US3151598A

US3151598A - Turns-indicating knob

Info

Publication number: US3151598A
Application number: US252904A
Authority: US
Inventors: Marlan E Bourns; Wylie A Stout
Original assignee: Bourns Inc
Current assignee: Bourns Inc
Priority date: 1963-01-21
Filing date: 1963-01-21
Publication date: 1964-10-06
Anticipated expiration: 1981-10-06

Description

1964 M. E. BOURNS ETAL 3,151,598

TURNS-INDICATING KNOB Filed Jan. 21, 1963 INVENTORS 'MARLAN 1 Baum/ WYL/E A. 570a:

United States Patent 3,151,598 TURNS-INDICATING KNOB Marlan E. Bourns, Riverside, and Wylie A. Stout, Arlington, Calif., assignors to Bourns, Inc. Filed Jan. 21, 1963, Ser. No. 252,904 13 Claims. (Cl. 116--115) The invention herein disclosed pertains to indicator devices that are useful for indicating the number of turns and fraction of a turn through which an adjusting shaft is rotated from a prescribed rotational starting position or zero. Actuating or adjusting shafts of the type here of concern are found, for example, in multiturn rotary potentiometers, in which instruments rotation of the shaft serves to variably position a movable electrical contact along an exposed face of a helical resistance element that is disposed in coaxial relationship with the shaft. For illustrative purposes only, the present invention will be described in connection with such an instrument, it being understood that the exemplary illustrated physical embodiment of the invention is capable of use and operation with other devices or instruments wherein the rotation of the actuating shaft through a number of revolutions, twenty forexample, drives the instrument through its effective operating range. The primary purpose of turns-indicators is to facilitate rapid return or setting of the actuating shaft and the operated part to previously occupied positions. A subsidiary purpose is to provide a visible indication of the position of the operated part relative to the end positions of its movement range.

In the prior art many differing constructions of muliple' turns counters or, turns-indicators have been marketed. Many utilize gearing or like expensive parts in providing indications of complete turns and fractional-turn rotation. Many of shaft-adjusted instruments are mounted on or at the rear ofa panel or the like through which the actuating shaft extends, and accordingly it is undesirable, in general, for the indicator to occupy a large space. Many of prior art turn-indicators are such that reading indications of two widely spaced-apart members, one for full turns and the other for fractions of one turn, is required, making reading unnecessarily diflicult and more prone to error. Quite often the turns-indicating means are combined with knob-means or the like that are utilized to facilitate rotation of the adjusting shaft. The indicator means are in instances added onto the exterior of the knob, or utilize a set of indicia that are inscribed upon or otherwise carried by the panel on which the instrument is mounted.

The aforementioned undesirable features of prior art shaft-position indicators are avoided by the present invention. According to the invention, the operating structures necessary to give movement to indicating devices take the place of the usual operating knob. The indicating devices are very simple, comprising a stationary dial or plate bear-ing indicia, a handlike mark applied as by painting on a transparent crystal or cover, and a rotatable hand. The indicating devices are arranged at the outwardly-facing end of the knob-like operating structure that serves as the adjustment knob, and present an easily-read indication similar to that presented by a time clock or watch. Thus the panel space required is exactly the same as that required by the normally-used solid knob, and indicia or other marking on the panel is not necessary. The indicating structure, being at the outer end-face of the knob-like operating means, is clearly visibleduring adjustment of the shaft. The device according to the invention has the shape and general configuration of a shaft-operating knob, is mounted" upon and secured to a shaft by the same means and in the same manner as a conventional knob, and hence supplants and replaces the usual knob. Being devoid of gears and constructed of very few and simply and easily assembled parts, the device is inexpensive, yet very effective.

