US1428099A - Brace and bit therefor - Google Patents

Description

J. V! JANIN.

BRAGE AND BIT THEREFOR. APPucAfmN FILED Aum. I920,

1,428,099. 'latentedseptl 551922.

JOE-IN "V'. JANIN, OF SEATTLE, WASHINGTON.

BRACE AND BIT THEREFOR.

Application filed August 5, 1920. Serial No. 401,458.

To all whom it may concern.

Be it known that 1, JOHN V. JANIN, a citizen of the United States of vAmerica, and resident of the city of Seattle, in the county of King and State of Vashington, have invent-ed certain new and useful Improvements in Braces and Bits Therefor, of which the following is a specification.

My invention relates to chucks which are intended for such tools as braces of the kind commonly used by carpenters.-

The object of my invention is to produce a chuck for such a brace havingnnprove ments in its construction which will facilitate its operation and cheapen the cost of manufacture thereof, while at the same time making a strong, durable and reliable tool.

Further objects of my invention will be seen from a study of the following descrip tion and the accompanying drawings.

lily invention consists of the novel parts and combinations of parts which will be particularly defined in the claims.

In the accompanying drawings I have shown the construction of my chuck in its preferred form.

Figure 1 shows a brace, the chuck constituting my invention being shown in longitudinal section.

Figure 2 is a partial section and partial elevation of a detail of the chuck.

Figure 3 is a cross section taken upon the plane indicated by the line 83 of Figure 1.

The bit-holder or chuck has a base or central frame member, which hasa head 1, this being slotted len thwise upon an axial plane, leaving two fingers 10, which fingers have their outer surfaces threaded, as is clearly shown in Figures 1 and 2. This head has an integral tubular shank 11 which carries its part of two rotative bearings, which bearings, as illustrated, are ball bearings.

\Vithin the slot in the head 1 are placed two bit-clamping levers 2. These are pivoted close to their-inner ends, to swing about pivot centers which are located well outwardly from the main axis of the bit-holders. As illustrated, the inner ends of these levers are provided at their inner sides, with convex rounded surfaces 20, and the outer sides with correspondingly concave rounded surfaces 21, the two surfaces 20 and 21 being concentric, or arcs of circles struck from the same center, which center is the pivot center upon which they swing.

The two inner, convexly rounded surfaces 20, which are upon the inner side faces of the bit-clamping levers2, are in contact with each other. These inner ends of the levers are held against separating by means of a retaining ring 22, clamped between a shoul der 18 of the head 1 and a collar 12 threaded upon the shank 11, and which has its inner surface curved to fit the rounding surface 21 of the two clamping levers. In this manner a pivotal support is provided for the bit clamping levers 2, which has its pivot center well outward from the axis of the bit-holder.

On the inner face of each of the bit clamping levers 2, near to, but slightly removed from their inner ends, are formed bit-engaging and holding surfaces, or recesses 23. The levers are recessed at this point so as to engage with a suitably formed tip 30 of the bit 3. The shank of the bit 3 at its inner end is provided with a tip 30, which has flattened side surfaces, or surfaces of any suitable character which are not surfaces of rotation, and the recesses 23, in the inner end side faces of the bit-clamping levers 2, are shaped to lit the side surfaces of the tip of the bit.

Preferably, this tip section 30 has the outer or end portion thereof slightly thicker than its inward portion, so that when engaged by the forcing together of the levers 2 it will not only prevent the bit from turning, but will positively grip and hold it against relative movement lengthwise of the bit, so that an outward pull upon the brace, while it is holding the bit, will not cause the brace to pull off from or release the bit.

Screwing upon the outer surface of the head 1 is the clamping sleeve 4. This sleeve has an inner tapered or conical surface 40, which is adapted to engage the outer end of the bit-clamping levers 2 to force them together when the sleeve is screwed down upon the head. As the point where the levers 2 engage the bit to hold it is quite close to the pivot axes upon which they swing, and the outer ends ofthese levers are a considerable distance therefrom, the gripping action upon the bit is very powerful. The swinging ends of the levers 2 are well within the open end of the sleeve 4, to leave its bit-receiving opening of maximum width.

