US2363215A - Holder for boring bars - Google Patents

Description

Nov. 21, 1944.

L. L. WILLIAMS HOLDER FOR BORING BARS Filed Dec. 18, 1942 A it being understood that bars of different sizes such as used in connection with lathes. v l l It frequently happens that holes of difierent Es PATENT orries j Y"2f,363,2l5 j" sandman Boimvcr BARS H i y ft iiieen.'w i sfri a u.fi e-..

pui m aeata 1s, ie izkseriai uo.b 9391 *Th'is invention relatesjtb aholder desigried prl i marilyjior rigidly gripping'and supporting boring mental lugs-B proportioned to fit snugly within the upperportionpfithe slot B when the iofajse is properly'supported on the rest A.

sizes must be formed in one piece of work and in order that bars of different sizes may be placed in position as needed and tightly gripped so as to prevent vibratiomthe present invention has been devised. i

A further object is to providea holder which is simple and compact in construction and can be readily assembled. I.

A further objectis to provide a holder capable of tightly gripping boring bars of different diam- The upper edge of the base I has regularly spaced lugs 9 extending upwardly therefrom and preferably rectangular. These lugs are adapted to fit snugly within correspondingly shaped and proportioned notches or recesses l 0 formed in the l lower edge of a lower clamping member I I. This eters holding them firmly against vibration and rotation.

With the foregoing and other objects in view which will appear asthe description proceeds, the

ginvention consists ofycertain novel details of construction and combinations of parts hereinafter more fully described andpointed out in the claim,

changes may be made in the construction and arrangement of parts without departingfrom the spirit of the invention as In the accompanying drawing the preferred form of the invention has been shown.

In said drawing: I Figure 1 is an elevation of the holder and a portion of the compound rest onwhich it is mounted,

a boring bar being shownin section.

Figure 2 is a section online 2-2, Figure 1, a

portion of the boring bar .tion. it

Figure 3 is a section on line 3-3, Figure 1. Figure .4 is a bottom plan view of the holder. Referring to the figures by characters of reference, A designates the usual compound rest of a lathe provided with a slot B such as commonly being shown in elevaemployed and the walls'ofw "ch are shaped to overhang and frictionally engage an insertible key I ed stem 2 projecting upwardly therefrom and out of the slot B. I

A cylindrical core. 3 has a screw-threaded bore 4 extending 'intooneend for engagement by the stem .2. while extending from the other end of the core is a screw-threaded stem 5. The bore i 4 and stems 2 and 5 are co-axial with the longitudinal center of the core.

x The lower portion of the core is fitted snugly within a round opening 6 extending through the v center of a base member 1 which is preferably cylindrical. This base member has opposed segmember is fitted snugly upon the post 3 and cooperates with an upper clamping member I 2 which is also fitted snugly about the post 3, the

A cylindricalopening I 4 is extended diametrically through the post 3 and is sufficiently large to receive a boring bar 0 of the maximum size Formed in the upper to be held by thedevice. end of the member II and the lower end of the member I2 are matching recesses l5. These recesses cooperate to provide circular openings of different diameters any one of which can be brought into alinement with the opening M. A I6 engages stem 5 and by loosening this nut,

nut

theclamping member l2 can be lifted or]: of the post 3. .With the boring bar C out of position in the holder, the lower clamping member I I can be raised a sufficient distance to release it from the studs 9 and thereafter this lower clamping mem ber can be rotated to bring into alinement with i i the opening 14 the recesses l5 of proper size to receive a boring bar of the size to be used. After this angular adjustment of the lowerwclamping provided at its center with a screw-threadmember II has been effected, the boring bar of the selected size is inserted into theopening I 4 and the selected recesses IS. The upper clamping member I2 is then lowered into position on the bar after being adjusted to bring a recess l5 of correctsizeinto position to match each of the selected recesses l5 in the lower clamping member ll. Nut l6 isnext tightened and this will cause the upper and lower clamping members to bind tightly upon the inserted boring bar and at the same time pull thekey I upwardly so that the compound rest will be tightly gripped between this key and the lower portion of the base 1. Thus the boring bar will beheld rigidly in a parts II and I2 selected position When it is desired to change toa boring bar of and will notturn or vibrate.

another size to be used on the same job, all that is necessary isto unscrewthe; nut I6, lift the so that they are free to turn to lower these member after an opening of theselected size has been brought,

on post 3 and then into register with the opening I4. The boring bar of the selected size is then inserted and the parts again tightened as heretofore explained.

While this tool is designed primarily for hold- I ing boring bars as described, it can also be employed advantageously on jobs requiring outside turning and facing. I

Importance is attached to the fact that the parts can be assembled readily and that the adjustment can be effected rigidly. Itis also important to note that any boring bar within certain limits of size, will be gripped firmly by the holder and thus held against vibration while turning.

What is claimed is:

In a boring bar holder for lathes, to be received and held against rotation in the a key shaped tation on the compound rest, upper and lower bar-clamping members rotatably and slidably mounted on the post, said members cooperating to provide regularly spaced openings therebe tween arranged in pairs, the openings of each pair being diametrically opposed and of a size differing from the openings of the other pairs, the pairs of openings between the clamping members being shaped to receive boring bars of different diameters, means carried by the post for moving the-upper clamping member toward the lower clamping member, to bind a boring bar in a selected pair of openings and cooperating, circum- A ferentially-arranged lugs and recesses on the lower clamping member and on the base, and

holding the upper clamping member against ro- 'tation with respect to the lower clamping memslot of the compound rest of a lathe, a threaded stem on the key, a post threaded'on the stem and having a diametrical opening for the reception of a boring bar, a base slidably and rotatably mounted on the post, means on the basefor insertion into the slot, to hold, the base against roberg-said lugs and recesses, the key, and a bar which may be placed in a selected pair of openings, giving the upper clamping member an anchorage in the slot af lathe rest,- against rotation. 5 LORAINE L. W-ILLIAMS.

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