In general the preferred form of the invention comprises a support arranged to be secured to the forwardly extending adjustment shaft, for rotation of the shaft, by means of a set screw. The support has affixed thereto a lens or crystal and a generally cylindrical structure or barrel that is adapted to be manually rotated. .Thus manual rotation of the barrel effects rotation of the shaft. The lens or crystal, hereinafter called a window for convenience, bears a pointer or hand that may be painted on the inner surface of the lens, and it further serves to hold against a panel the rear end of a stationary cylindrical guide and retainer device. The retainer part includes an annular dial, and serves to retain in place a floating rotary device or wheel that carries a second hand or pointer and is intermittently rotated by cam-and-transmitter means incident to rotation of the outer barrel. The stationary cylindrical guide bears the cam means for inducing intermittent rotation of the wheel, and preferably also serves to stabilize the rotatable barrel. The wheel is rotatable on the support, and is retained in any of predetermined angular positions indicating full turns (or full turns and half turns) by a simple spring detent that yields each time the cam means induces a step of rotation. Thus as the barrel is rotated the first pointer is concurrently rotated over the face of the dial to provide indications of fractional portions of a full turn, and the second finger is intermittently stepped to indicate full turns of the shaft.

The preceding brief general description of a physical embodiment of the invention indicates that it is a principal object of the invention to provide improvements in turns-indicators for instruments having an adjusting shaft that is rotated to effect adjustment of the instrument.

Another object of the invention is to provide a simple turns indicator for indicating the extent of rotation of an adjusting shaft from an initial position.

An additional object of the invention is to provide a device that may be used in place of a shaft-operating knob for rotatively adjusting the shaft and which device Will provide easily read indications of the extent of rotation of the shaft from an initial position.

Other objects of the invention will hereinafter be set out in the claims hereto appended or made evident in the following description of a preferred exemplary embodiment of the invention as depicted in the accompanying drawings. In the drawings:

FIGURE 1 is a view of a panel-mounted ten-tum instrument with a preferred exemplary form of the invention mounted thereon;

FIGURE 2 is an end or face view of the turns-counting or indicating device depicted in operating position on a panel-mounted instrument in FIG. 1;

FIGURE 3 is a sectional view of the preferred exemplary embodiment of the invention, enlarged for clarity of detail, taken as indicated by line 33 in FIG. 2;

FIGURES 4, 5 and 7 are fragmentary sectionial views of the structure depicted in part in FIG. '3, taken as indicated by lines 4-4, .55, and 7-7, respectively in FIG. 3; and

FIGURE 6 is a face view similar to FIGURE 2 of the dial indicator following rotation of the instrument shaft through one and three-tenths turns.

Referring first to FIG. 1, there is denoted generally by numeral 10 a knob-like structure or device according to the invention as constructed to accommodate an instrument shaft rotation of ten turns (3600") or less. The device is illustrated as being mounted on the adjusting shaft of an instrument 12 in the form of a ten-turn rotary potentiometer that is in turn affixed tothe rear face of a panel 14. Next referring to FIG. 3, it is noted that the instrument 12 comprises a threaded bushing 12b that extends through an aperture 14a formed in the panel 14, the bushing bearing a nut 1211 by means of which the bushing and instrument proper are held rigidly to the panel. Additionally the instrument comprises an adjusting shaft 12s rotatably mounted in the bushing 12b and extending outwardly and forwardly therefrom. The free end of the shaft comprises the portion upon which a conventional adjusting knob is usually secured.

The exemplary embodiment of the invention utilizes supporting means comprising a generally tubular support (FIG. 3) that is bored to receive and be secured to an end portion of the instrument shaft 12s. Any suitable means may be used to affix the support to the shaft, but as illustrated the support is secured to the shaft by set screw means comprising a set screw 29s. The reduced forward end 20 of support 24) is axially bored and tapped to receive a screw 22. The screw 22 serves to firmly secure to the support for unitary rotation in unison therewith a hollow shell means which with the support serves as the essential elements of a manually-rotatable knoblike means for imparting rotation to the instrument shaft. The shell means in the illustrated embodiment comprises at the outer end thereof a transparent lens or window 24 the beveled outer periphery of which is tightly fitted into a counterbored outer end of a hollow cylinder or barrel 26 forming a part of the shell means. The window or lens 24 and the cylinder may be firmly secured together, as by adhesive or the like, so that torque applied to either is applied through the support to the instrument shaft. Lens 24 has applied thereto on its inner face an indicator in the form of an outer pointer 24p, for a purpose presently more fully explained. The pointer 24p may be painted on lens 24, as previously indicated. Barrel 26 is rotatably disposed around stationary means which in the illustrated form comprises a generally cylindrical sleeve 28, the rear end of which abuts against the front face of p panel 14. The sleeve is retained in position by reason of an annular step 28s formed on the exterior of the sleeve, the step being engaged by the rear end face of the barrel when the device is pressed onto shaft 12s and the set screw means are tightened. The sleeve 28, or other part of the stationary means, also comprises cam elements presently to be described.

