US2342325A - Counter unit mechanism - Google Patents

Description

Feb. 22, 1944. H. N. Buss 2,342,325

COUTER UNIT MECHANISI I Filed Septf 26, 1940 INVENTR HARVEY 5 d 5f 5l 45] 9G17 I ATT RNEYS Patented Feb. 22, 1944 COUNT-Ea Uma MECHANISM Harvey N. Bliss, Windsor, Conn., assigner io Voeder-Root Incorporated, Hartford, Sonn., corporation of Connecticut I Application September 2li, 194i), Serial No. 358,461 d Claims. (Ci. 235miid) The presentinvention relates to a counter unit having a numeral-Wheel,I a driven member or gear, and. a pawl and ratchet connection therebetweenwhereby during a registering4 operation l vthe driven gear and numeral wheel may he driven as a unit andduring a resetting operation the numeral wheel may be reset to a starting posi tion` without transmitting rotation of the driven gear.

Itis an object ofthe present invention to pro- I vide a counter unit of the lcharacter described, the parts of which can be easilyiormed of a moldable plastic and which is particularly characterized by its extreme simplicity of construction, economy of manufacture, ease of assembly and efficiency of operation. Y

Other objects will be inrpart obvious and in part pointed out `more in detail hereinafterc The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplined in the construction hereafter set forth and the scope of the application of which will be indicated in the appended claims.

In the accompanying drawing:

Figure l is a side elevation of the assembled counter unit;

Fig. 2 is a section through the unit taken/along the line 2-2 of Fig. 1;

Fig. 3 shows the opposite side elevation of the counter unit from that illustrated in Figure 1;

Fig. 4 is a cross-sectional view of the counter unit taken along line 4-4 of Fig. 2 and is shown with portions ofthe driven member and the bearing plate broken away so as to more clearly illustrate the reset pawl; and

Fig. 5 is an exploded view of the counter unit illustrating the driven member, the bearing plate and the counter wheel in perspective.

. Invaccordance with the present invention there is provided generally a 4counter unit comprising@ a numeral wheel having an internal ratchet wheel III formed therein, and a driven member II journalled on the hub of the numeral wheel for transmitting unidirectional rotation to the numeral wheel by means of reciprocating pawls I2 and the cooperating ratchet Il. As is customary in counter mechanisms, the numeral wheel A is roother starting position, the` shaft is rotated in the same direction as that in which the counter unit is driven for registration. The groove 9 picks up the nose portion of a spring pressed reset pawl 45, radially positioned and reciprocally car.- ried by the numeral wheel, and rotates the numeral wheel to the zero or starting position. During the resetting operation the driven member I I remains stationary and the ratchet wheel Ill formed 'in 4the numeral wheel rides over the pawls I2 of the driven member.

More specifically, the numeral wheel A is formed of plastic, as by a molding operation, and, by preference there is integrally formed therewith a mutilated driving or two-toothed gear 59 and a locking disk which are customarily provided in units of this type. As these parts are all molded into an integral unit, the expense of manufacturing is considerably reduced. The numeral wheel A further comprises a central hub I5 from which extends a disk like web I6 provided with a peripheral flange I'I. In accordance with the general practice in numeral wheels of this type, spaced numerals in consecutive relationship from 0 to 9" may be provided on the flange for registering a counting operation. The numeral wheel A also has an annular cavity I8 between hub I5 and flange I1, and as illustrated in Figs. 4 and 5, the ratchet wheel I0 is formed on the inner surface ofthe flange I1 and comprises ratchet teeth 2II spaced by notches ZI. Each tooth 20 is V shaped and is formed by a pair of obtusely disposed interconnected walls 24 and 25. The apexes of the teeth are disposed towards and equally spaced about'the axis of the wheel. The walls 24 and 25 of each tooth are symmetrical with respect to a radial line passing through the apex of the tooth and the axis of the wheel so that the wall 24 and the wall 25 of each pair of adjacent teeth form one of the V. shaped notches ZI. Formed upon the web I6 within the cavity I8 are radially extending ribs I6 and a rib Il. Referring to Figs. 2 and 5, the left hand faces of these ribs all lie in the same plane so that the spacing and retaining plate P. hereinafter described more in detail, may bear vagainst them. The rib 4l has a radially extending groove so as to provides. guideway 4B for accommodating the spring pressed reset pawl 45. TheV locking disk B0 is in the form of an annular Iiange formed integrally with, and located on the right side of the'web portion oi' the numeral wheel, as seen in Fig. 2. As previously stated, the mutilated drive or two-toothed gear 59 is also formed integrally with the wheel A.

