US1157969A - Screw-driver. - Google Patents

Description

J. H. TOBIN.

SCREW DRIVER.

APPLICATION FILED FEB. 5, 1914.

Patented Oct. 26, 1915.

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JOSEPH H. TOBIN, F DERUYTER, NEW YORK, ASSIGNOR '10 MESSENGER SCRE'W 00., INQ, 0F LINCKLAEN, NEW YORK, A CORPORATION.

SCREW-DRIVER.

Specification of Letters Patent.

Patented Get. 2%, F915.

a lication filed. February 5, 1914. Serial No. 816,705. i

To all whom it may concern Be it known that l, J osnrn H. TOBIN, of Deruyter, in the county of Madison, in the State of New York, have invented new and useful improvements in Screw-Drivers, of which the following, taken in connection with the accompanying drawings, is a full, clear, and exact description.

This invention relates to certain improvements in screw drivers adapted to be in sorted in the chuck ofa brace or other rotary tool-holding device, but it is evident that the same mechanism may be provided with a permanent handle without departing from the spirit of the invention.

The main object is to provide the driver with movable gripping jaws capable of gripping the head of the screw to hold it in operative engagement with the turning V element or driver proper.

Another object is to provide the gripping jaws with means for counter-sinking the wood for receiving the head of the screw.

A still further object is to provide means for projecting the driver between and be yond the jaws and for. locking it in this position to permit the screw 'tobe set up tight with the surface ofits headbelowgor flush with that of the object to. which it is applied, and immediately following the counter-sinking of the wood bythe jaws.

ther objects and uses will bebrought out in the following description.

In the drawings Figure 1 is aside elevation of a screw driver embodying the various features of myinvention. Figs. 2. and3 are enlarged vertical sectional views of the same screw driver, taken at right anglesto each 7 other. Figs. 4 and 5 are enlarged transverse sectional views taken respectively on lines 4 l and 5-5, Fig. 1. Fig. 6 is a cross sectional view of the cutting edges of the jaws in the act of countersinking a body of wood to receive the head of a screw.

This screw driver comprises a head--1-- having its upper end provided with a reduced tapering shank or stem 2- adapted to be inserted in a suitable tool holder (not shown) and its lower end cylindrical and formed with diametrical lengthwise slots -3 and i at right angles to .each other for receiving and guiding respectively a screw-drivin g member 5- anda pair of jaw-supporting levers -'6-.

A tubular sheet or casing -7-, is screwed or otherwise secured to the cylindrical portion of the head -1- to cover the slots 4 and 5- and serve as a convenient handle by which the tool may be inserted into and removed from the chuck or other holding device (not shown) without interfering with the inclosed parts, the upper end of the tubular casing being abutted against an annular shoulder -8 on the head for a purpose hereinafter mentioned.

The main body or lower portion of the driving member 5 is fiat" and guided alongits edges in the slot -3 to cause it to turn with the head -l and at the same time to permit relative endwise movement of those parts, the upper end oi the driver constitutinga shank which is guided in a socket 9 centrally in the head and of su'l'licient length to allow a limited relative endwise movement of the head and driver as will be hereinafter more fully explained.

The levers --(3" are movable longitudinally and radially in the slots 4 at opposite sides oi the driver 5 and extend some distance below the lower end ofthe.

head -1 and easing 7--, their lower ends being provided with opposed gripping jaws -ll for holding a screw (as a,) in operative engagement with the driver and are also provided with cutting blades -.-12 for producing a counter bore or socket 5 in a wood body as B into which the screw is inserted, thereby allowing the head of the screw to be countersunk and also permitting the insertion of a wood plug to cover the head of the screw it de sired, Y

The radial or opening and closing movement of the aws from and upon the head of the screw is produced simultaneously with their longitudinal movement by forming the intermediate portions of the levers with oppositely inclined slots 13 converging inwardly and receiving suitable studs or screws 14l in the lower end of the head whereby as the levers drop by their own weight to the limit of their downward movement as determined by the upper ends of the slots 13, the jaws will be forced apart or when moved in the opposite direction or inwardly bv hand, as for example when engaging the jaws with the head of the screw, said jaws will approach each otherand firmly engage and hold the screw, the levers 6-- being additionally guided in their vertical movement against lateral displacement by pins 15 also on the lower end of the head 1 within the casing ---7.

' The upper ends of the levers 6 are pivotally connected to toggle arms 16 which in turn enter a lengthwise slot 17 in the shank of the driver 5 and are pivotally connected by a pin -18--- so as to allow a limited endwise and radialmovement of the levers and toggle arms, the pin -l8 being guided in a lengthwise slot 19 in the shank of the driver for a purpose presently described.