Secured to or forming an integral part of the forward end of sleeve 23 is an annular ring 28r. Secured to the outer end face of ring 28r (or, alternatively, integral with the ring) is an indicia-bearing indicator means in the form of a disk 30. The disk is provided with marks indicating subdivisions of 360, and numerical indicia which preferably commence with zero and are equal in number to the number of turns shaft 12s must be rotated to operate the instrument through its complete range. Thus the disk and indicia serve as a dial. In the exemplary device used with the exemplary ten-turn potentiometer the numerical indicia are as depicted in FIGS. 2 and 6; however other sets of indicia may be used. The disk or dial is annular in form, to provide an opening through which the front end of support 20 extends.

Rotatably mounted on support 20 and bearing on rear and forward steps 20a and 20b, respectively, of the sup port, is an intermittently rotatable means comprising an externally toothed rotatable manner 32 hereinafter called a wheel. The wheel, as is indicated in FIGS. 4 and 5, is formed to have a set of axially extending projections or teeth 32t between next-adjacent ones of which teeth are axially-extending grooves that preferably are of substantially circular-arc cross-section. The teeth and intervening grooves are engaged by a driving member or transmitter and by detent means presently to be described, whereby the wheel is alternatively driven and retained stationary, for purposes or reasons also presently explained; Secured to the reduced-diameter front-end or hub portion 32h (FlGl 3) of the wheel 32, is an indicator device in the form of an inner pointer 32p which preferably is formed as an annular ring closely fitting on hub 32h and secured thereto and having an integral projection forming a pointer or hand that cooperates with the numerical indicia on disk 30 to provide indications of full turns through which shaft 12s has been rotated from an initial or zero position. The arrangement of inner pointer 32p relative to hub 32h, dial disk 30 and the indicia thereon is illustrated in FIGS. 2, 3 and 6.

Secured in a bore formed through a rim portion of support 20 (FIG. 3) generally opposite set screw 20s, is a transmitter means comprising a resilient reed 34. A notch or slot Ztin (see also FIG. 7) is provided in the rim of the support, in which notch a free portion of the reed can partake of radial bending movements under the influence of actions presently to be described. Mounted on the free end portion of the reed 34 and preferably rotatable thereon is a dog or transmitter 36. The reed is normally straight and thus transmitter 36 normally is in an idle or inactive position in which it travels along a first circular path and in contact with or close to one or another of a set of surfaces 28v, 28w (FIG. 4) intervening between specially spaced and formed projections or cams 280 formed or otherwise provided along a portion of the interior periphery of stationary sleeve 28 and in said first circular path. Thus it is evident'that upon rotation of shaft 12s and support 20, the reed 34 and transmitter 36 are carried around within sleeve 28, and transmitter 36 engages or collides with one of the cams and is forced radially inwardly away from the first (outer) circular path into a second (inner) circular path, and, after riding over a cam, is returned outwardly to the first path by the energy stored in the resilient reed during the inward motion. Obviously the same action occurs irrespective of the direction of rotation of shaft 12s. As is made evident by examination of FIGS. 3 and 4, as the transmitter 36 is forced inwardly as it engages one of the cams during rotation around the axis of the shaft, it is moved into one of the grooves 32g intervening between next-adjacent ones of projections or teeth 32t of wheel 32. Since the reed and transmitter are forced to rotate about the axis of the shaft in unison with the barrel and support 20, engagement of the transmitter with a tooth of wheel 32 causes rotation of the latter and displacement of inner pointer 32p.

