US812198A - Bit-brace. - Google Patents

Description

a n w n 1.. H lr s s 1... T Rw m E H P s 2 D E T N E T A P 4. o 9 l 7. 2 ...GM TEU RCA mmm s L MHH .1w JBH A c I L D.. P A oo. 9 l 2 l 8 0.. N

PATENTED FEB. 13, 1906.

J. GBSSERT.

BIT BRAOB.

APPLIOATION HLBD AUG.27,1904.

2 SHEETS-SHEET 2.

lNED STATES PATENT OFFICE.

Specification of Letters Patent.

Patented Feb. 13, 1906.

Application filed August 27, 1904. Serial No. 222,426.

To all whom it may concern:

Be it known that I, JACOB GEssERT, a citi- .zen of the United States, residing at Buffalo, in the county of Erie and State of New York, have invented certain new and useful Improvements in Bit-Braces, of which the following is a specication.

This invention relates to improvements in bit-braces; and its primary object is to provide a brace which can be used in very small quarters, such as are inaccessible to ordinary braces, it being particularly designed for cabinet-work, which often requires boring to be done in pigeonholes of desks and other similar places ordinarily inaccessible to a bitbrace.

Other objects are to provide a bit brace wherein the actuation of the same is caused by a pull and thrust action on the operatinglever or handle, by means of which actionthe head of the brace carrying the bit can be inserted into a small space and the handle actuated from without such space; to so construct the brace that it may be actuated by an oscillating movement of the handle; to provide a pressure device independent of the handle, which permits the head of the brace to be inserted into a small space and whereby suflicient pressure may be exerted on the head to cause the bit to bite or take hold; to provide braking means whereby the chuck or stock is held against retrograde movement during the initial action of the brace, or, in other words, until the bit enters the wood sufliciently to cause enough friction to prevent retrograde movement of the bit, and to otherwise improve bit-braces.

To these ends the invention consists in the construction, arrangement, and combination of parts to be hereinafter described, and particularly pointed out in the appended claims.

In the drawings, Figure 1 is a perspective view of my improved bit-brace, the handle being shown for operation by a thrust and pull action. Fig. 2 is a top plan view of the same, the handle thereof being shown as used when swinging or oscillating through an arc of a circle. Fig. 3 is a longitudinal section, on an enlarged scale, taken on line 8 3, Fig. 2. Fig. 4 is a transverse section through the head of the handle and the stock, taken on line 4 4, Fig. 3. Fig. 5 is a horizontal section through the pressure-bar head and the shank of the stock, taken on line 5 5, Fig. 4. Fig. 6 is a horizontal section taken on line 6 6, Fig. 3. Fig. 7 is a longitudinal section taken on line 7 7, Fig. .2. Fig. Sis a horizontalsection taken on line S S, Fig. 7. Fig. 9 is an enlarged detached perspective view of one of the camdisks whereby the actuating-pawls are disengaged from the ratchet.

Referring to the drawings in detail, like letters of reference refer to like parts in the several figures.

The handle comprises a radial bifurcated head A and a pivoted holding portion O. The bifurcated head has its outer end closed by a wall, as at a, and is provided with a cylindrical shank B, having its outer end fiattened on one side to form substanti ally a semicylindrical extension b. The holding portion C of the handle is preferably cylindrical with a portion of its length of corresponding diameter to the shank B. The inner end of said holding portion is pivotally attached to said shank and provided with a complementary fiattened extremity through which and the flattened end of the shank a pivot-pin c is passed, thus permitting the holding portion of the handle to be swung at an angle to said shank for operating the brace by a thrust-andpull action. A sleeve D surrounds the handle and is movable longitudinally thereon, its function being to lock the holding portion of the handle rigidly to the head A when swung in line therewith, so as to allow the operation of the brace by a swinging movement of the handle through an arc of a circle. At such times the sleeve is moved against the head to completely surround the shank and the complementary flattened portions of the same and the handle.

Within the bifurcated head A is located a ratchet-wheel E, and passing through the latter and registering openings in the arms of the said head is the shank f of a stock or chuck F. Said ratchet-wheel is secured to said shank by a pinf to cause the latter to revolve therewith. The stock may be of any desired type; but for the perfect and free working of other parts to be hereinafter described the saine is preferably cylindrical.

Located between the two arms of the bifurcated head in the intervening space separating the ratchet-wheel E from the rear wall a of said head are two ratchet-pawls G, pivotally attached by pivot-pins g, passing therethrough between the ends thereof and through the arms of the head. Each pawl has asocket or depression g formed inits opposing face on that side of the pivot-pin near the rear wall of the head, and interposed between the pawls IOO IIO

with the ends thereof seated in said sockets is an expansion-spring H, serving to separate the free ends of the pawls, and consequently force the acting ends thereof into engagement with the ratchet-wheel.

Owing to the arran ement of the various parts, the brace woul b'e rendered undesirable by the en agement of both pawls with the ratchet, it being constructed, primarily, as a ratchet brace. I therefore provide means for disengaging either one of said pawls from the ratchet, which 'comprises two camdisks I, located at opposite ends of the rear wall of the ratchethead and revolubly secured thereto by a pivot pin J, passing through said wall. Acting cam-faces are formed by gradually diminishing the thickness of each disk from a point k to a point 7c', thus formin inclined cam-faces around central bosses 2. The cam-face of each disk lies in operative proximity to the, inner ends of the pawls G, and upon revolving said disks the gradually'- inclined surfaces cause the pawls to be disengaged from the ratchet. The said disks are loosely mounted on the pivot-pin J for independent rotation.

It is apparent from the foregoing that the brace may be operated by an oscillating movement of the handle through an arc of a circle, which is desirable in open places where space will permit of such movement, as increased leverage can be obtained, or by a pulland-thrust movement of the handle when only the short shank of the head is moved through an arc of a circle.

