US3635395A

US3635395A - Planetary conversion counter

Info

Publication number: US3635395A
Application number: US3347A
Authority: US
Inventors: David F Walsh
Original assignee: MELLAND GEAR AND INSTR CO Inc
Current assignee: MELLAND GEAR AND INSTR CO Inc; MELLAND GEAR AND INSTRUMENT CO Inc
Priority date: 1970-01-16
Filing date: 1970-01-16
Publication date: 1972-01-18
Anticipated expiration: 1989-01-18

Abstract

A first and a second counter are provided. Each counter has at least one rotatable readout wheel. Drive means are provided for rotating the readout wheels. Internal planetary gearing is provided between the counters. The drive means causes the readout wheel of one counter to rotate at a predetermined race relative to and different from that of the readout wheel of the other counter. An externally driven revolvable mask may be disposed over the face of the numbers on the rotatable readout wheels of the counters. The mask when revolved in one direction exposes only the numbers of one counter and when revolved in counter direction exposes only the numbers on the other counter.

Description

Unite States Patent Walsh 1 1 Jan. 18, 1972 54] PLANETARY CONVERSION COUNTER OTHER PUBLlCATlONS [72] Inventor: David F. Walsh, Lake Ronkonkoma, NY. Oberg, Erik and n F- n y 8 Handbook-16th Edition, Second Printing, Industrial-Press, 1959, pp. 837- 840. [73] Asslgnee: Mellaud Gear and Instrument Co., Inc.

[22] Filed: Jan. 16, 1970 Primary Examiner -Richard B. Wilkinson Assistant Examiner-Stanley A. Wal PP N04 3 At!0meyI-Iarry C. Bierman, Jordan B. Bierman and Bierman & Bierman [52] US. Cl. ..235/l A, 235/117 R, 235/139 A 51 1m. 01 .006: 27/00 I [571 ABSTRACT Field of Search 35/ 1 17 1 l 91 P A first and a second counter are provided, Each counter has at 235/91 11,61 139 A, 103 least one rotatable readout wheel. Drive means are provided for rotating the readout wheels. lntemal planetary gearing is References cued provided between the counters. The drive means causes the readout wheel of one counter to rotate at a predetermined UNITED STATES PATENTS race relative to and different from that of the readout wheel of 2,753,116 7 1956 Manke ..235 139 A the other eounter- An externally driven revolvable mask y 2,532,970 12/1950 Van Dyke,- ....235/l03 X be disposed over the face of the numbers on the rotatable 1,325,911 12/1919 Rhoades ....235 103 x readout wheels of the eounters- The mask when revolved in 2,661,903 12/1953 Goldbach ....235/117 R one direetion exposes y the numbers of one eounter and 2,851,215 9/1958 Bliss et a1 ..235/1 A when revolved in counter direction exposes only the numbers 3,010,652 11/1961 Heuver et al.. ....235/117 R on the other women 3,229,907 H1966 Shatas et al. ..235/1 17 R 10 Claims, 6 Drawing Figures .FOREIGN PATENTS OR APPLICATIONS 27,699 12/1930 Australia ..235/1A PLANETARY CONVERSION COUNTER This invention relates to conversion counters. More particularly, it relates-to a conversion counter which employs internal planetary gearing, which gearing provides the required ratio between, for example, a digital readout of inches of mercury and a digital readout of millibars in an altimeter.

In certain altimeters of the prior art, conventional barometric counters are comprised of two four-digit counters. Each of the counters is separately mounted into the altimeter. The counters are connected through separate external gear trains, the gear train ratio being designated by the ratio of inches of mercury to millibars is approximately 2.9375 to 1.

Due to the density of the instrument package, counting devices intended for airborne application must of necessity be miniaturized.

It is an object of this invention to provide a dual counter assembly having internal planetary gearing. The internal planetary gearing provides the required ratio between the counters. The dual counter assembly of the present invention can .be mounted on a single mounting bracket.

A further object of this invention is to provide a dual counter assembly which canbe more readily miniaturized and which has greater reliability than the counters of the prior art.

It is still another object of this invention to provide a dual counter assembly which, due to its fewer parts and ease of assembly, is considerably less expensive than counters of the prior art.

In the conventional counter of the present invention theinternal gearing lies within the diameter of the counter wheel. More particularly, it is disposed within the area between the counters. This eliminates the necessity of the gearing, bearings and bearing-mounts which were required in prior art devices for driving the individual counters and the altimeter.

The planetary conversion counter of the present invention affords several important advantages as compared with the counters of the prior art. First, the counter of the present invention utilizes fewer components. Second, it occupies less space in the instrument package, and, third, due to its decreased number of components and ease of assembly, as recited heretofore, it permits substantial cost savings.

It is obvious that a single input component which serves a dual purpose would be easier to design into an instrument package as compared with two separate components having separate driving mechanisms.