Rotation of wheel 32 by the transmitter is thus restricted to discrete steps of movement; preferably and as herein disclosed, to twice as many steps as the number of full turns or revolutions of shaft 12s necessary to accomplish full-range variation of instrument 12. The angular dimensions and dispositions of the cams and teeth are thus governed by the number of full revolutions of shaft 129 required to adjust the instruments through its entire adjustment range. Also, the wheel is preferably locked or yieldingly restained against undesired rotation during the indeterminate variable operating interval or I period between stepwise rotational movements. To those ends, a shaped resilient spring detent 38 (FIGS. 3 and 5) is provided, which detent has the ends of its horns anchored in respective radial slots that are provided for the purpose in ring ZSr. The intermediate or middle part of the detent 38 is formed as indicated in FIG. 5 for close seating in any of grooves 32g and for cooperation with any pair of teeth 321 to forcibly but yieldingly restrain wheel 32 from unintended rotation. The free unanchored body portion of the detent is resilient and accordingly yields and permits the middle part to ride out of a groove and over a tooth into a next-adjacent groove when transrnitter 36 forcibly rotates the wheel. Thus it is evident that during each revolution of shaft 12s as barrel 26 is rotated, the'transmitter will encounter each of the set of cams (of which-there are two in the illustrated embodiment) and will be forced inwardly and thereby rotate the wheel and inner pointer 32p through a definite fractional part of a turn in the same rotational direction as that of vthe barrel. As is also evident, the rotation of the barrel 2-6 andlens or window 24 will move 'outer pointer 24p around the series of indicia through precisely the same angular extent of rotation as that of adjustment shaft 12s. As a consequence, outer pointer 24p will, during each revolution of the shaft, provide a readily-perceptible and very accurate indication of the fraction of .a turn the shaft has been rotated from the initial or zero position. Also, inner pointer 32p will, during a series of successive revolutions of the shaft from zero position, furnish indications of the number of full (360) turns through which the shaft has rotated. Thus, with the instrument set at the initial or zero end of its range of adjustment, with the

pointers

32p and 24p set at zero positions, and the set screw means then tightened to affix the illustrated exemplary (IO-turn) device to shaft 12s, rotation of the barrel in the forward or clockwise sense as viewed in FIG. 2 will during the first one-third of a revolution move only outer pointer 24p of the indicator pointers. Then, during the second one-third of the first revolution, the transmitter will engage one of cams 28c and enter a groove of wheel 32 and rotatepointer to a position approximately midway between numerals and 1 on disk 30. Then as forward rotation continues and outer pointer 24p approaches and passes numeral 0, the transmitter will engage another of cams 28c and cause rotation of wheel 32 through another step and to a' position at which inner pointer 32p points to numeral 1 on the dial or disk 30. The actions will be generally repeated during each succeeding' revolution of the barrel and shaft, inner pointer 32p stepping twice during each 'revolution. During return movement of the instrument by subsequent backward rotation of the barrel and shaft,the stepping of wheel 32 and its inner pointer 32;; will be in the return direction. The illustrated embodiment of the device'accordi'ng to the invention is arranged for use with an instrument having an adjustment shaft that is rotated clockwise from the zero or'initialposition. Obvious rearrangement of the indicia to read counterclockwise is contemplated in a similar device for use with an instrument operable in the counterclockwise direction from the initial position.

For decoration and reinforcement of barrel 26, a ring 40 (FIGS. 1 and 3) may be affixed to the end'of the barrel. The barrel may be provided with longitudinally-extending fiuting 26] (FIGS. 1, 4 and 5) whereby to facilitate manual rotation of the barrel, and, optionally for another purpose. Thus, in these instruments in which it is desired tosecure or lockthe instrument in a particular position of adjustment, a closely fitting internally fluted cy lindrical band or slide 42 may be used in conjunction with complementary flutin'g formed on the rear step 28! of sleeve 28 (FIG. 3), the fiuting being complementary to that on barrel 26. Thus with slide 42 inthe dashline position indicated in FIG/3, in which the slide is wholly on barrel 26, the barrel may be rotated to any desired rotational position withoutrestraint from slide 42. Thereafter, theslicle 42 may be pushed back to the full line position indicated in FIG. 3; in which position it is engaged'with'both the'barrel' and sleeve 28, and thus serves to lock the barrel to the sleeve. Sleeve 28 is prevented from rotating by a projection 44p' (FIG. 3) provided on the instrument lock-washer 44, which projection is arranged to be disposed in a complementaryslot 28m provided in the lower rear edge of sleeve 28. .Thus the slide may be used to lock the barrel to-stationary structure and prevent accidental rotation of the barrel and the shaft of the instrument. To then permit change of adjustment or setting of the instrument the slide 42 is drawn forwardly until it is free of sleeve 28 as indicated in the dash-line position inFIG. 3.

