US1448222A

US1448222A - Circular micrometer

Info

Publication number: US1448222A
Application number: US560136A
Authority: US
Inventors: Charles F Johnston; Lloyd A Martinelli
Original assignee: Individual
Current assignee: Individual
Priority date: 1922-05-11
Filing date: 1922-05-11
Publication date: 1923-03-13
Anticipated expiration: 1940-03-13

Description

MMaur.. 13, 1923.

`. c.' F'. JoHNsroN r-:T AL

CIRCULAR MICROMETER Filed May 11, 1922 W7 mw between the anvil 22 and the edge L23 drawing together the finger members 13 and 14 as for example the width of the ring 24 between the faces 22 and 23. The graduations at 21'read on the vernier'scale 16 and give the exact ring widths. Other finger members as 15 may be established at intervals, so as to make the drawing together of the movable slide by its finger engaging end 13 for different diameters.

It is to be understood that the piston ring joint is to be tightly drawn together to establish the true ringdiameter.

In making measurements of circles within the loop itis to be understood that the circular diameter is to bear against the ribbon which in turn bears against the track 2 at-the point 30; and again against the fulcrum point 7,A thus making two points of contact for the circular periphery. The ring 13 shown in full lines in Fig. 1 is not yet fully drawn up, the joint 2O not being closed, and when so fully drawn up will occupy the position of the dotted lines 31. The lower portion of the base plate 1 we prefer to cut I throughl as on the line 32 so as to permit circular pieces of maximum size' to pass-l clearly through the said opening. A slide plate 33 is provided and is inserted in suitable grooves as34 bringing the base'plate surface" Hush under the measuring loop at times when the device isemployed for measuring thin discsl or piston rings, the saidslide 33 being withdrawn, however, as by the finger engaging portion 35 when it is de'siredto measure a piston or other cylindrical object having considerable length and which may then pass freely through the opening 32 in the said plate.

While we have shown but one form of our device, it will be understood that it may be i readily built in other forms and the invention embodied in other structures and we desire to beunderstood as claiming such varithe track. y

track and slide thereon, a 'flexible inexten- 4 ifi/M5222 sible ribbon having one of its ends fixed to said slide and a body portion forming a loop to embrace an article to be measured and its other end fixed with relation to said track during movement of said slide, a finger member on the slide and another finger member fixed with relation to the track whereby the slide may be moved on the track and the said ribbon thereby caused to embrace said article, a scale on which the inovement of the slide is readable, and a base in fixed relation with said track having an opening therethrough adjacent said loop adapted to permit objects to be positionedv ysaid slide and a body portion forming a loop to embrace an article to be measured and its other end Fixed-with relationy to ksaid track during movement of said slide and means adapted to adjust vthe position of the slide with reference to the fixture of the ribbon and the track.

3. A circular micrometer, comprising a track and slide thereon, a flexible inextensible ribbon having one of its ends fixed to said slide and a body portion forming a loop to embrace an article to be measured and its other end fixed with relation to said track during 'movement of said slide, a iinger member on the slide and another finger member fixed with relation to thetrack wing therethrough adjacent said loop adapted vto permit objects to be positioned through the loop and the base, and means adapted to adjust the position of the slide with reference to the fixture of the ribbon and ciments r. Joiiivsroiv. Liiovn A. MAiiriNnLLi.