US2090178A - Feeler gauge - Google Patents

Description

1937. A. J. BRICKNER 2,090,178

FEELER GAUGE Filed Jan. 15, 1936 Wm mm? Meme Patented Aug. 17, 1937 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to a feeler or tracer adapted to be used principally on duplicating machines, by means of which parts are duplicated from and in accordance with following a prepared model or pattern. Feelers or tracers of this character may be used in many relations and with the device Which I have constructed, it is so designed and arranged that as soon as the projecting feeler pointer thereof comes into contact with a surface point of the model or pattern, an electric circuit is closed, which operates either directly or through a suitable relay, to the control of the duplicating mechanism, for example, it may be used to control the motion of the feeds of the duplicating machine; or the feeler or tracer may be used for actuating a signal such as lighting a small electric light, ringing a bell, or the like.

Feelers or tracers of the character noted operate within very small limits of dimension and are, therefore, in operation respects of a delicate character. With my invention, notwithstanding the delicacy of the feeler operation the device is sturdy and not likely to be thrown out of ad- 25 justment even upon long and hard use. One very decided advantage of this tracer or feeler is that, irrespective of the angle of contact of the feeler finger or pointer relative to the model or pattern against which it engages, the circuit will be closed and the effects of the designed circuit closing follow.

One construction embodying my invention is shown in the accompanying drawing, in which,

Fig. 1 is a side elevation of the feeler or tracer of my invention illustrating it in use as contacting with an irregular surface of a model or pattern.

Fig. 2 is a central longitudinal section through the feeler, and

Fig. 3 is a similar fragmentary section at the pointer end thereof showing the operation of the same when the pointer is slightly turned at an angle to its longitudinal axis.

Like reference characters refer to like parts in the different figures of the drawing.

In the construction, a tube of uniform diameter is provided exteriorly threaded at what may be termed its rear end, over which a cap 2 is screwed, in the bottom of which is an opening 3. The other end of the tube l is interiorly threaded and is closed by a member 4 which has a central opening 5 and from which at the inner side an integral exteriorly threaded sleeve 6 extends, the sleeve being formed at its inner end with curved surfaces at l which provide a curved ll passes, the front end thereof being equipped 10 with a disk-like head l2, between which and the block 8 and surrounding the guide 9 is a compression spring IS, the tendency of which is to move head l2 and rod I! in a forward direction, that is, to the right, looking at Fig. 2.

A member having a head 14 with a spherical forward surface has a flat rear side to bear against the outer or forward side of the disk head I 2. The curved surface of the part I4 bears against the complementary curved surface 1 previously described, being held thereagainst by the pressure of the spring l3. A stem l5 having a diameter slightly less than the diameter of the opening 5 in the member 4 extends from the head M in axial alinement with the rod I l and through the opening 5. At its outer or forward end a pointer [6 may be detachably secured. The method of attachment is fully illustrated in Fig. 2. Different pointers having different shapes at their outer ends and of different lengths may be used as the type or character of the work to be done may require.

Back of the block 8 and within the tube l a tubular member I! is secured in place by a set screw l8 (see Fig. 2). It may be adjusted to a desired position and then rigidly secured against movement. A multiplying flexible lever l9 extends lengthwise of and within the tubular member IT, at its forward end having downwardly projecting ears. 2E: which are pivotally connected to an inwardly extending lug 2| struck from or integral with the tubular member ll. The forward end of the movable lever I9 is rounded and bears against the rear end of the rod H against which it is held by a coiled spring 22 under compression, which is located between the under side of the lever l9 and the adjacent under portion of the tubular member IT.

The movable lever 9, at its rear end, carries a contact 23 at its underside which is positioned directly above a second contact 24 secured to a metal bar 25, which in turn is carried by a sleeve 26 of electric insulating material threaded into the rear end of the tubular member H. A circuit wire 21 is connected in any suitable manner to the rear end of the bar 25, see Fig. 2.