It is understood, of course, that the two-'toothed gear 59 is adapted to cooperate with the usual transfer pinion to advance the next wheel of higher order, and the locking disk cooperates with that pinion in order to prevent it from turning except during a transfer operation. The transfer mechanism may be similar to that disclosed in the patent to Spaunburg No. 2,040,031

and needs no further description.

The driven member II of the counter unit is also preferably made of plastic material and, as herein disclosed, comprises a gear having twenty teeth II'. Integrally formed with the member yII is a disk portion II" which is of lesser diameter than the gear and is rotatably mounted in the cavity I8 of the numeral wheel on the hub I5. The aforementioned pawls I2 are carried for reciprocation in two open grooves or guideways 21 cut in the disk portion II. The guideways are preferably parallel with each other and disposed at right angles to a diameter of the driven member so that the grooves are located on chords of the disk portion Il". Each of the grooves forms an opening at one of its ends in the periphery of the disk portion II". The pawls I2 are generally rectangular in cross section to conform to the rectangular cross section of the grooves 21 in which they slide. The corner 35 of the driving end 36 of each pawl, which corner is remote from the axis of the unit, is curved so as to properly cooperate with the sloping walls of the notches 2I of the ratchet wheel in order that the camming action between the pawls and such sloping walls will tend to rotate the numeral wheel to predetermined positions relative to the driven member and thus prevent the numeral wheel from stopping in a position which is intermediate of two proper registering positions. The

location and construction of the pawls are such that when the driven member is driven counterclockwise with respect to Fig. 4, the pawls will drive the numeral wheel in a registering direction, and when the reset shaft is turned in the same direction during a resetting operation, the numeral wheel is turned therewith but the ratchet wheel ratchets over the pawls and the driven member remains stationary. The pawls are normally urged into engagement with the ratchet wheel lby coiled springs 33 located in the grooves 21 behind the pawls. In order to prevent the springs from ejecting the pawls from the grooves during the operation of assembling the unit, each groove has a lug 30 which is accommodated by a recess 34 in the opposing face of the pawl,

The reset pawl 45 is mounted for reciprocav non in the guideway 4s which is eut in the rib 41 and extends through the hub I5 of the wheel.

A spring 5I is positioned between the rear end 45 of the pawl and the rear wall 52 of the guideway 46 and normally urges the pawl forwardly into engagement with the reset shaft 9. The forward or inner end of the pawl is somewhat wedge shape and is adapted to cooperate with the reset groove 9 of the reset shaft 9. One face 55 of this groove is substantially radially disposed with respect to the axis of the shaft, and the other face or camming surface 56 of the groove is obtuse with respect to the face 55. During a registering operation, the wheel A is rotated counterclckwise (see Fig. 4) and the pawl' 45 ratchets over the groove 9 in the reset shaft 9. During a resetting operation, the drive surface 55 of the reset groove engages the opposing face of the pawl 45 and turns the wheel counterclockwise to a zero position. Simultaneously, lthe pawls I2 ratchet over the ratchet teeth 20 and the driven member II remains stationary.

In order to prevent the spring 5I from electing the pawl from the guideway 46 during an assembling operation, the guideway has, projecting from one of its side walls, a lug 48 located in a recess 50 in the pawl. The opposite ends of the recess 50 form abutments 49 sulciently spaced to permit the necessary reciprocal travel of the pawl.

It will be observed from the foregoing description taken in connection with the accompanying drawing that there is provided a very simple and eifective counter wheel unit which may be manufactured at a relatively low cost and thelparts of which may be quickly and readily assembled. The arrangement permits the driven member and numeral wheel to be formed of plastic. In assembling the parts, the reset pawl 45 and the spring 5I are positioned in the, guideway 46, and the pawls I2 and the springs 33 are positioned within the guideways or grooves 21 in the disk portion II" of the driven member. The

plate P is slid onto the hub I5 of the wheel and then the driven member is slid onto this hub. The plate P serves to retain the reset pawls and the ratchet pawls in their respective grooves, and acts as a bearing on which the lateral or opposed faces of the pawls may slide. The plate P also prevents the pawls from moving laterally from their respective guideways and thereby prevents each pawl from interfering with the reciprocal movement of the other.

