US2712413A - Multi-stage revolution counter - Google Patents

Description

July 5, 1955 A. F. HAYEK 2,712,413

MULTI-STAGE REVOLUTION COUNTER Filed Aug. 25, l955 2 Sheets-Sheet 1 3 :1 L 66 42 M a L. 64

g0 Eh IN VEN TOR. ARTHUR 5 HAYEK AT RNEY y 5, 1955 A. F. HAYEK MULTI-STAGE REVOLUTION COUNTER 2 Sheets-Sheet 2 Filed Aug. 25, 1953 Tic E.

O 23456789O 23456789 98765432 O987654 2 0 INVENTOR.

ARTHUR F. HAYEK 723i;

ATTORNEY MULTl-STAGE nnvorurroiv COUNTER Arthur F. l-llayek, Pieasantville, N. Y., assignor to General Pecision Laboratory Incorporated, a corporation of New York Application August 25, 2953, Serial No. 376,433

3 Claims. (U. 235-1) This invention relates to a revolution counter which will indicate either an increasing or decreasing quantity with the same direction of input shaft rotation and more particularly to such a counter which will operate satisfactorily at high speeds.

Multi-stage revolution counters are well known in the art, one common type comprising several cylindrical drums each bearing a row of figures around its periphery. The counter is provided with a cover having one or more windows through which the proper numbers are visible. The lowest stage drum is continuously driven by the input shaft and periodically indexes the next higher stage drum which, in turn, indexes the next succeeding stage drum and so on. The indexing is usually accomplished by means of a mutilated gear which engages a pinion connected to the next higher stage drum. Such counters are quite satisfactory as long as they are operated at a relatively low speed.

It is sometimes desired to rotate a counter at high speed in order to reset the counter to zero, or to some other predetermined position. it has been found that counters as above described are subject to frequent mechanical failure when rotated at high speed. This is because the mutilated gear which is moving at high speed suddenly makes contact with the stationary pinion which must be accelerated at once to the speed of the moving gear. The resulting forces are often too great for the mechanism to withstand.

A counter may also be designed to indicate either an increasing or a decreasing quantity with the same direction of input shaft rotation and is useful for indicating deviations to the right or left of a reference direction, or for indicating degrees and minutes of longitude or latitude. Such a counter may comprise either two separate counters or a single counter, each drum of which bears two sets of digits, one increasing in one direction and the other increasing in the opposite direction. Either arrangement requires the last stage to index a shield or mask which conceals one set of digits from view while exposing the other set. Such a counter is even more dilficult to operate satisfactorily at high speeds because the mask must be accelerated at the moment when all the other moving parts of the counter are being accelerated. This results in a considerable strain on all the moving parts and also requires a large increase in the power drawn from the input shaft.

A counter with a double row of figures on each drum also presents an indexing and indication problem. If the lowest number on one row is aligned with the highest number on the other row (e. g., zero aligned with nine), the counter will either gain or lose one unit when passing through zero or its maximum indication. if the two lowest numbers are aligned (e. g., zero aligned with zero), the counter will indicate correctly when passing through zero or its maximum, but will present an ambiguous indication each time the unit, or fastest moving, stage indexes the succeeding stage.

It is an object of this invention to provide a multi-stage H of the invention which is useful Patented July 5, 1955 revolution counter which will operate satisfactorily at high speed.

Another object of this invention is to provide a multistage revolution counter requiring only a small increase in the power drawn from the input shaft during periods of indexing.

Another object of this invention is to provide a multistage revolution counter capable of indicating either an increasing or decreasing quantity with the same direc tion of input shaft rotation.

A further ObJCCt of this invention is to provide a multistage revolution counter for indicating both increasing and decreasing quantities which will yield correct and unambiguous indications both when passing through zero and during other periods of indexing.

A preferred embodiment of this invention comprises a plurality of cylindrical drums each bearing two sets of digits on its periphery, one increasing in one direction and the other increasing in the opposite direction. The first drum is continuously driven by the input shaft and indexes the second drum by means of a Geneva type of intermittent movement. Each succeeding drum is indexed by the next preceding drum by means of a conventional mutilated gear arrangement. A mask is provided having two groups of apertures arranged to selectively expose one or the other set of digits on each drum. The mask is indexed by the highest order drum through an eccentric pin and slotted lever movement. The Geneva movement and the slotted lever movement cooperate to reduce the forces due to acceleration during periods of indexing to such an extent that the counter may be operated satisfactorily at high speeds.

To overcome the indexing and indication problem, the first drum is inscribed with two rows of index lines. A digit is inscribed adjacent to each line. The digits in one row increase in one direction, while the digits in the other row increase in the opposite direction. The two index lines corresponding to zero on each row are aligned. However, the digits are not exactly aligned with their corresponding index lines, but are displaced slightly, the digits of one row being displaced in one direction while the digits in the other row are displaced in the opposite direction. The indexing motion of the succeeding drum is centered about the zero index line. By this arrangement, the counter will neither lose nor gain a unit when passing through zero and the ambiguity during indexing is virtually eliminated.

