US 2089166 A
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Description (OCR text may contain errors)
Augi- 1937- H. o. RElC-HHARDT 2,089,166
TOOL HOLDER Original Filed June 12, 1934 zxvExToR,
A d I I ATTORNEY Fatented Aug. 3, 1937 g UNETEE gTATEfi PATENT ()FFICE TOOL HOLDER Hugo o. Reichhardt, Highland Park, Mich.
Application June 12, 1934, Serial No. 730,286 Renewed November 21, 1936 2 Claims. (01. 279-30) The object of my invention is'to provide a tool applicant has experienced great difficulty in reholder of simple, durable and inexpensive conmoving rotary operated tools, such as drills, struction. reamers and the like which have been retained A further object of my invention is to provide in their socket by ball type retaining devices.
5 a tool holder especially suitable for detachably Invariably, the ball is used to prevent rotation securing tools, such as punches, dies, reamers or of the tool in its socket so that this rotating torque similar articles, in fixtures adapted to receive sets up enormous strains between the ball same. This device in general consists of a spring and the tool. This condition enlarges the face urged roller which is wedged between an inof the tool which coacts with the ball thereby clined track on the fixture and a cam face distorting the shank of the tool at this point. formed on the tool to thereby lock the tool into Consequently, when it is desired to remove the its fixture. The applicant is aware that in the tool great difiiculty is experienced in forcing the past many devices have been constructed to acdistorted portion of the shank outwardly through complish this purpose, some of which employed the undistorted portion of the retaining opening.
l5 spring urged balls and rollers in a manner some- The applicant overcomes this objectionable fea- 35 what similar to the applicants construction; ture; first, by the provision of a roller instead of however, in all of such devices, known to the a ball, which roller coacts with the tool along a applicant, certain objections were inherent which line contact instead of a point contact as prolimited the commercial application of the devices. duced by a ball; and secondly, the edges of the go The use of all former locking devices invariably tools cam face are beveled so as to allow room required hardened surfaces both on the tool and for expansion of the tool face without causing dis- 0 on the fixture, and inasmuch as the fixtures in tortion of the bearing portion of the shank. Conmany cases were constructed of relatively large sequently, even after long use tools secured in blocks of steel, capable of holding many tools, place by the applicants device may readily be 2.", these fixtures became very costly to manufacture. removed. This feature is of special importance It is ordinary shop practice to provide a tool in connection with production machinery as it holding fixture in which many punch-es, for exminimizes to a large extent the time the machine ample, are secured. These punches are freis tiedup for necessary sharpening or renewal quently spaced a considerable distance apart so of drills, reamers or the like, associated therewith;
that when it is required that the fixture be hard- With these and other objects in view, my in- 0 ened considerable extra expense is involved. The vention consists in the arrangement, constructool receiving openings must be ground to correct tion, and combination of the various parts comfor the warpage inevitable in the hardening procprising my improved device, as described in the ess and more expensive steel must also be used. specification, claimed in my claims and illus- The applicant overcomes these objections by trated in the accompanying drawing, in which: 5
providing a hardened steel removable insert which Figure 1 shows a vertical central sectional view is adapted to be fitted into a suitable recess in through a fixture and tool having my improved a fixture block. Consequently, the fixture may retaining device installed thereon.
be constructed of inexpensive soft steel which Figure 2 is a top view of the device shown in need not be hardened to thereby produce a very Figure 1, illustrating the desirable proportions satisfactory device at a very low cost. This feabetween the retaining device and the tool secured 40 ture is of special importance in connection with therein. relatively large fixture blocks which contain Figure 3 is a cross sectional view, taken on the several punches spaced a considerable distance line 33 of Figure 1.
apart, as are used to a large extent in punching Figure 4 is a sectional view, taken on the line 4 sheet metal stampings. Still further, in case of i4 of Figure 2. the failure of any one tool retaining device, the Figure 5 is an enlarged View of the tool shank, applicant may easily insert a new unit in his illustrating the cam face which is formed thereon. fixture block; whereas, with usual devices of this Figure 6 is a sectional View, taken on the line character, an entirely new block must be made. 6-6 of Figure 5, and 50 The second improvement made by the appli- Figure 7 is a perspective view, illustrating the cant comprises means for preventing distortion or removable insert used in this device. peening cf the punch shank due to the pressure Referring to the accompanying drawing, I have of the retaining ball so that the tool may be used the reference numeral It] to indicate a fixreadily removed when desired. In the past the ture block which may be of any desired shape or 40 by the springs I'I between the faces I4 and I9 size. This block is provided with an annular tool receiving bore I I which extends therethrough, in which bore the shank of a tool l2 extends. The tool I 2 may be either a punch, as shown, or a drill, reamer, end mill or similar device, my tool retainer preventing not only the unintentional Withdrawal of the tool but also preventing rotation of the tool in the fixture.