As many changes could be made in the above construction and many apparently' widely different embodiments of this invention could be made without departing from the scope thereof, it is-intended -that .all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrativeand not in a limiting sense.

It is also to be understood that the language used in the following claims is intended to cover all of the generic and speciiic features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

I claim as my invention:

1. In a resettable counter' unit, an integral numeral wheel adapted to be rotatably mounted on a reset shaft and lhaving a web and a peripheral flange carried by the web and provided with an internal ratchet wheel; a reset pawl carried by said wheel and arranged to engage the reset shaft during a resetting operation, agear member having a central opening whereby said gear member may be journaied with respect to said numeral wheel, said gear member having any integral disk portion located within said peripheral flange and provided on its inner face with a groove disposed on a chord spaced from and located to one side of said opening, said groove leading from the periphery of said disk and having an abutting wall spaced from the open end thereof, a ratchet pawl mounted for reciprocation in said groove and having its outer end engageable with said ratchet wheel, and a compression spring between said abutting `wall and therear end of said ratchet pawl for urging lthe pawl into engagement with said ratchet wheel.

2.' In a resettable counter unit, a numeral wheel having a hub rotatably mounted on a resetshat, a web extending from the hub, and a pawl carried by said wheel and arranged to engage the reset shaft during a resetting opera-` tion, a gear member having a central opening for receiving said hub whereby the gear member may be journaled pn the hub, said gear member having an integral disk portion'within said peripheral flange and provided on its inner face with a pair of grooves chordally arranged to opposite sides of and substantially at like distances from the center of the disk and leading from the periphery of said disk portion at substantially diametrically opposite points, each of said grooves having an abutting wall, a ratchet pawl mounted for reciprocation in each of said grooves and having its outer end engageable with said ratchet wheel, and a compression spring between the rear end of each ratchet pawl and the abutting wall of the groove in which the pawl is located.

3. In a resettable counter unit, a numeral Wheel having a hub rotatably mounted on a reset shaft, av web extending from the hub, and a peripheral iiange carried by the web and provided with an internal ratchet wheel; a reset pawl carried by said wheel and arranged to engage the reset shaft during a resetting operation, a gear member journaled on said hub and having an integral disk portion located within said peripheral flange and provided on its inner face with a pair of grooves arranged on chords disposed to opposite sides of a diametrical line passing through the center of said 'gear member, each groove leading from the periphery of said disk portion and having an abutting wall spaced from its open end and a lug extending into the groove between said open end and abutting Wall, a ratchet pawl mounted for reciprocation in ea'ch groove and having an outer end engageable with said ratchet wheel, each ratchet pawl having a recess on its under side accommodating said lug and provided with an inner end wall adapted to engage said lug for limiting outward movement ofthe pawl, and a coiled spring located in each groove between said abutting wall and the rear end of the ratchet pawl.

4. In a resettable counter unit, a numeral Wheelhaving a hub adapted to be rotatably mounted on a reset shaft, a web extending from the hub, aud a peripheral flange carried by the web provided with an internal ratchet wheel; a reset pawl carried bysaid wheel and adapted to cooperate with the reset shaft during a resetting operation, a gear member having a central opening receiving said hub whereby the gear member may be journaled on the hub, said gear member having an integral disk portion located within said peripheral flange and provided on its inner face with a pair of grooves chordally arranged to opposite sides of and substantially at like distances from the center of said disk and leading from the periphery of said disk portion, a ratchet pawl mounted for reciprocation in each of said grooves and having its outer end engageable with said ratchet wheel, a compression spring in each groove behind the ratchet pawl therein for urging the pawl into engagement with said ratchet wheel, a plate about said hub and interposed between the opposing faces of said disk and web for preventing said ratchet pawls and springs from moving laterally out of said grooves. v

HARVEY N. BLISS.

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