US2323608A

US2323608A - Instrument dial lock

Info

Publication number: US2323608A
Application number: US441757A
Authority: US
Inventors: Arthur S Kester
Original assignee: Rauland Borg Corp
Current assignee: Rauland Borg Corp
Priority date: 1942-05-04
Filing date: 1942-05-04
Publication date: 1943-07-06
Anticipated expiration: 1960-07-06

Description

July 6, 1943. KESTER 2,323,608

INSTRUMENT DIAL LOCK Filed May 4, 1942 Patented July 6, 1943 INSTRUMENT DIAL LOCK Arthur S. Kester, Chicago,

111., assignor to Rauland Corporation, Chicago, 11., a corporation of Illinois Application May 4, 1942, Serial No. 441,757

4 Claims.

This invention relates in general to instrument dials and more particularly to a manually controlled lock for precision, calibrated dials commonly used for controlling radio apparatus and laboratory instruments.

It is of extreme importance that dials of the above character be provided with a locking means whereby a particular setting may be secured against accidental displacement and it is of further importance that the locking means hold the dial securely without backlash and without exerting stresses in the dial or the dial shaft which may influence the calibration of the instrument.

Dial locks previous to this invention were objectionable because of the cost of the precise nature of the construction required and in many cases the operation of the lock disturbed the desired setting of the dial or otherwise exerted stresses in the dial structure which caused changes in calibration of the instrument to which they were attached.

In the present invention, the above objections are completely overcome by the unique combination of simple elements which, by simple manipulation, will rigidly secure a dial in any given fixed position.

A principal object of this invention is the provision of a manually controlled dial locking elements cooperatively related to a control dial whereby the said dial may be rigidly secured in any predetermined position of rotation without changing its position and otherwise stressing apparatus controlled by the dial.

Further objects and advantages of the invention will be apparent from the following description and drawing, in which Fig. l is a front elevation of a conventional Vernier dial with lock attached.

Fig. 2 is a cross sectional plan view of the dial taken through section lines 2-2, shown Fig. 1.

Fig. 3 is an enlarged fragmentary cross sectional side view of the dial lock taken through section lines 33, shown Fig. 1.

Fig. 4 is a fragmentary rear sectional view of the dial lock taken through section lines 4-4, shown Fig. 3.

One preferred embodiment of the invention is illustrated in the drawing in which Fig. l represents a conventional Vernier dial for the control of a shaft which operates a calibrated, variable capacitor not shown.

Referring to Fig. 1, the fragmentary outline 2 represents a panel on which a fixed ring member 1 is secured by suitable screw means as shown and has engraved thereupon a conventional vernier scale. A rotatable calibrated dial 3v is adapted to rotate in close proximity with the inner periphery of the ring member 1 and has integrally and concentrically mounted thereon} an operating knob 4 which carries a crank handle 5 for providing convenient manual rotation of the dial. Locking knob 6 is provided to manually secure the dial 3 in any predetermined position of rotation, the action of which will be hereinafter described.

The cross sectional view Fig. 2 shows the end of a shaft '1 to which the dial 3 is attached. The shaft is journaled in bearing 8 and runs to the apparatus to be controlled, such as a variable capacitor or other device requiring precision rotational movement. The flanged hub 9 is pinned to the shaft as shown and serves as a mounting medium for the rotative parts of the dial and dial lock. A thin, flexible, circular plate or disc 10 is held in concentric relation with shaft '1 between the face of the hub 9 and the inner face of the dial 3. The operating knob 4 is positioned concentric and adjacent to the outer face of the dial by three screws 1 l threaded into the flange of the hub 91. Thus when the operating knob 4 is rotated by means of crank 5, the dial 3 and the disc 10 will rotate concentrically with the shaft '1. A peripheral recess 12 in the inside surface of the ring member 1 provides a space wherein the outer edge of the disc 10 will freely move without interference when the dial 3 is rotated.