The preceding description of a preferred exemplary embodiment of theinvention illustrates the attainment of the aforementioned objects. It is evident that in the light,of the disclosure, modifications, such as changes of form, within the, true spirit and scope ofthe invention will occur to those skilled in the art. For example, it is obvious that parts'28, 28r, and 30'may be formed as a single casting as by injection-molding; and the same is true of

parts

26 and 40. Accordingly it is not desired to limit the invention to the exact structure of the preferred exemplary embodiment illustrated and described, but we claim:

1. For an instrument having an adjusting shaft rotatable through a plurality of revolutions in effecting adjustment of the instrument throughout its adjustment range, a turnsindicating knob structure comprising:

first means, including a support device having a bore along an axis and adapted for mounting upon the instrument shaft coaxially with the shaft, said device including means to secure the support device to the shaft for positive rotation in unison with the shaft about the axis thereof; second means, comprising rotary means secured to said support device and providing a knob-like exterior adapted to be manually rotated for rotation of said support device and the instrument shaft, said rotary means comprising a transparent window disposed transversely of said axis and providing an outer end face for the rotarymeans, said rotary means bearing an outer indicator movable in unison therewithand visible through said transparent window; third means, including stationary means encircling at least a portion of said support means and having cam means and an indicia-bearing dial having a face area visible through said window; fourth means, comprising a toothed device rotatably mounted on said first means and an inner indicator pointer thereon arranged closely-adjacent to and in front of said dial, said toothed device having a peripherally disposed set of teeth; and movable transmitter means carried by said support device for rotation therewith and disposed in the path of said cam means and movable thereby into engagement with a tooth of said toothed device whereby said toothed device is intermittently rotated incident to rotation of said support device to move said inner indicator pointer relative to said indicia,

whereby said inner indicator pointer and said outer pointer move relative to said indicia to indicate full turns and fractions of a turn, respectively, of said support means.

2. A turns-indicating knob structure according to claim 1, said stationary means comprising generally cylindrical sleeve means coaxial with said support device and having an exterior bearing surface coacting with said rotary means.

3. A turns-indicating knob structure according to claim 1, said stationary means comprising an externally-serrated. generally cylindrical surface, and said rotary means comprising a complementary similarly externally-serrated generally cylindrical surface, and lock means, comprising an internally-serrated band coaxial with said support means and movable longitudinally for concurrent interengagement of the internally-serrated surface thereof with the externally-serrated surfaces of said stationary means and said rotary means to lockthe rotary means to the stationary means to prevent inadvertent rotation of the rotary means, and said band being longitudinally movable to a position out of engagement with one of said externallyserrated surfaces.

4. A turns-indicating knob structure according to claim 1, said dial bearing numerical indicia in serial order commencing with zero and equal in number to the number of revolutions required of said shaft for adjustment of the instrument throughout its range, and said cam means comprising a plurality of cams uniformly spaced about the internal periphery of said stationary means, whereby said inner pointer is advanced in stepwise movement betwen next-adjacent ones of said numerical indicia.

5. A turns-indicating knobstructure according to claim 1, said cam means comprising two uniformly-spaced cams and said toothed device Comprising N uniformly-spaced teeth where N is an even whole number, and said cams each being of configuration to move said transmitter to engagement with a tooth of said toothed device through a fraction of one revolution of said rotary means, said fraction being expressed as l/N, and the instrument shaft being rotatable through N/Z revolutions to operate the instrument through the complete adjustment range thereof.

6. A turns-indicating knob structure according to claim 1, including resilent means secured to said stationary means and pressing said toothed device whereby to yieldingly retain the latter in any position to which the toothed device is rotated by said transmitter.