The present invention will be explained with reference to the following drawings wherein:

FIG. 1 is a front plan view of a planetary conversion counter of the present invention, showing the shuttering arrangement of the present invention,

FIG. 2 is a cross-sectional view of the planetary conversion counter of FIG. 1, V

FIG. 3 is a cross-sectional view of the planetary conversion counter of FIG. 2 taken along the line 3-3 looking in the direction of the arrows,

FIG. 4 is a perspective view of the shuttering arrangement,

FIG. 5 is a side view of the shuttering arrangement of FIG. 4, and

FIG. 6 is a front view of the counter of FIG. 1 showing the counter mounted within a housing having a window which cooperates with the shuttering arrangement of FIG. 1.

It should be noted that these figures are offered only for the purpose of illustrating the planetary conversion counter of the present invention and not for the purpose of limiting same.

The mounting bracket 4 has an upright portion 6 and a base portion 7. The first counter I comprisesa barrel 8 having a rear plate 9. Barrel 8 is mounted on the. upright portion 6 of the mounting bracket 4, with two screws. A first pinion transfer 11, a second pinion transfer 12,,and a third pinion transfer 13 are each mounted for rotation about pinion shaft 14. Pinion shaft 14 is fixed at one end in the upright portion-6 of the support 7 and fixed at the other endiin plate 9. Shaft 10 is mounted for rotation in

bearing sleeves

20 and 21. A unit wheel 15, a first middle wheel.l6, a second middle wheel 17, and an end wheel 18 are each mounted for rotation about the barrel 8. A drive disc 19 is mounted for rotation with the shaft 10 so that the unit wheel 15 makes one 360 rotation with each 360 rotation of the shaft 10. Unit wheel 15 is mounted for rotation with drive disc 19. The unit wheel 15 can be integral with drive disc 19. Alternatively, drive disc 19 can be press fit into unit wheel 15. Preferably, the unit wheel l5.is bonded to drive disc 19 with, for example, an epoxy resin. Upon rotation of the shaft 10 the unit wheel 15 turns 324.and engages the first pinion transfer 11 which then turns the first middle wheel 16 at the same rate as the unit wheel 15 for 36, at which point the second pinion transfer 12 engages the second middlewheel l7 and turns it at the same rate as the unitwheel 15 and the first middle wheel 16 for 36; whereupon the third pinion transfer 13 engages the end wheel 18 and turns it at the same rate as the unit wheel .15, the first middle wheel 16 and the second middle wheel 17. Thus, when the shaft 10 has made 1,000 full rotations, the unit wheel 15, the

first middle wheel 16, the second middle wheel 17, and the end wheel 18 will have, respectively, made 100, 10, and l rotations.

A drive or sun gear 22 is mounted and fixed on shaft 10 so that for each complete rotation of the shaft 10 the drive gear rotates once. A stationary fixed or annular gear 23 is mounted on upright 6. An idler or planet gear 24is fixed to the unit wheel 15 of the second counter 2. It should be noted that though only one idler or planet gear isrequired, more than one idler gear can be employed. Drive gear 22 engages idler gear 24 which in turn is engaged with fixed gear 23.

As shown in FIG. 3, as shaft 10 rotates, drive gear 22 rotates with it and rotates the idler gear 24 around the inside of the fixed gear 23. Since the idler gear 24 is fixed to'the unit wheel 15', the unit wheel 15' rotates with the idler gear 24. When the unit wheel 15' turns 324 it engagesa first pinion transfer 11' which then turns the first middle wheel 16 at the same rate'as the unit wheel 15' for 36, at which point the second pinion transfer 12' engages the second middle wheel 17' and turns it at the same rate as the unit wheel 15' and the first middle wheel 16 for 36 whereupon the third pinion transfer 13 engages the end wheel 18 and turns it at the same rate as the unit wheel 15', the first middle wheel 16' and the second middle wheel 17'.

It is obvious that the conversion ratio desired determines the ratio of the internal planetary gearing of the conversion counter of the present invention. For example, to convert inches of mercury to millibars, a 2.9375 gearing ratio of the planetary gearing is required. In the counter of the present invention this ratio is readily obtained by employing a drive gear having 32 teeth and a fixed gear having 62 teeth. As a further example, the counter of the present invention can be utilized to convert quarts to gallons. Since there are 4 quarts to 1 gallon, a 4:1 gear ratio is required. This is attained by utilizing a fixed gear having teeth and a drive gear having 30 teeth. It is obvious that countless other conversions can be carried out with the conversion counter of the present invention.

In the conversion counter of the present invention the shaft 10, as stated heretofore, is mounted for rotation in bearing

sleeves

20 and 21. Shaft 10 is additionally mounted in bearing sleeves 20' and 21'. Thus the conversion counter of the present invention can be driven from either end of shaft 10.

