 to depress relatively to the driven member against the action of the spring 20 and thus engage the clutch pin 15, 16 whereupon the screw is driven.

In case the tool is not in position to fit the slot or the cap of the screw when said tool first engages the screw, it will fit the slot or the .cap when the member 9 is turned part of a revolution. When the screw is completely driven and the operator is still holding his foot on the pedal the friction disk clutch will slip.

When the operator releases his foot after the screw is driven, the spring 20 causes the clutch pins 15, 16 to instantly disengage so that turning force is not transmitted to the tool and hence the tool will not mutilate the head of the screw when being taken out of engagement therewith.

What I claim is:

1. A screw driving machine comprising a frame, an element including two sections, actuating means connected to one section and the other section including upper and lower members, a friction clutch connecting. the said sections and the upper member of the said other section, said other section being movable axially relatively to the 'fricr tion clutch, a normally open positive clutch connecting the upper and lower members, the

positive clutch being movable into clutching engagement during relative axial movement of the upper and lower members when the lower member engages the screw and a .1

spring tending to separate the positive clutch sections, substantially as and for the purpose described.

2. A screw driving machine comprising a driving element including two sections, actuating means connected to one section, the other section comprising a spindle movable axially relatively to the former section, means connected to the axially movable section for engaging the screw, the section connected to the actuating means comprising a body having a central bore and a cavlty coaxial with the bore, the spindle of the axially movable section extending through the bore and the cavity, a disk clutch connecting the sections and located in the cavity, the disks connected to the axially movable section being slidably connected thereto to permit axial feeding of the driven section, and a spring in the cavity tending to compress the disks, substantially as and for the purpose described.

3. A screw driving machine comprising :a driving element including two sections, actuating means connected to one section, the other section comprising a spindle movable axially relatively to the former section, means connected to the axially movable section for engaging the screw, the section connected to the actuating means comprising a body havin a .central bore and a cavity coaxial wit the bore, the spindle of the axially movable section extending through the bore and the cavity, a disk clutch connecting the sections and located in the cavity, the disks connected to the axially movable section "being slidably connected thereto to permit axial feeding of the driven section, a sprin in the cavity tendin to compress the dlsks, the spring encirc ing the axially movable section, and an adjustable abutment for one end of the spring, the abutment encircling the axially movable section and threading into the other section, Eubastantially as and for the purpose speci- In testimony whereof, I have hereunto signed my name, at Syracuse, in the county of Onondaga, and State of New York, this 19th day of October, 1916.

SPENCER K. BROWN.

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