US2022089A - Screw thread gauge - Google Patents

Description

Nov. 26, 1935. POND SCREW THREAD GAUGE Filed Dec. 13, 1932 mvmran By C MF nd A TTUBNEY Patented Nov. 26,

Pratt & Whitney Company Hartford, Conn a corporation oi New Jersey Application nic -1m 1s, 1932, Serial No. 647,005

6 Claim.

This invention relates to screw thread gauges and particularly to a gauge for testing screw -threads having freelyrotatable rolls forming the, gauging elements which are provided with screw threads on their work engaging surfaces.

An object of the present invention is to provide freely rotatable rolls in a screw thread snap gauge having threaded portions upon their cylindrical outer surfaces which form the-gauging elements of the rolls, these screw threads having the same lead as the screw threads to be gauged but being of the opposite hand.

Another object of the invention is to provide means to vary the axial position of the rotatable rollers so that in any rotative position they will properly contact with screw threads being gauged, each rotative position having a definite axial position.

And finally it is an object of the invention to provide cam means preferably formed upon one end of the rolls and engaging an abutment on the gauge frame whereby the rolls as they are rotated will be axially moved engaging positions.

A feature which enables me to accomplish the above named objects is that a positioning'pin is mounted in the gauge frame which engages an end face of a roll and a spring forces the roll axially so that its face-engages this pin, the end face of the. roll engaging the pin being provided with a helicoidal surface corresponding in lead to that of the threads formed upon its cylindrical surface.

with the above and other objects in'view my invention includes the features 01 construction and operat on setforth in the following-specifiing.

In the accompanying drawing annexedhereto f cation and illustrated in the accompanying drawand forming a part of this specification, I have shown my invention embodied in a screw thread gauge of the type shown in patent to Johnson,

No. 1,660,335 dated February 28, 1928, but it willbe understood that the invention can be otherwise embodied and that the drawing is not to' be' construed as defining or limiting the scope of the invention, the claims appended tothe specification being relied upon for that purpose.

. In the drawing:

Figure 1 is a side elevation of a complete gauge partly broken away to more clearly show a part of the construction.

Fig.- 2, is an end view of the gauge looking di- 7 r n amount determined by the lead of the thre ed portions of the.

rectly toward the gauging surfaces of the rollers.

Fig. 3 is an oblique view of one of the threaded rolls forming a work engaging member and showing the cam surface upon one end face; and

v Fig. 4 is an isometric view of a roll engaging spring;

In the above mentioned drawing I have shown but. one embodiment of the invention which is now deemed preferable-but it is to be understood-that changes and modificat ons may be made within the scope of 'theappended claims without departing from the spirit of the invention.

r Briefly and in its preferred aspect, my invention may include the following principalparts: 15 I First, a generally U-shaped frame having rolls mounted transversely within the. opposite arms, one or more pairs of rolls being in opposed rela- 'tion to each'other; second, supporting means for rotatably supporting the rolls in position, these 29 means preferably permitting adjustment to vary the distance apart of. opposing rolls; 'third,.abutments in the frame controlling the ax al ppsitions of the rolls and preferably adjustable so' that these positions may be'accurately deter- 25 mined; fourth, spring means resiliently holding the rolls against ther abutments; and fifth, cam means on the end face of the rolls, engaging its abutment, preferably in the form of a heliooidalv "surface, corresponding in lead to the lead of-go the screw threads on the rolls so that as the rolls are rotated by engagement with workpieces being tested the position of the work engaging surfaces of the'rolls will'always be correctly-disposed;

Referring more in detail'to the figures of the draw ng; .1 provide a U-shaped frame III of the same general type as that shown and described. in the above 'mentioned patent to Johnson. Within the opposite arms of this frame it) are 40 mounted transverse pins ll preferably having eccentric portions such "as are clearly shown anddescribed in the above-mentioned Johnson pat ent. Upon this eccentric portion threaded work engaging rolls l2 may be mounted for free rotation; As the construction of the pin II and its eccentric portion is or may be similar to that described in the above mentioned patent, further description is not thought to be necessary. It will be noted, however, that the rolls l2 in the present invention have upon their outer cylindrical surfaces screw threads i3 extending throughout their length. These screw threads l3 have the same -lead as the screw threads to a roll l2. Preferably and as shown, this pin l .varied axially of the roll I2.