Advantageously, as shown in FIG. 1, an externally driven, revolvable shuttering arrangement (mask) 25 is mounted for rotation on shaft 10 and disposed over theface of the numbers on the rotatable wheels of the counters so that, as shown in FIG. 5, when revolved in one direction only the numbers of counter 1 are exposed, and when revolved in counterdirection only the numbers on counter 2 are exposed. This eliminates the possibility of confusion between the reading on counter l and the corresponding reading on counter 2.

As shown in FIG. 4 the mask 25 is comprised of a first masking strip 26, a second masking strip 27 fixed to the first strip 26, a first bracket member 28 and a second bracket member 29. Bracket member 28 has a flange portion 30 adapted to cooperate with driving means for rotating the mask. Each bracket member has a hole 31 which is utilized for mounting the mask 25 on shaft 10. The first masking strip 26 is angularly offset from the second masking strip 27 in one direction, and the second masking strip 27 is angularly offset from the first masking strip 26 in the other direction.

As shown in FIG. 5, the mask 25 is rotatable between two positions. In the first position the numbers of counter l are exposed while the numbers of counter 2 are masked. In the second position, as shown in FIG. 1, the numbers of counter 2 are exposed while the numbers of counter l are masked.

As shown in FIG. 6, the conversion counter of the present invention can be mounted in, for example, a housing. The front plate 32 of the housing has a window 33 through which the numbers of one line of counter 1 and one line of counter 2 are visible. The mask 25 cooperates with window 33 so that the numbers of only one of said lines is visible at any one time.

It is obvious this conversion mechanism can be incorporated with other type counters using external pinion or internal pinion transfer gearing.

1 claim:

1. A conversion counter comprising a first counter having at least one rotatable calibrated readout wheel, a second counter having at least another one rotatable calibrated readout wheel, drive means for rotating said one wheel and said another wheel, and internal planetary gearing between said first counter and said second counter whereby said drive means causes said another wheel to rotate at a predetermined rate relative to and different from that of said one wheel, and means for selectively masking one of said one wheel and said another wheel, the other one being exposed, said means for masking comprising a rotatable mask disposed over said one wheel and said another wheel, said mask being rotatable with respect to said wheels, and drive means for rotating said mask in one direction to expose one of said wheels while masking the other one of said wheels, and in counterdirection to expose the other one of said wheels while masking said one of said wheels.

2. A conversion counter comprising a first counter having at least one rotatable calibrated readout wheel, a second counter having at least another one rotatable calibrated readout wheel, drive means for rotating said one wheel and said another wheel, and internal planetary gearing between said first counter and said second counter whereby said drive means causes said another wheel to rotate at a predetermined rate relative to and different from that of said one wheel, said drive means is a single shaft, said planetary gearing comprises a stationary annular gear, a sun gear mounted and fixed on the shaft, at least one planet gear connected to said another wheel and engaged with the annular gear and the sun gear, whereby rotation of the shaft causes the planet gear to rotate in a circular path around the sun gear and the rotation of the planet gear causes rotation of said another wheel, and means for selectively masking one of said one wheel and said another wheel, the other one being exposed, said means for masking comprises a rotatable mask disposed over said one wheel and said another wheel, said mask being rotatable with respect to said wheels, and drive means for rotating said mask in one direction to expose one of said wheels while masking the other one of said wheels, and in counterdirection to expose the other one of said wheels while masking said one of said wheels.

3. A conversion counter as described in claim 1 wherein said mask comprises a first masking strip and a second masking strip, said first strip being angularly offset from said second strip in one direction, said second strip being angularly offset from said first strip in the other direction.

4. A conversion counter as described in claim 2 wherein said mask comprises a first masking strip and a second masking strip, said first strip being angularly offset from said second strip in one direction, said second strip being angularly offset from said first strip in the other direction.

5. A conversion counter as described in claim 3 wherein said first and second masking strips are arcuate.

6. A conversion counter as described in claim 4 wherein said first and second masking strips are arcuate.

7. A conversion counter as described in claim 1 wherein said mask is rotatable between a first position and a second position whereby when said mask is rotated to the first position one of said wheels is exposed and the other one of said wheels is masked, and when said mask is rotated to the second position the other one of said wheels is exposed while said one of said wheels is masked.

8. A conversion counter as described in claim 2 wherein said mask is rotatable between a first position and a second position whereby when said mask is rotated to the first position one of said wheels is exposed and the other one of said wheels is masked, and when said mask is rotated to the second position the other one of said wheels is exposed while said one of said wheels is masked.

9. A conversion counter as described in claim 7 further including a housing having a window, said first and second counters being disposed within said housing so that the calibrations on only one line of said wheels are visible through the window, the mask cooperating with the window so that the calibrations of only one line of one of said wheels is visible at any one time through the window.

10. A conversion counter as described in claim 8 further including a housing having a window, said first and second counters being disposed within said housing so that the calibrations on only one line of said wheels are visible through the window, the mask cooperating with the window so that the calibrations of only one line of one of said wheels is visible at any one time through the window.