US1212481A - Bit-brace. - Google Patents

Description

S. N. HALL.

BIT BRACE.

APPLICATION FILED JULY 15. 1915.

Patented Jan. 16, 1917.

2 SHEETS-SHEET I.

Attorneys S. N. HALL.

BIT BRACE.

APPLICATION FILED JULY 15, I915.

Patented Jan. 16, 1917.

2 SHEETS-SHEET 2.

Inventor Witnesses Attorneys .wAsHINO 101mm. c

EPAN FFTQ.

SAMUEL N". HALL, OF MEMPHIS, TENNESSEE.

BIT-BRACE.

Specification of Letters Patent.

Patented Jan. 16, 1917.

Application filed July 15, 1915. Serial No. 40,053.

To all whom it may concern Be it known that I, SAMUEL N. HALL, a citizen of the United States, residing at Memphis, in the county of Shelby and State of Tennessee, have invented a new and useful Bit-Brace, of which the following is a specification.

This invention relates to bit braces of that type capable of rotating the bit chuck at one or more speeds relative to the speed of rotation of the yoke of the tool.

One of the objects of the invention is to provide a tool 'of this character having a novel arrangement of gears compactly arranged whereby the chuck can be rotated at two different speeds relative to the yoke, the shifting of the parts to get these different speeds being readily effected without requiring the use of any intricate mechanism.

A further object is to provide a bit brace utilizing a supplemental crank arm by the use of which the speed multiplying gearing can be operated, thisv supplemental crank arm being entirely removable when desired so as not to interfere with the use of the brace in the ordinary way or, in other words, in the manner of an ordinary one piece brace.

A further object is to provide simple and efficient means for housing and holding together the speed multiplying gears, it being possible readily to open the housing to remove the gears for the purpose of cleaning or repairing the same.

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed, can be made within the scope of what is claimed, without departing from the spirit of the invention.

In the accompanying drawings the pre ferred forms of the invention have been shown.

In said drawings :Figure 1 is a view partly in elevation and partly in vertical section of a bit brace embodying the present improvements, the chuck being broken aw y. Fig. 2 is an elevation of the speed multiplying gears and the shifting means, the adjacent parts being shown in section. Fig. 3 is atop plan view of the gear case and adjacent parts. Fig. 4: is a plan view of the gear case with the block removed. Fig. 5 is a section on line CD Fig. 1. Fig. 6 is a section on line EF Fig. 2. Fig. 7 is an elevation of one of the pawls. Fig. 8 is a vertical section through the gear case and speed multiplying gears of a slightly modified structure. Fig. 9 is a section on line GH Fig. 8. Fig. 10 is a view similar to Fig. 8 and showing another modified structure.

Referring to the figures by characters of reference 1 designates a yoke of the usual form, the same being provided with a knob 2 at its upper end and with an intermediate grip 3. The other end of the yoke is fixedly connected to and extends radially from a gear case l which is preferably substantially elliptical and is likewise preferably open at the bottom. The bottom of the gear case is adapted to be closed by a plate 5 having a marginal groove 6 designed to receive the lower edge of the wall of case f so that when the plate 5 is fitted snugly against and within the bottom portion of the gear case, it will be held against lateral displacement relative thereto. For the purpose of holding this plate 5 securely to the gear case, a bolt 7 is extended through the case and has a threaded end portion engaging the top of thecase. By having the bottom plate fitted against the case in the manner hereinbefore pointed out, it becomes necessary to use but the single bolt 7 for the purpose of fastening the plate 5 securely to the case. This bolt can be provided with a head 8 having a kerf whereby it can be readily tightened or loosened by means of a screw driver.

Bolt 7 not only constitutes a means for fastening plate 5 to the case 4, but it also constitutes a bearing on which gears 9 and 10 are mounted to rotate, the gear 10 being preferably of greater diameter than the gear 9 and the two gears being secured together by means of pins 11 or the like so as to rotate as one body upon the bolt 7.