As it is always necessary that pressure be exerted on the bit, I provide a pressure-bar L, which is advisedly positioned in line with the chuck or stock for a purpose to appear hereinafter, it having at itsinner end an upwardly and inwardlv extending arm Z, which terminates in a head l', having a depression or socket Z2, opening inward, into which latter the upper end of the stock-shank f fits. The latter is provided with a circumferential groove M, into which flat keys m fit, which pass through lateral openings `m in the head of the pressure-bar and whose inner ends are curved tocorrespond to the reduced portion of the shank formed by said groove. To prevent accidental displacement of said keys from the groove in the shank, suitable screws N are screwed into openings f/L in the head of the pressure bar and pass through perforations 11, in said keys. By this arrangement the ressure bar is locked securely to the chuc and is free to turn on the shank thereof, while allowing the chuck to turn without turning said head. The pressure-bar is made hollow and is open at its outer end and provided with slots O at diametral points. A stop-bushing P is secured in said bar near its outer end by a pin p, passing through the same and entering said bushing. The latter is provided with a longitudinal opening p',

through which and a perforation pi in the inner closed end of the bar a brake rod R is passed, which extends from opposite ends of said rod. The inner end of said brake-rod has afhxed thereon a brake-shoe R', adapted for engagement with the stock or chuck,while the outer end of said rod is threaded to receive an adjustin -nut S, which partly enters the open end o the pressure-bar. Apin T is passed through the brake-rod and has its ends extendinginto the slots O in said pressurebar, which prevents turning of the brake-rod, while serving as a convenient guide. Surrounding said brake-rod with its ends bearing a ainst the pin T and the inner end of the stopushin P is a spiral spring U, which serves to hoId the brake-shoe with the necessary pressure against the chuck or stock of the brace.

In operating the device the adjusting-nut S is turned to allow the spring U to force the brake-shoe against the chuck. The sleeve D is then moved along the handle to permit the same to be swung at a right an le or at any other angle to the shank of the ead A, or if at an angle to said shank and `it is desired to use the same in rigid form the handle is swung in line with said shank and the sleeve moved inward along the handle to surround both the said shank and the inner end of the handle. The ressure-bar is then taken hold of and the too placed a ainst the work. The handle is actuated in eit er manner described as may be necessary or desirable, and after the bit has entered the work and is held sufflciently by friction to prevent retrograde movement the adjusting-nut is screwed farther .onto the brake-rod, which causes the brake-shoe to be drawn away from the stock or chuck. After the desired depth is bored the cam-disks are both revolved to disengage the acting pawl from the ratchet-wheel and engage the idle pawl therewith, which causes a reversal and the withdrawal of the bit. It is therefore apparent that the brake-shoe is put into service only when starting to bore, and as soon as reverse movement of the bit is unlikely it is withdrawn from the chuck. This is a very essential feature when the brace is used in small quarters, which requires pressure to be exerted on the brace from without such quarters.

While the construction shown and described is the preferred one, I do not wish to limit myself to such construction, as many changes may be resorted to without departinoV from the scope of my invention or sacriiiclng any of the advantages thereof.

I-Iaving thus described my invention, what I claim is- Y 1. A bit-brace comprising in combination, a pressure-bar and a stock mounted to rotate therein and be governed thereby, said stock having a ratchet-wheel ri id therewith, a handle having a head rotata le on said stock IOO IIO

and carrying a pawl engaging said ratchet- Wheel, and a braking device carried by said pressure-bar engaging said stock and resisting rotation on the return of the pawl.

2. A bit-brace comprising in combination, a hollow pressure-bar having an offset arm, a stock mounted to rotate in said arm and having a ratchet-wheel rigid thereon, a handle rotatable on said stock and carrying a pawl engaging said ratchet-wheel, and a braking device comprising a brake-shoe and a rod mounted in said pressure-bar.

3. A bit-brace comprising in combination, a hollow pressure-bar having an offset arm, a stock mounted to rotate in said arm and having a ratchet-wheel rigid thereon, a handle rotatable on said stock and carrying a pawl engaging said ratchet-wheel, and a braking device comprising a brake-shoe, a rod carrying said brake-shoe mounted in the pressurebar7 a spring tending to force said rod inward to hold said brake-shoe against the stock, and means for drawing said rod outward against the action of said spring.

4. A bit-brace comprising in combination7 a hollow pressure-bar having. an offset arm and longitudinal slots at diametrically opposite points, a stock mounted to rotate in said offset arm and having a ratchet-wheel rigid thereon, a handle rotatable on said stock and carrying a pawl engaging said ratchet-wheel, and a braking device comprising arod mounted in said pressure-bar' and having its ends projecting therefrom and its outer end threaded, a brake-shoe at the inner end of said rod, an adjusting-nut fitting onto the threaded end of said rod, a pin passing through said rod and guided in the slots in the pressurebar, a stop-bushing held in said pressure-bar, and spiral s rings surrounding said bar and bearing wit its ends against said pin and bushing, respectively.

5. A bit-brace comprising in combination7 a pressure-bar and a stock mounted to rotate therein and be governed thereby, said stock having a ratchet-wheel rigid therewith, an operating-handle carrying a pawl engaging said ratchet-wheel and having a head rotatable on said stock provided with a radial shank, and a holding portion pivoted to said shank and capable of being swung at an angle to or in line with said shank, means for locking the handle and shank rigid when y alined, and a braking device carried by said pressure-bar engaging said stock and resisting rotation on the return ofthe pawl. :u

In testimony whereof I'have afliXed my signature in the presence of two subscribing witnesses.

JACOB GESSERT.

Witnesses EMIL NEUHART, EDWIN MAIER.

Images