US2450582A - Spring type toolholder - Google Patents

Description

SPRING IYPE TOOLHOLDER Filed April 20, 4 1945 INYENTOR. 86

Patented Oct. 5, 1948 2,450,582 *y SPRING TYPE 'rooLHoLDER Lyof Martin Coyle, Babakin, Western Australia, Australiav Application April Z0, 1945, Serial. No. 589,351 In Australia December 10, 1943 Section l, Public Law 690, August 8, 1946. Patent expires December 10, 1963 This invention relates to improvements in spring type tool holders.

Although spring tool holders are comparatively effective for cutting-off, slotting, finishing, screwcutting and the like, yet they are capable of considerable improvement, particularly in respect of cutting off.

f These spring tool holders normallyfhave the springing action due to a slot in the holder between the main body :and the head in which the cutting tool is held. In one of these known types of tool holders the slot commences at the bottom edge of the holder, then runs approximately straight up, and is then curved in involute form to above and past the centre line of the opening in the head in which the tool is held. The springing is controlled by a longitudinal bolt connecting the sprung head to the body and capable of being tensionally adjusted by a nut.

In the tool holders of this type there has been a lack of lateral stability. That is to say, there has been a tendency for the head to spring sideways. Moreover, the means employed for holding the cutters have been` such that if digging occurs, the result must be either severe strain or tool breakage, because the tool cannot free itself. In addition, there has been no possibility of substantially altering the height of the cutting edge.

The tool holder comprising this invention overcomes the foregoing disadvantages.

It consists of a holder in which the cutter is held in separate frictionally held mountings, and these -mountings have an extension that contracts a Xed partl of the holder, thereby increasing lateral stability. Moreover, the height of the cutting edge oi the cutter can readily be altered due to the mounting supporting it being frictionally held and therefore adjustable in the head.

Further, the tool holder will accommodate various mountings adapted to take a Variety of shapes and sizes of cutters in either the right or left-hand position.

The invention will vreadily be understood by reference to the accompanying drawings. In these- Figure 1 is a side elevation of the tool holder in which the ttings for holding the cutter have been omitted:

Fig. 2 is a modified form oi tool holder such as may be used when it is desired to have a low,

centered tool:

Fig. 3 is a front elevation of a side cheek being part of the means for holding the cutter:

4 claims. (c1. 25J-91.5)

2 Fig. l is a similar view of a holding bolt used in conjunction with the cheek illustrated in the previous iigure:

Fig. 5 is a side elevation of the cheek illustrated in Fig. 3:

Fig. 6 is a front elevation of a modiiied iorm 1 of cheek for holding the cutter used, and

Fig. 'l is a front elevation ofanother modification for holding the cutter. y

As shown in the drawings, the tool holder Ill roughly conforms to conventional proportions though the head end is somewhat deeper than is usual. There is acurved slot or cut li whichk commences near the front of the working end of thetool and extends in somewhat semi-circular form to the top past the centre line of where the tool mountings are supported. Therefore the head lies closely yoked within the two prongs l2 yand I3 of the holder` body. A longitudinal bolt M passes through the tool so that, by anadjusting nut I5 spring tension may be varied to diierent requirements, for example to take up chatter and to act as a stabiliser so that the head will not become dislodged through shock of rebound or heavy spannering. The cutter is not mounted directly in the tool holder butin separate detachable and interchangeable mountings.

To accommodate these components or mountings,

the sprung head of the tool holder, which is in vertical alignment with the unsprung prongs, is provided with an opening It transversely through it.

One iormof mounting adapted `to take or hold the cutter is that illustrated in Figs. 3, 4 and 5.

. This comprises a side cheek I1 that has a shank I8 passing through the opening I5 in the holder and has a nut I9 screwing on the end of the shank and adapted to engage against the far side of the head of the holder. Through the cheek and the shank there is an opening that` accommodates a holding bolt 26 having an enlarged and cut-away countersunk head 2i and a nut 22 screwed on to the shank at the far side against the shank i8. The cutter is held in the recess 23 formed in the cheek I1 by the pressure of the countersunk head 2| of the holding bolt 20.