For a more complete understanding of the invention reference may be made to the accompanying drawing in which:

Figure 1 is a View of place;

Figure 2 is a rear elevation view with the cover removed and the mask broken away;

Figures 3, 4, 5, 6 and 7 are the lines 3-3, 4 4, 'o"-5, 6 of Fig. 2;

Figure 8 is a developed view of the indicating drums showing the arrangement of the digits and index lines thereon;

Figure 9 is a view of the mask; and

Figure 10 is a series of views useful in explaining the operation of the counter.

Fig. l is a general view of a preferred embodiment in connection with navigational equipment for continuously indicating the de grees and minutes of longitude of a vessel it travels over the high seas. In the position shown in the figure, the set of digits on each drum which indicate west tough tude are exposed. if a vessel were to travel from the position indicated eastward, the indicati is would continuously decrease until the zero meridian were reached the counter with the cover in sectional views taken along -6 and '7-7, respectively,

3 at which point the mask would expose the other set of digits. As the vessel continued to travel eastward, the indications would continuously increase until the 180th meridian were reached at which point the mask would be moved so as to expose the first set of digits.

The invention will be described principally with reference to Fig. 2 with occasional reference to the other figures.

Referring now to Fig. 2, there is shown a base 11 to which are secured two uprights 12 and 13 which serve to support the entire counter mechanism. A main shaft 14 and a jack shaft 15 are supported by uprights 12 and 13 so as to be freely rotatable. The shaft 14 carries two supports 22 and 23 for the mask and also five indicating drums 16, 17, 18, 19 and 20, the drum 16 being secured to the shaft 14 while the remaining drums are freely rotatable thereon.

As shown in Fig. 8, the drum 16 bears two rows of digits and index lines, each row of digits running from zero to nine twice. Rotation from one full line to the next fuil line represents one minute of longitude, and each revolution of the drum 16 represents twenty minutes of longitude. Drum 17 indicates tens of minutes of longitude and bears two rows of digits each running from zero to live three times. It is apparent that drum 16 should index drum 17 twice per revolution and that each index should advance drum 17 by twenty angular degrees. Drum 18 indicates units of degrees and bears two rows of digits each running from zero to nine twice.

Drum 17 should index drum 18 three times per revolution, each index advancing drum 18 by eighteen angular degrees. Drum 19 indicates tens of degrees and bears two rows of digits each running from zero to seven and from Zero to nine. Drum 18 must index drum 19 twice per revolution, each index advancing drum 19 by twenty angular degrees. Drum 20 indicates hundreds of degrees and is secured to drum 19 so as to be rotatable therewith. Drums 19 and 20 could be combined in a single drum but have been made separate for convenience in manufacture and for improved appearance of the completed counter.

Referring again to Fig. 2, there is secured to shaft 14 a disk member 24 which has two raised arcuate portions 25 and 26, as best shown in Fig. 3. Member 24 also carries two pins 27 and 28. A star wheel 29 having six slots is secured to a stub shaft which is carried by the upright 12. The locations of shafts 14 and 30 and the diameters of the member 24 and the star wheel 29 are selected so that pins 27 and 28 will enter and leave the slots of the star wheel tangentially. By this arrangement the star wheel 29 will be rotated through sixty degrees twice during each revolution of shaft 14 and will be accelerated gradually from rest to an angular velocity equal to that of shaft 14 and will then be decelerated to zero angular velocity.

The arcuate portions 25 and 26 of the member 24 bear on corresponding arcuate portions of the star wheel .29 to prevent wheel 29 from rotating except when one of the pins 27 or 28 is in one of the slots.

Also secured to the stub shaft 30 is a gear 32 which meshes with an idler gear 33 supported by a stub shaft 34. A gear 35 meshes with gear 33 and is mounted to be freely rotatable on the jack shaft 15. A sleeve 36 is provided to keep gear 35 spaced from upright 12. Gear 35 is fastened to, or made integral with, a sleeve 37 (best shown in Fig. 2) which is also integral with a gear 38. The gear 38 meshes with a gear 39 which is mounted so as to be freely rotatable on shaft 14. Indicating drum 17 is secured to the gear 39. The number of teeth on each of the gears 32, 33, 35, 38 and 39 is selected so that each time the star wheel 29 is advanced by sixty degrees, the drum 17 will be advanced by twenty angular degrees.