The length of the slots in the shank of the driver 5 is somewhat greater than those in the levers 6- so as to allow the lever-fend of the device to extend between the jaws and some distance below the cutters when the levers and jaws are in their lowermost positionsas determined by the engagement of the upper ends of the slots -13- with the pins 1 l, the driver being adapted to be locked in this extreme down position by means of a locking bolt -20 engaging a shoulder 21 on the driver 5 to permit the screw to beset up tightly with its head flushiwith or below the surface of the wood without countersinking such wood or after the countersink or bore b has been cut. Thi locking bolt is slidable in a radial guide opening 22 in the lower bolt and the adjacent side of the case 7, the

opposite end of the bolt having a removable cap or button i25- screwed thereon and eXposed through an aperture -26 in the case so that the bolt may be forced from its locking position by the finger of the operator to release the driver and allow it to be moved upwardly. Now, assuming that the levers and aws are in their extreme down positions and that it is desired to insert the screw into the wood and to cut the bore b, then the head of the screw in one hand is placed against the lower end of the driver with its slot registered therewith and by pushing up on the screw, thereby elevating the driver -5 causes the lower end of the slot -19 in the shank of the driver to engage and lift the pin 18 thus rocking the adjacent ends of the toggle arms l6 upwardly and when the head of the screw is between the jaws, the latter may also be grasped between the fingers and raised with the driver until such jaws tightly grip the screw-head, the jaws and screw beinglheld in this relation by hand until thepoint of the screw is restedagainst the object into which it is to be inserted.

Now, as pressure is applied to the head in the direction of drive of the screw, the engagement of the pins -1 l in the slots l3 causes the jaws to grip more tightly the head of the screw while the same pressure is applied to the driver through the engagement of the pin -18 against the lower end of the slot 19, thus permitting the screw to be turned or screwed into the wood until the cutters 12 have cut the socket b, it being understood that when the jaws grip the screw-head under downward pressure on the head 1, the levers and jaws become locked to said head and thus hold the pin 18- against the lower end of the slot -19 to prevent slipping of the driver from the head of the screw. As soon as the bore bis cut to the proper depth and before the screw is finally set up, the rotation of the driver is reversed to partially withdraw the screw sufiicient to withdraw the knives 12- from the socket .7) whereupon the head 1 may be further lifted leaving the driver to rest by its own weight in the slot of the screw until the cutters are clear from the surface ofthe wood and the bolt 20 is interlocked with the shoulder 21 on the rod whereupon downward pressure and rotary motion may again be applied to the driver 5 to drive the screw to its final position with its head in the socket or bore -b after which the entire tool may be withdrawn ready for a repetition of the operation described.

What I claim is:

l. A. screw driver comprising a head slotted lengthwise in planes at right angles to, each other, a driving member movable lengthwise 0f the head and guided in one of said slots to rotate with the head, a pair of screw-gripping jaws movable lengthwise of the head and guided in the other slot to also turn with the head, said jaws and head being provided with cotiperative devices including inclined ways, and members engaged therewith for forcing the jaws into gripping engagement with the screw as the head is moved toward the work relatively to the jaws.

2. A screw driver comprising a head, a pair of screw-gripping jaws movable lengthwise of and upon the head, said jaws and head being provided with cooperative devices including inclined ways and members engaged therewith for forcing the jaws into gripping engagement with the screw as the head is moved toward the work relatively to said jaws, a driving member movable lengthwise of and within the head and provided with a stop shoulder, and a locking bolt having a guide opening therethrough through which the driving member is slidable, said guide bolt being spring-pressed in one direction and provided with a lock ing shoulder for interlocking engagement with the locking shoulder on the driving member to hold the latter against inward movement when drawn outwardly to project its screw-engaging end a predetermined distance beyond the gripping portions of the jaws.

3. A screw driver comprising a head, a driving member adapted to engage a slot in a screw, said driving member being longitudinally movable in the head and guided therein to turn therewith, opposed jaws mounted on the head for engaging opposite sides of the head ofthe screw to hold said screw in operative engagement with the driving member, said jaws being provided with inclined slots converging upwardly, and pins on the head riding in said slots for forcing the jaws into engagement with the screw as the head is pressed toward the object in which the screw is inserted.

and connections between the inner ends of the lever and screw-driving member for rocking the levers upon their fulcrums to cause the jaws to. grip the screw when the driving member is engaged with said screw and the head is moved toward the work relatively to the jaws.

In witness whereof I have hereunto set my hand this 30th .day of January 1914:.

JOSEPH H. TOBIN. Witnesses:

H. E. CHAsE, EVA E. GREENLEAF.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). G.

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