A further form of mounting for holding the cutter is that illustrated in Fig. 6. This also has the side cheek I1, shank I8 and bolt i9. It, however, has a square or rectangular opening Z4 in the cheek and the cutter is held in position by means of a set screw 25 passing into the cheek downwards from the top.

A still further mounting is that illustrated in Fig. 7. In this form, the cheek l1 is provided with 3 an opening through which passes a wedge-type head 27 with a holding bolt 26 held in position by the nut I9 screwed on in the usual way.

It will be noted that in each case the cutter mountings are made frictionally to engage the sprung head l l to the required extent, whilst the lower portion of the side cheek I1 contacts the lower unsprung prong I3 of the body so as to prevent lateral deflection. As a result cf the way it is mounted, the cutter can free itself without breakage in the case of digging in or seizure through choking. It is also readily adjustable for height without disturbing the holder.

The modified form of holder illustrated in Fig. 2 is a form that will be suitable when it is desired to have -a low centred tool. In this case, the opening |6 can be made lower because there is no head of the bolt i4 to be fouled. In this case, an inset 28 is tapped to act as a nut for the bolt I 4. In this and other forms of the invention also there may be a slot 29 at the far end of the holder so as to give additional resiliency in the vicinity of the nut l5.

I claim:

1. A tool holder of the spring type comprising in combination a head portion formed therewith and having an opening therein, said holder having a curved slot formed therein that commences near the forward end of said head portion and extending in substantially a semi-circular forni to above and forward of the opening formed therein whereby said head portion will be resiliently connected to said holder, a mounting extending through the opening Within said head portion and frictionally held to the latter, a cheek for holding the cutting tool forming a part of said mounting and extended so as to engage against a iixed part of said holder as Well as said resiliently connected head portion and means for holding the cutting tool in said frictionally held mounting.

2. A tool holder of thespring type comprising in combination a head portion formed therewith and having an opening therein, said holder having a curved slot formed therein that commences near the forward end of said head portion and extending in substantially a semi-circular form to above and forward of the opening formed therein whereby said head portion will be resiliently connected to. said holder, a mounting, a shank formed with said mounting and extending through the opening within said head portion, a

nut engaging said shank for frictionally retaining said mounting to said head portion, a cheek forming part of said mounting and extended so as to engage against a iixed part of said holder as well as against said resiliently connected head portion and means for holding a cutting tool within said frictionally held mounting,

3. A tool holder of the spring type comprising in combination a head portion formed therewith and having an opening therein, said holder having a curved slot formed therein that commences near the forward end of said head portion and extending in substantially a semi-circular form to above and forward of the opening formed therein whereby said head portion will be resiliently connected to said holder, a mounting, a shank extending through the opening within said head portion, means engageable with said shank for frictionally retaining said mounting upon said head portion, a cheek formed with said mounting, a threaded shank connected to said cheek and extending through said shank formed with said mounting, a nut engageable with said threaded shank for frictionally holding said cheek upon said mounting and an enlarged and countersunk head formed with said threaded shank for retaining the cutter tool in position within said cheek. si. A tool holder of the spring type comprising in combination a head portion formed therewith and having an opening therein, said holder having a curved slot formed therein that commences near the forward end of said head portion and extending in substantially a semi-circular form io above and forward of the opening formed therein whereby said head portion will be resilientiy connected to said holder, a mounting, a holiow shank formed with said mounting and extending through the opening within said head portion, means engageable With said hollow shank for frictionally retaining said mounting upon said head portion,'a cheek forming a part of said mounting, said cheek having extending portions engageable with said` holder and head portion, a bolt extending through said cheek and hollow shank of said mounting, a Wedge-shaped head formed with said bolt and means engageable with said bolt for frictionally retaining said cheek into engagement with said head portion as well as retaining the cutting tool within said cheek.

LYOF MARTIN COYLE.

REFERENCES CITED The following references are of record in the ile of this patent:

UNITED STATES PATENTS Number Name Date 801,256 Moore Oct. l0, 1905 872,760 Schulz Dec, 3, 1907 932,576 Ramsey Aug 31, 1909 1,214,225` Schillberg June 30, 1917 1,416,832 Johansson May 23, 1922 1,422,491 Stahl July 11, 1922 FOREIGN PATENTS Number Country Date 524,930 France Sept. 13, 1921

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