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Title: |
1911 Article-Jones & Lamson Machine Co., Automatic Screw Chasing Attachment |
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Source: |
Machine Tools Commonly Employed In Modern Engineering Workshop, V1, 1911, pgs. 88-89 |
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Insert Date: |
4/28/2022 2:05:32 PM |
For cutting screw threads on chuck work the automatic screw-chasing arrangement, illustrated in figs. 118 and 119, is provided. With this device screws can be cut of any diameter from 11½ in. down to 2¼ in. for internal screws, and down to 1 in. for external screws, over any length under 4 in. Upon the flat turret of the lathe there is mounted a tool-holder, which carries a 2-in. sliding cutter bar, and parallel with this bar there is a lead screw, the nut of which engages with the cutter bar. Rotary motion is communicated from the spindle of the lathe to the lead screw by means of the small shaft and bevel gearing shown in the illustration.
The cutter or chasing tool is mounted upon the cutter bar, which is moved longitudinally by the nut on the screw; and thus, as the spindle rotates, the chasing tool is fed forwards at a speed determined by the pitch of the leading screw. Threads of a definite pitch can be cut upon any diameter, in both right and left handed directions, with one lead screw and nut; but for each pitch a suitable lead screw and nut must be mounted in the tool-holder. When cutting parallel screws, the tool-holder is mounted squarely upon the turret; a key being provided for locating the true position. Taper screws of any angle may also be readily cut by setting up the tool-holder at the desired angle to the centre line. To regulate the depth of the operator moves the crosshead, which carries the work, forwards by the requisite amount the end of each stroke of the chasing tool. Automatic devices are provided for engaging and disengaging the nut, which operates the chasing bar. Fig. 119 illustrates the automatic chasing attachment engaged in chasing an external thread upon a piece of work held in the chuck of the machine, and the illustration also shows the simple cutting tools required for the other operations on the piece. |
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1911 Jones & Lamson Machine Co., Automatic Screw Chasing Attachment
1911 Jones & Lamson Machine Co., Automatic Screw Chasing Attachment in Operation
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