7. For an instrument having an adjusting shaft rotatable through a plurality of revolutions in effecting adjustment of the instrument throughout its adjustment range, a turns-indicating knob structure comprising:

first means, including a rotary structure having a bore for reception of an end portion of the adjusting shaft of the instrument, said rotary structure including means to secure the rotary structure to said shaft for rotation in unison therewith, said rotary structure comprising a generally cylindrical shell adapted for manual rotation and having an end member providing at least a circular transparent window and an outer pointer rotatable therewith; second means, comprising stationary means mechanically connected to said first means and including a dial having at least annular face visible through said window, said dial bearing a circularly arranged set of indicia visible through said window, and said stationary means comprising cam means;

third means, comprising rotatable means mechanically connected to said first means and having an inner pointer means rotatable between said window and said indicia;

fourth means, including transmitter means connected to and rotatable in unison with said rotary structure into intermittent engagement with said cam means for actuation by the latter into driving engagement with said rotatable means whereby to intermittently connected to and movable in unison with said rotary structure to intermittently move said pointer means past some at least of said indicia;

and second pointer means visible through said window,

connected to the movable in'unison with said rotary structure past said indicia incident to rotation of the rotary structure,

whereby said second pointer means provides a visible indication of fractional portions of each complete revolution of said rotary structure and said first pointer means provides a visible indication of the number of full revolutions of displacement of said rotary structure, from a reference position.

8. A turns-indicating knob-like structure for use in rotating the adjusting shaft of an instrument requiring rotation of the shaft through a plurality of revolutions for adjustment throughout the range of the instrument, said structure comprising:

support means arranged to be secured to the instrument shaft for rotative movements in unison with that shaft and including shell-like means simulating the surface of a knob and having a window at an end thereof;

resilient transmitter means secured to said support means for rotation therewith along a generally circular first path and movable relative thereto from said first path into a circular path;

stationary means, including means mechanically connected to said support means and presenting cam means disposed in at least part of the said first path whereby the transmitter is moved into contact therewith and is forced tomove from the said first path into and along the said second path and return,

and said stationary means comprising an indiciabearing dial visible through said Window; and

rotatable means including a structure having a pointer rotatable closely adjacent the indicia on said dial and having a series of projections each movable along said second path into position to be engaged by said transmitter means incident to movement of the transmitter from said first path into and along said second path,

whereby incident to rotation of said support means said rotatable means is intermittently rotated to move said pointer in stepwise movements past in dicia on said dial to provide a visible indication of the number of revolutions through which said support means and the instrument shaft have been rotated from a zero position.

9. A turns-indicating knob-like structure according to claim 8, including a second indicator in the form of an outer second pointer, secured to said support means to rotate in unison therewith and having a portion thereof rotatable in front of and past said indicia behind said window, whereby said second indicator provides an indication of fractional parts of a revolution through which said support means has been rotated from each of initial positions.

10. A turns-indicating knob-like structure according to claim 8, said transmitter means comprising a resilient reed secured to said support means and having an end portion free to bend radially and a ball rotatable on the free end and disposed for engagement by said cam means and movable thereby into engagement with successive ones of said projections.

11. A turns-indicating knob-like structure according to claim 8, said stationary means comprising a sleeve-like cylindrical structure having a longitudinally-serrated ext'erior surface around a portion of the periphery thereof, said support means comprising on said shell-like means a similar longitudinally-serrated exterior surface around a portion of the periphery thereof and coaxial with the serrated exterior surface of said stationary means,

and a band device encircling and complementary with either of said serrated surfaces and closely engaging one thereof and movable into concurrent engagement with both thereof whereby to releasably lock said support means to said stationary means.

12. A device for use in effecting rotation of the adjusting shaft of a shaft-adjusted instrument whose operating range is covered by a plurality of revolutions of the adjusting shaft commencing at an initial rotational position, said shaft having an outer end and an axis of rotation and said device indicating during rotation the extent of rotation of the shaft from said position in terms of full revolutions and fraction of a revolution and comprisfirst means, including support means adapted for mounting upon the adjusting shaft of the instrument for rotation in unison therewith about the axis of rotation of the shaft, said first means including hollow shell means adapted for manual rotation about said axis and providing at least an annular window at an end thereof outwardly of the end of the instrument shaft, and said first means including an outer indicator device rotatable in unison therewith about said axis and visible through said annular window;

second means, including stationary means mechanically connected to said first means and means disposed at least in part within said hollow shell means and supporting cam means disposed in a first generally circular path coaxial with said axis and supporting an indicia-bearing means visible through said window;

third means, comprising rotatable means mechanically connected to said first means and by one of said first and second means for rotation about said axis whereby said inner and outer indicator devices cogenerally between said shell means and said support operate with said indicia-bearing means to provide means, said rotatable means comprising a circular a visible indication of the extent of rotation of said set of spaced-apart teeth disposed in a second cirfirst means from an initial position.