Projecting from the: plate 5 is a tubular extension 12 exteriorly screw threaded and having its lower end flared as shown at 13. This extension receives a sleeve 14 having spaced annular grooves 15 and 16. A nut 17 engages the threaded exterior of the entension 12 and is fitted snugly about the sleeve 14:, this nut having an interior shoulder 18 adapted to retain a locking ball 19 within the flared portion 13 of the extension 12. The parts are so proportioned that when the nut 1'? is loosened by adjusting its shoulder 18 downwardly away from extension 12, the ball 19 will be free to shift radiallyfrom sleeve 14 and thus permit the sleeve to be shifted longitudinally to bring either groove 15 or 16 to position within the flared por tion 13 of the extension 12. By then tightening the nut 17 on the extension the ball 19 will be thrust against the flared end of extension 12 and deflected into the adjacent groove 15 or 16, thus to hold sleeve 14 against longitudinal movement relative to extension 12.

Sleeve 14 has a chuck 20 adjacent the end thereof, there being preferably a ball bearing 21 between said chuck and the sleeve. A stem 22 rotates with the chuck and within sleeve 14 and plate 5, this stem extending loosely through superposed gears 23 and 24 which constantly mesh with the gears 10 and 9 respectively. Radial grooves 25 are formed in the meeting end portions of the two gears 23 and 24 and a radial locking pin or key 26 is extended through and beyond stem 22 and is constantly seated in the grooves 25 in one or the other of the two gears 23 and 24.

The drive gear 24 has a tubular extension 27 journaled within the top of the gear case 4 and keyed or otherwise secured to this extension is the hub portion 28 of a ratchet disk 29 bearing on the top of the gear case,

as shown particularly in Fig. 2. A block 30 is mounted for rotation upon the hub 28 and carries a spring pressed pawl 31 the head 32 of which has a depending pin 33 adapted to work within a recess 34 formed in the block and thus to hold the pawl against rotation. Then the pawl is thus held it is free to slip in one direction over a circular series of recesses 35 formed in the disk 29. WVhen it is desired to render the pawl 31 inactive it is merely necessary to lift the pawl so as to remove pin 33 from recess 34, and to then rotate the pawl so as to prevent the pin from reentering the recess. Thus the pin will hold the pawl disengaged from disk 29. Another pawl 36 similar to the pawl 31 is provided in the block 30 and is designed to engage the top of the gear case 4, thus to hold block 30 against rotation relative to the gear case. The recess 37 provided for this pawl 36 has been shown in Fig. 4.

Block 30 has an opening 38 extending therethrough for the reception of a crank arm 39 the grip portion 40 of which is extended upwardly so as to lie within the cir cle of movement of the grip 3. Crank arm 39 has a longitudinal series of recesses 41 any one of which is adapted to be engaged by a spring pressed locking pin 42 extended into one side of block 30. Thus it will be seen that the crank arm 39 can be adjusted radially of block 30 so as to bring the grip 40 any desired distance from the block.

As shown particularly in Fig. 2, the block 30 is preferably held upon the hub 28 by a washer 43 held in place by a screw 44 which extends into the upper end of the extension 27. The lower portion of this extension constitutes a guide for the upper end of the stem 22.

It will be understood of course that when the pawl 36 is in engagement with the case 4 the crank arm 39 can be removed from block 30 and the brace used in the same manner as an ordinary brace, this being due to the fact that the case 4 is thus locked to block 30 and said block 30 is connected by pawl 31 to the disk 29. Thus movement of gear 24 relative to case 4 is prevented and the rotation of the yoke 1 will result in corresponding movement of the chuck 20.

Should it be desired to rotate the chuck faster than would be possible with an ordinary brace, it would be necessary to replace the crank arm 39 and to disengage the pawl 36 from case 4. By shifting sleeve 14 and stem 22 downwardly the key 26 will become seated in grooves 25 in gear 23 so that the rotation of gear 24 will result in the trans mission of motion through said gear and the gears 9 and 10 to gear 23 which is locked to stem 22, thus rotating the chuck 20 at a much higher speed than the crank arm 39. By shifting stem 22 upwardly and holding it in such position in the manner hereinbefore pointed out, the pin or key 26 will be brought into engagement with gear 24, thus coupling said gear to the stem with the result that when crank arm 39 is rotated relative to yoke 1, the chuck will be rotated therewith.