The retainer proper comprises a rectangularly shaped insert of hardened steel I3 having a groove I5 extending across one of its flat sides,the bottom of this groove being inclined twenty degrees from the vertical so as to extend substantially diagonally through the block. The bottom of the groove forms an inclined runway Id. The ends of the insert I3 are cylindrical in shape so as to be more conveniently inserted in the fixture I0. It will be apparent that to insert the block I3 in the fixture it it will be only necessary to drill two openings, spaced from each other, and to then mill out the metal between these two openings so as to form an elongated recess. This recess should intersect one side of the tool receiving opening II. It is desirable that the width of the groove I5 be somewhat wider than the diameter of the opening II so as to prevent removal of the wedging roller through the opening II. The insert I3 is assembled in the fixture block IE! with the shallow end of the groove at the bottom and a roller I6 is provided in the groove I5 upon the inclined runway I4, this roller being resiliently urged downwardly by means of a pair of compression springs I! which are retained in position in the groove by means of a plate I8 which is secured over the top end or" the groove.
The shank of the tool I2 is provided with an inclined face I9, the angle of this face being approximately ten degrees from the axis of the shank. Consequently, the roller I6 will be wedged to retain the tool shank in the opening I I.
It will be noted that the two side edges of the face I9 are beveled at 20, the purpose of which is to prevent distortion of the cylindrical part of the shank because of the pressure caused by the roller I6.
In order to assemble the device, the unit, as shown in Figure 7, which includes the insert I3, roller I6, springs I! and plate I8, is inserted into the elongated opening in the fixture I0. Due to the elongated opening intersecting one side of the opening I I,the roller IE will partially obstruct this opening. If now it is desired to insert a tool, the shank I2 is simply pushed up into the opening II thereby compressing the spring II. As soon as the face I9 becomes aligned with the roller, the latter will be forced into wedging engagement between the faces I9 and I 4 and thus prevent the removal of the tool shank. A backing plate 2| is provided which resists the downward thrust of the tool so that the roller I6 solely prevents the removal of this tool.
When it is desired to remove the tool from the fixture a key, as shown by dotted lines 22, is inserted upwardly through an opening 23 formed in the fixture II] which tool moves the roller I6 upwardly against the action of the springs I1.
I have shown my improved device when used to retain a punch in a fixture; however, it will be apparent that the die, associated with this punch may be likewise retained in a similar fixture block so that both punch and die may be conveniently replaced.
Among the many advantages arising from the use of my improved device, it may be well to mention that I have provided a relatively inexpensive hardened steel insert which may be conveniently secured in a relatively soft fixture block. Thus, the expense of special steel, hardening, heat treating the block, and grinding the tool receiving openings therein is dispensed with.
Still a further advantage results in that binding of the tool due to the distortions in the shank are negligible even when drills, reamers or milling cutters are used.
Some changes may be made in the arrangement, construction and combination of the various parts of my improved device without departing from the spirit of my invention and it is my intention to cover by my claims such changes as may reasonably be included within the scope thereof.
I claim as my invention.
1. A device of the character described comprising, a fixture having a pair of intersecting openings therein, one of said openings being cylindrical and being adapted to receive the shank of a cylindrical tool, while the other of said openings is of elongated cross section and so positioned that one flat side thereof intersects said tool opening, to an extent substantially less in width than the diameter of said tool receiving opening, a tool retaining unit of substantially the same size and shape as said elongated opening adapted to removably fit into said elongated opening, said tool retaining unit comprising a block having an inclined runway therein, a roller adapted to roll along said runway to position where it partially obstructs the tool receiving opening, said roller being longer than said line of intersection between said openings, said block having roller retaining edges on each side of said runway, and a pair of springs resiliently urging said roller into its obstructing position, said block and roller and springs being readily inserted as a unit into said fixture.
2. A device of the character described comprising, a fixture having a pair of intersecting openings therein, one of said openings being cylindrical and being adapted to receive the shank of a cylindrical tool, while the other of said open-- ings is of elongated cross section and so positioned that one fiat side thereof intersects said tool opening to an extent substantially less in width than the diameter of said tool receiving opening, a tool retaining unit of substantially the same size and shape as said elongated opening adapted to removably fit into said elongated opening, said tool retaining unit comprising a block having an inclined runway therein, a roller adapted to roll along said runway to position where it partially obstructs the tool receiving opening, said roller being longer than said line of intersection between said openings, said block having roller retaining edges on each side of said runway, the width of said runway and the length of said roller being both materially greater than the diameter of said retaining tool opening, a pair of springs resiliently urging said roller into its obstructing position, and a plate fixed to one end of said block which forms a support for said pair of springs, said plate forming a unit with said block and roller and springs, said block and roller and springs being readily inserted as a unit into said fixture.
HUGO O. REICHHARDT.