The hole in the outer end of the sleeve 4, through which the bit is inserted, must be made large enough to accommodate the maximum sizes of bit shanks suited for use in the brace. Many of the bits which it would be desired to use do not require so large a shank. As I desire to employ the outer end of this sleeve as a support for the bit, I prefer to supply the smaller sizes of bits, or those having smaller shanks, with projecting wings, as 31, which have their outer surfaces corresponding with the outer surface of a cylinder, which would snugly fit the hole in the sleeve. These are located at ust 'the right distance from the end of the bit shank so that when the shank is secured in place, these wings will lie in the opening at the outer end of the sleeve 4. These wings may be provided entirely outside of the normal circular outline of the shank, or they may be formed in any suitable manner.

The shank 11 may be suitably mounted in a casing 50 secured upon the brace frame 5, as in ball bearings 51 and 52, for instance. The shank is shown as secured in place by means of a bolt 15 threading therein. The exact manner of mounting and securing the chuck in place, and the manner of controlling the direction of its rotation, form no part of my present invention, and may be accomplished in any manner found suitable or desirable. I shall not, therefore, describe such parts, as they may be such as are ordinarily found in similar tools.

Between the inner end of the bolt 15 and the inner ends of the bit clamping levers 2 is placed a spring 16, which acts upon the inner ends of the bit-clamping levers 2 so as to separate their outer ends. As illustrated, this is done through the medium of a small follower 17, which is placed between the spring and the ends of the levers.

The means employed for securing and holding the bit has a powerful grip thereupon, due to the relative length of the parts of the clamping levers 2. The construction of these parts is also such as will grip and securely hold the bit against an outward pull. The tip 30 of the bit, which is en gaged by the levers 2, is some distance from the wings 31, at which point the shank of the bit is supported against lateral movement. In consequence, the bit is very securely held against lateral deflection.

While I have described the bit-holding chuck only in connection with a carpenters hand brace, it is evident that it may be employed with other similar tools, as, for instance, abreast drill.

What I claim as my invention is:

1. A bit holder for braces having two clamping levers pivoted at their inner ends 1,4.2s,oee

and provided upon their opposed faces adjacent their pivoted ends with fiat bit holding surfaces, and a sleeve embracing and ljustable lengthwise of said levers and having cam surfaces engageable with the ends of the clamping levers opposite to their pivots, said sleeve having at its outer end and spaced from said bit-holding surfaces of the clamping levers, surfaces adapted for sup porting engagement with the bits placed therein.

2. A bit holder for braces comprising a body axially slotted and externally threaded, bit clamping levers fitting within said slot with their inner ends provided both at their inner and outer sides with pivoting surfaces permitting said levers to swing in their holding slot, a fulcrum and retaining ring surrounding the slotted body and engaging the external pivoting surfaces of said clamping levers, a clamping sleeve screwing upon said body and having an internal inclined surface engaging the outer ends of the bit clamping levers to swing them towards the central axis of the holder.

A bit holder for braces comprising a body axially slotted and externally threaded, bit clamping levers fitting within said slot with their inner ends provided both at their inner and outer sides with outwardly concaved pivoting surfaces permitting said levers to swing in their holding slot, said levers having bit clamping recesses upon their inner faces spaced outward from their pivot ends, a fulcrum and retaining ring surrounding the slotted body and engaging the external pivoting surfaces of said clamping levers, a clamping sleeve screwing upon said body and having an internal inclined surace engaging the outer ends of the bit clamping levers to swing them towards the central axis of the holder.

l. In a bit holder for braces, two clamping levers having their inner ends connected to permit their outer ends to be separated or brought together, said levers being formed to grip between them a bit, and a sleeve embracing and adjustable lengthwise of said levers and having cam surfaces engageable with the outer ends of the clamping levers, said sleeve having at its outer end and spaced from the gripping portions of said levers, surfaces adapted for supporting engagement with the bits placed therein.

Signed at Seattle, King County, Washington, this 30th day of July, 1920.

JOHN V. JANIN.

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