2 7 be tested, but have their helix vof .the opposite hand. The gauge shown in Fig. 2 having lefthand threads is therefore designed particularly for g'auging right-hand threads.

As rotation of the threaded roll the position of the grooves and ridges forming the part of the threads l3 directly engaging the screw threads being tested, means are provided,

for maintaining these positions correctly for any rotative position assumed by the rolls. For that purpose springs H of generally flat leaf form engage one end of a roll l2 and force it axially toward the opposite face of the frame l0. Limitingthe movement of the rollsin direction is an abutment IS, the position of which may be slightly varied so that the rolls l2 for any one rotative position .may be correctly determined.

As shown in Figs. 1 and 2, this abutment l5 comprises a pin formed on the inner end of .a short screw threaded member 16 threaded into a side of the frame Ill so that the inwardly extending pin portion i5 thereof engages an end face of a is formed somewhat eccentrically relative to the axis of ,the member. lli'so that by rotating the screw it the position of the pin will be slightly In any adjusted position the screw it may be locked by a short check screw l1 bearing upon the outer end of the screw I6.

when a roll I 2 is correctly adjusted for'one rotative position it will becorrect' for all rotative positions.

In operation the pins ll supporting a pairof rolls I! are adjusted for the proper distance apart,

for gauging, a particular size and type of screw threads and the pins l5 are so adjusted that the 7 threads upon the rolls I! will properly intermesh with corresponding grooves and ridges of the screw threads being tested. Thus adjusted the rolls I! may rotate due to engagement of the work being tested during the gauging operation but in any rotative position of the rolls If they will be in proper mating relation for engagement withscrew threads being tested.

In Fig. la supplementary pair of rolls I8 is I shown which may be provided with gailgm surfaces for testing a diameter or other function not requiring screw threads on its surface.

I: would vary aoeaoeo What I claim is: h 1. A screw thread gauge comprising in combination, a U-shaped frame, opposed screw threaded rolls rotatably supported in opposite arms of said frame, means to adjust the distance 5 apart of said rolls, and means to cause axial movement of said rolls in timed relation to their rotation.

2; A screw thread gauge comprising in combination, a. frame, opposed screw threaded rolls l0 rotatably supported in said frame, means to set said rolls for predetermined gauging dimensions, resilient means normally holding said rolls toward one axial position, said rolls having a helicoidal surface at one end and means on said frame engaging saidhelicoidal surface whereby said rolls are caused to move axially as they are rotated. v v

3. A screw thread gauge comprising in combination, a frame, opposed-gauging elements sup;

ported within said frame one of which elements. is a screw threaded roll rotatably mounted in said frame and having screw threads on its outer cylindrical surface of the same lead as the screw threads to be tested, said rolls having a helfcoidal surface on one end, resilient means forcing said rolls in one direction, and means engaging said surface and coacting with said resilient means causing said roll to move axially in accordance with its lead as it is rotated.

a 4. A screw thread gauge comprising in com- 4 bination, a frame, opposed gauging elements within said frame one of which elements is a screw threaded roll, means to support said roll for rotation-about its axis, means to adjust the axial position of said'roll, and means to cause axial movement of said roll in accordance with the lead of its screw threads as the roll is rotated. '5. A screw thread gaugecomprisin'gin combination, a frame, opposed gauging elements 40.

within said frame, one of whichelements is a I screw threaded roll having the same lead as the screw threads to be gauged and'being freely rotatable about its 'axis, a, spring engaging one end and normally forcing said roll axially in one direction, and a pin engaging the opposite end of said roll for limiting said movement, the endface of said roll-engaging said pin having a helicoidal surface corresponding in lead to the screw threads on said roll whereby rotation of said roll forces said roll axially .and maintains the screw threads on the roll in correct gauging position.

6. A screw thread caliper gauge comprising a frame, a pair of 0Dposing, screw threaded, freely rotatable gauge rollers in said frame, one of said 5 rollers being axially displaceable and springcontrolled. I

CHARLES M. POND.

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