cular path and an inner indicator device rotatable 5 13. A device according to claim 13, said stationary in unison therewith adjacent the face of said indiciameans comprising resilient detent means effective to bearing means; and yieldingly restrain said rotatable means against rotation fourth means, comprising transmitter means supported incident to absence of said transmitter from said second by said first means and rotatable in unison therepath, whereby to hold said second indicator device stawith along at least a part of said first circular path, 10 tionary relative to said indicia-bearing means between said transmitter means comprising a resilient transstepwise movements of said second indicator device.

mitter deflected out of said path and into driving engagement with one of said teeth by aid cam References Cited in the file Of this patent means incident to rotation of said transmitter into UNITED STATES PATENTS $122525;isaarsstazttaass;212a: 15

New 7,

2,746,417 McCord et al May 22, 1956 to said rotatable means,

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 151 ,598 October 6, 1964 Marlan E. Bourns et al.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 64 for "manner' read member column 6 lines 72 and 73,, for movement" read M movements line 73, for "betwen" read between 3 column 7 line 4 for "to" read l:-.= into line 30 before "annular" insert an r line 43 for "connected to and movable in unison with" read rotate the latter incident to rotation of same column 7 line 69, after "cirular" insert second column 8 line 75 after "and" insert supported column '10 line 5 for the claim reference numeral "13" read 12 Signed and sealed this 9th day of February 1965a (SE-AL) Atte'st:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 3 151598 October 6, 1964 Marlan E. Bourns et al.

It is hereby certified that error appears in the above numbered patent reqiiring correction and that the said Letters Patentshould read as corrected below.

Column 3 line 64L for "manner" read member column 6 lines 72 and 73 for movement read movements line 73, for "betwen" read between column 7 line l for "to" read e-a into line 30 before "annular" insert ane line 43 for connected to and movable in unison with" read rotate the latter incident to rotation of same column 7 line 69, after "cirular" insert second column 8 line 75 after "and" insert supported column lO line 5 for the claim refer-r enoe numeral "13" read 12 Signed and sealed this 9th day of February 1965,

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents

Claims

1. FOR AN INSTRUMENT HAVING AN ADJUSTING SHAFT ROTATABLE THROUGH A PLURALITY OF REVOLUTIONS IN EFFECTING ADJUSTMENT OF THE INSTRUMENT THROUGHOUT ITS ADJUSTMENT RANGE, A TURNSINDICATING KNOB STRUCTURE COMPRISING: FIRST MEANS, INCLUDING A SUPPORT DEVICE HAVING A BORE ALONG AN AXIS AND ADAPTED FOR MOUNTING UPON THE INSTRUMENT SHAFT COAXIALLY WITH THE SHAFT, SAID DEVICE INCLUDING MEANS TO SECURE THE SUPPORT DEVICE TO THE SHAFT FOR POSITIVE ROTATION IN UNISON WITH THE SHAFT ABOUT THE AXIS THEREOF; SECOND MEANS, COMPRISING ROTARY MEANS SECURED TO SAID SUPPORT DEVICE AND PROVIDING A KNOB-LIKE EXTERIOR ADAPTED TO BE MANUALLY ROTATED FOR ROTATION OF SAID SUPPORT DEVICE AND THE INSTRUMENT SHAFT, SAID ROTARY MEANS COMPRISING A TRANSPARENT WINDOW DISPOSED TRANSVERSELY OF SAID AXIS AND PROVIDING AN OUTER END FACE FOR THE ROTARY MEANS, SAID ROTARY MEANS BEARING AN OUTER INDICATOR MOVABLE IN UNISON THEREWITH AND VISIBLE THROUGH SAID TRANSPARENT WINDOW; THIRD MEANS, INCLUDING STATIONARY MEANS ENCIRCLING AT LEAST A PORTION OF SAID SUPPORT MEANS AND HAVING