The drum 17 indexes the drum 18 three times in each revolution by means of a locking ring 41, a mutilated gear 42, a pinion 43, and a gear wheel 44. The locking ring 41 and the mutilated gear 42 are fastened to the drum 1'7 to rotate therewith. The pinion 43 is mounted on the jack shaft 15 and has a sleeve 45 integral therewith for spacing the gear -9-3 from the pinion 38. Pinion 43 has four teeth throughout one portion of its length and eight teeth throughout the remaining portion of its length. The locking ring 41 is a cylindrical member having three indentations 46, 47 and 48 as shown in Fig. 5, and engages the pinion 43 on that portion of pinion 43 where it has only four teeth. This arrangement prevents the pinion 43 from turning except when one of the indentations is opposite one of the teeth of pinion 43. The mutilated gear 42 has three pairs of teeth 51, 52 and 53 spaced 120 degrees around its periphery in alignment with the indentations on ring 41. These pairs of teeth are arranged to intermittently engage the pinion 43 on the portion of its length where it has eig it teeth, as shown in Fig. 6. It can be seen that three times during each revolution of the drum 17, the locking ring 41 will unlock the pinion 43 and allow the gear .2 to index the pinion 43. The rotation of pinion 43 is transferred to the indicating drum 18 by means of the gear 44 which is secured to the drum 18.

Twice during each revolution of the drum 13, the drum 19 is indexed through another set of gears comprising a locking ring 54, a mutilated gear 55, a pinion 56 and a gear wheel 57. This gear train is similar to that above described except that the locking ring 54 has but two indentations and the mutilated gear 55 has but two pairs of teeth. As a result, the drum 19 is indexed twice per revolution of the drum 18. The drums 19 and 20 are fastened together so as to rotate in unison.

The apparatus so far described will indicate only an increasing quantity, or a decreasing quantity, but will not indicate both. In order to provide for both increasing and decreasing indications, a mask is provided to selectively expose one or the other set of digits on the indicating drums. The mask must be indexed once during each revolution of drums 19 and 2d, at the same moment that all the other drums are being indexed. It has been found that the additional load imposed upon the mechanism makes it necessary to still further reduce the forces of acceleration arising when the mask is indexed. This is accomplished by means of a second mechanical arrangement which accelerates the mask gradually.

Secured to the drums 19 and 20 is a locking ring 58 and a mutilated gear 59 which cooperate with a pinion 60 in the same manner as that described in connection with ring 41, mutilated gear 42 and pinion 4-3. The ring 5 3 has one indentation and the gear 59 has one pair of teeth, so that the pinion 60 is indexed once for each revolution of drums 19 and 20. A sleeve 62 is placed on the jack shaft 15 to space the pinion 60 from the pinion 56. A sleeve 63 is secured to pinion 6t) and is also secured to a gear 64. A gear 65 meshes with gear 64 and is supported on upright 13 by means of a stub shaft 66. Also secured to stub shaft 66 is a cylindrical member or disc 67 carrying an eccentric pin 68.

As best shown in Fig. 4, the mask support 23 is pivoted on shaft 14 and has a depending portion 69 with a slot 71 cut therein which engages the eccentric pin 68. The various gear ratios are selected so that when the drums 19 and 20 are indexed through 20 degrees, the disc 67 will be rotated degrees. This rotation will cause the support 23 to be gradually accelerated and then decelerated while going through an angular movement of approximately thirty-six degrees.

Y When assembled for operation, the mask 72 shown in rig. 9 is secured to the supports 22 and 23 so as to conceal one row of digits while exposing two digits on each drum in the other row. As the input shaft 14 is rotated, the star wheel 29 will be gradually accelerated, since the pins 27 and 28 enter and leave the slots tangentially. This gradual acceleration will be transmitted to all of the other moving parts of the counter so that indexing is accomplished with substantially no impact. Gnce during each revolution of dr 'ns 2111C. the mutilated gear 59 will engage the pinio W and, ough gears 5 5 and 65, cause the disc 67 (see Fig. 4) to hrough one half a revolution. t the start 0 'on, the pin 6? will be travelling substanti ly i y along the slot 71 so that the mask sup e gradually accelerated and then gradually decel The entire indexing op eration, including the shining of the mask 1 2, is accomplished smoothly and without any stresses caused by the impact of a moving part upon a stationary part.

in constructing a counter as so described, consideration must be given to arrangement of digits on the fastest moving, or units, drum and to the position of this drum when it indexes the next drum. Consider first a unit drum bearing two rows of digits running from zero to nine in opposite directions, with the Zero of each row aligned with the nine of the opposite row. Drum 18 of Fig. 8 illustrates such an arrangement. 'l'he indexing movement should be centered half way between the nine and the zero. 'lthis will result in proper indexing whether the left or right row of digits is exposed by the mask. But such an arrangement will cause a loss of one unit when passing through zero. Suppose that the mask is exposing the right hand row of digits and that the shaft is rotated so as to decrease the indication. When the counter reaches the digit one, an additional rotation of one unit will cause the counter to read zero. A further rotation of one unit should cause the counter to read one in the opposite direction, but at this moment the mask will conceal the ri hand row of digits and expose the figure zero on the lert hand row. The shaft has advanced by one unit, but the counter still indicates zero.