The locking elements are clearly shown in Fig. 3 in their unlocked position. A fiat spring 13 has one end secured to the panel 2 by rivets 14-14. A threaded nut 15 is integrally secured to the free end of the spring 13 and positioned through an opening 16 in the panel 2 with the upper side portion of the nut in close proximity with the inner face of the disc 10. A look screw 11, integral with knob 6, is fitted in the threaded hole of the nut 16. A hole through ring member I is provided for the free movement of the screw 11 therein. A look ring 18 is secured to the end of screw 1'1 to limit the outward range of the screw.

Referring to the rear view Fig. 4, spring 13, nut 15, and screw 11 are shown in their relative positions in respect to the edge of disc 10, show ing the area of the nut 15 which laps over the edge of the disc 10 for locking engagement which will be hereinafter described.

When the locking knob, Fig. 3, is rotated in the proper direction, its shoulder will bear against the ring I at l9 and the screw I! will draw the nut l5 toward the knob against the restraining action of spring l3 and clamp the outer surface of the disc l0 tightly between the side face of the nut and the inner surface of the ring member I, and thus lock the dial 3 against rotation.

It is to be noted that although the flexible disc I 0 will be slightly displaced, in an outward direction, from its normal path, this movement will not appreciably transfer stresses to the dial or the dial shaft 7 because of thehigh compliance of the disc in directions normal to its surface.

It is also to be noted that there is no vector of force tending to turn the disc about its center while the dial is being locked. It is further important to note that there will be a complete absence of lost motion between all the elements after locking because of the relatively high frictional contact at the outer surfaces of the disc I and high resistance to movement in both the disc l0 and the spring l3 in a direction parallel to their planes.

The locking device herein described is suitable for use with instrument controls that are adapted to move in linear paths as well as the rotational type of control described by a simple physical change in the plate or disc Ill whereby the effective outer surface will maintain a constant relation with the clamping surface of the threaded nut l5.

Having described my invention, I claim:

1. A device for locking an adjustable control member comprising a stationary support means, a control member movable in a predetermined path with respect to said support means, a plate aflixed to said control member, said plate resilient in directions substantially at right angles to its normal plane of movement, resilient lock means integrally secured at one end to said support means and positioned in close proximity with the surface of said plate, manually operative clamping means coac tively related with said lock means and said support, whereby the operation of said clamping means will move said lock means into frictional contact with said plate and thence move said plate into frictional contact with said stationary support means to secure said plate and said control member in a fixed relation with said support means.

2. A device for locking an adjustable control member comprising a stationary support means, a control member movable in a predetermined path with respect to said support means, a plate affixed to said control member, said plate resilient in directions substantially at right angles to its normal plane of movement, spring lock means having one end secured to said support means and its movable end positioned in close proximity with one surface of the said plate, manually operative clamping means coactively related with said lock means and said support, a fixed projection on said support means having an abut ting surface adjacent to the movable end of the said lock means, whereby the operation of said clamping means will move said lock means into frictional contact with the said one surface of said plate and flex said plate with its opposite surface in frictional contact with said projection to secure said plate and said control member in a fixed relation with said support means.

3. A device for locking a rotary control member comprising a stationary support means, a control member rotatably secured in fixed relation to said support means, a disc concentrically afiixed to said control member, said disc resilient in directions substantially at right angles to its normal plane of rotation, resilient lock means secured to said support means normally positioned in close proximity with one face of said disc, a fixed lock means positioned on said support means having a working surface adjacent to said resilient lock means, said resilient lock means and said fixed lock means normally positioned for the free movement of the outer faces of said disc to move freely there-between, manually operative clamping means coactively related with said resilient lock means and said support, whereby the operation of said clamping means will move said resilient lock means into frictional contact with said disc and flex said disc into frictional contact with said fixed lock means to secure said plate and said control member in a fixed relation with said support means.

4. A device for looking a rotary control member comprising a stationary support means, a control member rotatably secured in fixed relation to said support means, a disc resilient at right angles to its plane of normal rotation concentrically affixed to said control member, spring lock means secured at one end to said support means and having one surface of its free end in close proximity with the outer face of said disc and resilient only in a direction at right angles to the face of said disc, manually operative screw means coactively related with said lock means and said support means, whereby the operation of said screw means will clamp the outer faces of said disc between said lock means and said support means to secure said disc and said control member in a fixed relation with said support means.

ARTHUR S. I'CESTER.