It is apparent that a slight rearward movement of the rod II causes the contact 23 to be moved downwardly to engage the contact 24. The voltage in the electric circuit is low whereby when the contacts 23 and 24 are together the body I of the tool may serve as a ground for the circuit. A rearward movement of a very small amount, measured in thousandths of an inch, causes an engagement of the contacts 23 and 24 and a clos ing of the circuit which, either directly or through a suitable relay, may be used to control duplieating machinery, or may be used to close a circuit for energizing a signal or alarm.

In Fig. l the feeler or tracer is shown mounted upon a support 28 which may be moved toward and away from a pattern or model 29 having a surface 30 with which the free end of the pointer I9 is to engage. When the support 28 is moved toward the pattern 29 as soon as the end of the pointer I6 engages a point of the surface 39, the pointer I6 and associated parts are moved either directly back or tilted as shown in Fig. 3. In either case a slight movement of the pointer closes the circuit by bringing the contacts 23 and 2 together and sets in operation whatever sequence of operations or results follows from such circuit closing as previously described.

It is apparent that the tubular member I! with the insulating sleeve 26 therein carrying the contact 24, and with a multiplying lever I9 pivotally mounted may be assembled as a unit and readily inserted into the rear end of the tube I until the rounded end of the lever I9 engages the rear end of the rod I I, and then by adjustment the spacing of the contacts 23 and 24 may be controlled so as to have the space the amount desired. By reason of the relatively large movement given to the movable lever I9 following from a very short longitudinal movement of the rod I I, the contacts 23 and 24 may be brought together by a movement of the rod II measured as a very minute distance.

The structure described is sturdy and reliable and capable of withstanding severe usage without getting out of order.

The invention is defined in the appended claims and is to be considered comprehensive of all forms of structure coming within their scope.

I claim:

1. In a precision measuring instrument of the class described, comprising, a body of cylindrical shape, open at the ends, said body having fastening means at each end, a plug member having a spherical seat interiorly thereof at one end and a restricted opening of predetermined size at its other end, a rod having a semi-spherical head adapted to be universally mounted within said seat, said plug member having fastening means cooperatively associated with the first mentioned fastening means, the rod passing through the said restricted opening, a block, having an outer diameter substantially equal with the inner diameter of the said body member and having an axial opening therethrough, located within the said body member, means for mounting the same adjacent the plug member, a rod, having a disk head, slidably mounted in the said axial opening with its head closely positioned to the flat side of the semi-spherical member, spring means located between the block and the disk head whereby the disk head urges the rod to extended position, means, including a multiplying lever adapted to be cooperatively associated with the said rod, cap means, engageable with the fastening means on the other end of said body, for holding the last mentioned means in position.

2. An article of manufacture of the class described comprising a cylindrical hollow body member, a hollow plug member located at one end thereof, said hollow plug member having its inner end shaped to form a spherical seat and its outer end having an opening therethrough, a contacting rod element extending through the said opening, a semi-spherical head attached to said rod element and receivable within the spherical seat for limited universal movement, a block member, having an axial opening therethrough, snugly receivable within the said cylindrical body between its ends, means for holding it in position relatively thereto, a rod member slidably mounted within the opening through the block member, a disk on the rod at the end adjacent the semispherical head, spring means between the disk and the block member, a tubular member likewise snugly receivable and adjustable within the body member, a movable lever pivoted on the inner end of the tubular member and bodily movable therewith, said lever having one portion, closely adjacent the pivot, in contact with the end of the rod and a second portion having a contact button thereon, said contact button being located a relatively long distance from the pivot, a second contact button, means for mounting the second contact button on the tubular member and means engaged with the body member to hold the tubular member in position.

3. A combination of elements as set forth in claim 2 in which the means for mounting the second contact button includes a sleeve threaded into the tubular member whereby axial movement of the button is had.

ARTHUR J. BRICKN'ER.

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