Consider next a fastest moving, or units, drum bearing two rows of digits running from zero to nine in opposite directions, in which the zeros of the two rows are aligned. T he location of the point half way between zero and nine on the right hand row is not the same as the location of the corresponding point on the left hand row and therefore the indexing movement must be centered about the center line of the zeros. Suppose that the mask is exposing the right hand row of digits and that the shaft is rotated so as to decrease the indication. When the counter indicates one, an additional shaft rotation corresponding to one unit will bring the zero of both rows into position and start to index the mask. A further shaft rotation of one unit will complete the index of the mask and expose the digit one on the left hand row. Thus it is seen that this arrangement produces correct indications when pass ing through zero. However, this arrangement of digits causes an ambiguity of indication each time the units drum indexes the tens drum. in Fig. 10, a is a view of such a counter indicating the quantity 39. As the input shaft is rotated the unit drum will start to index the tens drum, and when the unit drum has reached zero, one half of the indexing movement will have been completed. As shown in b of Fig. 10, it is not clear whether the indication is thirty or forty. When the drum has reached one, the indexing movement will have been completed, and the counter will indicate forty one, as shown in c of Fig. 10.

The invention overcomes the foregoing diliiculty by the arrangement shown in Fig. The index lines on the two rows are aligned, but the digits are displaced slightly. The center line of each digit is displaced by one quarter of the unit distance toward the index line corresponding to the next higher digit. Each digit on the right hand row is displaced downward as shown in Fig. 8, while each digit of the left hand row is displaced upward. The in dex lines for the two zeros are aligned, and the indexing motion is centered about these lines. The effect of this arrangement is shown in d, e and f of Fig. 10. In d, the digit nine is not exactly in line with the digit three, but the indication is clearly thirty-nine. In e, the zero is more nearly aligned with the four than with the three so that the indication is forty. At first glance there may be some doubt as to whether the indication is thirty-nine or forty or something between the t o. This uncertainty is far less serious than that shown in b of Fig. 10, where the un certainty is whether the indication is thirty or forty. Furthermore, reference to the index line shows that the indication is in fact forty and not thirty-nine. Further rotation of the unit drum completes the indexing of the tens drum, maxing the indication forty-one as shown in f of Fig. 10.

invention has been described by reference to a preterred embodiment. However, many modifications may be made within the scope of the invention. For example, instead of using cylindrical indicating drums, two sets of indicia could be placed upon a series of discs. As another example, the indicia and gear ratios may be selected so as to indicate latitude, to indicate deviations to the rigl" and left of a reference direction, or to indicate positive and negative quantities with respect to a selected reference. Many other modifications will occur to those skilled in the art.

What is claimed is:

1. A multi-stage revolution counter comprising, a plurality of rotary members each inscribed with double row of indicia, means for selectively exposing one or the other row of indicia on each member, an input shaft for continuously driving the fastest moving member, the indicia on said fastest moving member including a row of index lines about one of which the next fastest moving member is periodically indexed and a figure adjacent to each in ex line, the center line of each figure being oifset from its corresponding index line.

2. A multi-stage revolution counter comprising, a pluraiity of rotary members each inscribed with a double row of indicia, means for selectively exposing or the other row of indicia on each member, an input shaft for continuously driving the fastest moving member, the indicia on said fastest moving member including double row of index lines about one of which the next fastest moving member is periodically indexed, each line of one row being spaced from axially aligned with a line on the other row, and a figure adjacent to each index line, the center line of each figure being oifset from its corresponding index line.

3. In a multistage revolution counter which comprises a pluraiity of rotary members each bearing two rows of indicia and having means for selectively exposing one or the other of the rows of indicia on each member, an arrangement for minimizing the ambiguities of indication during periods of indexing comprising, an input shaft for continuously rotating the fastest moving rotary member, two rows of parallel index lines on said member perpendicular to the direction of peripheral motion, the index lines of each row being spaced apart and the lines of one row being axially aligned with the lines of the other row, the distance between adjacent lines of one row corresponding to one unit to be counted, means for indexing the next fastest moving member by said fastest moving member, the indexing motion being centered about one of said index lines, and a digit beside each index line, the center line of each digit on one row being offset in one direction from its corresponding index line, and the center line of each digit on the other row being offset in the opposite direction from its corresponding index line.

Re erences titted in the file of this patent UNllED STATES PATENTS 1,542,465 Macgill June 16, 1925 1,743,562 Mombur .ian. 14, 1930 2,483,359 Bliss Sept. 27, 1949 2,605,047 Nyyssonen et al. July 29, 1952 FOREIGN PATENTS 725,713 Germany .e M Sept, 28, 1942

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