Should it be desired to open the case 4 for the purpose of cleaning or repairing the contents thereof, it would merely be necessary to remove the bolt 7 whereupon plate 5 would become detached from the case and the gears and the stem 22 would thus become detached from each other.

It is to be understood of course that any suitable means, such as a radial pin 45 must be provided for holding the stem 22 and the sleeve 14 together during the longitudinal adjustment of the stem.

The construction shown in Figs. 8 and 9 differs from that of Figs. 1 to 7 merely in substituting a recessed gear 24 for gear 24, and mounting a gear 23, equivalent to gear 23, upon a sleeve 14 which is the equivalent of sleeve 14, to slide with the latter to engage or disengage clutch element pins 26 of gear 23 with pin sockets 25 of gear 24 The construction shown in Fig. 10 diflers from that of Figs. 1 to 7 in substituting for gear box 4, a box 4 sufficiently deep to accommodate three gears in axial alinement in the interposition of additional gears 10 and 23 between gears 9 and 10 and gears 23 and 24:, respectively, and by providing a keyway 25* through gear 28 into gears 23 and 24. In this structure shown in Fig. 10 the yoke 1 can be rotated while the gear case 4; is otherwise held.

What is claimed is 1. A bit brace including a gear case, an exteriorly threaded tubular extension connected thereto and having a flared end, a sleeve adjustable longitudinally within the extension and having spaced annular grooves, a locking ball within the flared end and adapted to be seated in one of the grooves, means adjustably engaging the extension for holding the ball in one of the grooves to lock the sleeve against longitudinal movement, a chuck carrying stem revoluble within and movable with the sleeve, speed multiplying gears within the case, means for rotating one of the gears, and means controlled by the longitudinal movement of the stem for coupling said stem to either of two gears thereby to drive the stem at either of two speeds.

2. A bit brace including a gear case, a chuck carrying stem therein, superposed gears on the stem, one of said gears constituting a drive gear, connected gears mounted for rotation in the case, one of said connected gears being constantly in mesh with the drive gear and the other one of said gears constituting means for transmitting motion to the other gear on the stem, means for shifting the stem to uncouple it from the last named gear thereon and couple it to the drive gear, a ratchet disk revoluble with the drive gear, a member revolubly mounted upon the disk, a crank arm connected to said member,-a pawl carried by the member for engagement with the ratchet disk, and means carried by said member for engaging Copies of this patent may be obtained for five cents each, by addressing the the gear case to hold the member against rotation relative to the case.

3. A bit brace including a gear case, a yoke connected to the case, a stem slidably and revolubly mounted in the case, a drive gear within the case and upon the stem, speed multiplying gearing within the case and cooperating with the drive gear, means for shifting the stem to rotate the same at either of two speeds from the drive gear through the speed multiplying gearing, means for locking the drive gear against rotation relative to the case thereby to provide a direct drive to the spindle from the drive gear, and means for rotating the said drive gear when unlocked.

4. A bit brace including a gear case, an exteriorly threaded tubular extension connected thereto, a sleeve adjustable longitudinally within the extension and having spaced annular grooves, a locking means carried by the tubular extension and adapted to be seated in one of the grooves, a mem- -ber adjustably engaging the extension for holding the locking means in one of the grooves to lock the sleeve against longitudinal movement, a chuck carrying stem revoluble within and movable with the sleeve, speed multiplying gears Within the case, means for rotating one of the gears, and means controlled by the longitudinal move ment of the stem for coupling said stem to either of two gears thereby to drive the stem at either of two speeds.

In testimony that I claim the foregoing as my own, I- have hereto aflixed my signature in the presence of two witnesses.

SAMUEL N. HALL.

Vitnesses:

IvY E. SIMPSON, PHILOMENA A. RooKELLi.

Commissioner of Patents,

Washington, D. 0.

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