US2798671A - Stabilized counter - Google Patents

Description

y 1957 H. N. BLISS 2,798,671

STABILIZED COUNTER Filed Jan. 6, 1955 F/ G. E

Z J I 1 x INVENTOR HARVEY N Buss ATTORNEYS Unit llC

2,798,671 srnsnrznn counrnn Harvey N. Bliss, Windsor, Conn, assignor to "eeder- Root, Incorporated, Hartford, Conn, a corporation of Connecticut Application January 6, 1955, Serial No. 489,161

Ill Claims. (Cl. 235-92) The present invention relates to counters and more particularly to so-called magnetic counters which are operated by a solenoid utilizing a ratchet drive to the number wheels. More particularly, the invention relates to an improved locking arrangement for such counters which prevents advance of the count thereof due to jarring or vibration.

Electromagnetically operated counters having a ratchet driving connection between the driving solenoid and number wheels usually are susceptible to the registry of an erroneous count when severely jarred or when subjected to certain conditions of vibration. The reason for this is that in such counters the ratchet drive between the solenoid and number wheels may be actuated to advance the number wheels independently of actuation of the solenoid, particularly when the counter is severely jarred or subjected to vibration such that inertia or other forces displace the parts forming the ratchet drive in the direction of their normal driving movement. The possibility of obtaining an erroneous count in this way, either accidentally 'or fraudulently, is of course particularly ob jectionable, and sometimes prohibits the mounting of such counters on objects subject to severe vibration, such as heavy machines or the like.

One object of the present invention is to provide in electromagnetically operated counters of the character described a simplified and effective locking arrangement for positively preventing erroneous advance of the count thereof, even during severe jarring or vibration.

Another object is to provide in an electromagnetically operated counter having a ratchet drive to the number wheels a latch operated by the counter driving electromagnet and arranged to lock the counter during the intervals in which the driving electromagnet is not energized and to automatically unlock the counter to permit normal operation thereof when the driving electromagnet is energized.

Another object is to provide a locking arrangement of the character described which is readily adaptable for application in a variety of electromagnetic counters now on the market.

Another object is to provide in a counter of the character described a number wheel locking arrangement which occupies relatively little space which is simplified in structure and inexpensive to manufacture, and which operates automatically and without interfering in any way with normal counter operation.

Other objects will be in part obvious, and in part pointed out more in detail hereinafter.

The invention accordingly consists in the eatures of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set forth and the scope of the application of which will be indicated in the appended claims.

In the drawings:

Figure 1 is an elevation view, with a portion broken away, of a magnetic counter provided with a locking arrangement constructed in accordance with the present invention;

Figure 2 is a partial sectional view to an enlarged scale of the counter of Figure 1 taken on the line 22 thereof; and V Figure 3 is a perspective view of a portion of the structure shown in Figure 2.

Referring to the drawing, the invention is illustrated in connection with :a counter which includes a frame 2 journaling a horizontal shaft 4 on which are rotatably mounted a plurality of number wheels 6, 8 etc. of successively higher order, each inscribed on its periphery with successive numerals running from zero to 9. Suitable transfer gearing, including a transfer pinion 12 mounted on a transfer pinion shaft 14 parallel to shaft 4, connects each pair of adjacent number wheels. The transfer gearing serves in the usual manner to advance the number wheel of higher order at the completion of each counting cycle of the number wheel of lower order, while holding the number wheelof higher order stationary at all other times. In the top of the frame 2 is a viewing window 16 through which the count on the number wheels may be read. In the counter shown in the drawing, the shaft 4 is a rotatable reset shaft, and each number wheel is provided with a suitable internal reset pawl, not shown, which cooperates with the reset shaft in the usual manner to permit resetting of the number wheels to their zero position when the shaft is rotated in a clockwise direction as shown in Figure 2. To facilitate rotation of the shaft 4- during resetting, a knob 18 is mounted on theend of the shaft.

The electromagnetic drive for the counter includes a solenoid 20 having a vertically reciprocahle armature 22 which is connected by alink 24 to a pawl plate 26. The pawl plate is pivotally mounted on the transfer pinion shaft 14 and has an arcuate slot 28 which accommodates the shaft 4 and permits the plate to pivot relative thereto. An advance pawl 30 carried by the pawl plate 26 is biased by a spring 32 into engagement with a ratchet wheel 34. The ratchet wheel 34 has one tooth for each numeral on the number Wheel 6 of the lowest order and is directly connected to the number wheel 6 by pins 36. With this arrangement each time the solenoid 20 is: energized, the armature 22 is pulled downward, the pawl plate is pulled down by the link 24, and the advance pawl 30 advances the number wheel 6 one number. When the solenoid is de-energized, a spring 38 carried by shaft 14 returns the plate 26, link 24 and armature 22 to their uppermost position, in which position the free end of the pawl plate contacts and is stopped by the roof of the frame.

In accordance with the invention, the counter is provided with means for positively preventing any advance of the number wheels except when the solenoid is energized, such means thereby insuring that no advance of the number wheels can be caused by jarring or vibration of the counter, even to a severe degree. To this end the counter is provided with a latch in the form of a locking pawl 44 of magnetizable material mounted for pivotal movement on a shaft 46 disposed to one side of the solenoid armature 22, as viewed in Figure 2, and parallel to shaft 4. Cooperating with the latch is a latchable member connected to the number wheel 6 of lowest order and shown in the drawings as a disc-shaped latch wheel 40 mounted concentrically between the ratchet wheel 34 and number wheel 6. The periphery of the latch wheel 40 is formed with a plurality of evenly spaced, radially extending rectangular notches 42, one for each numeral on the number wheel. While the latch wheel is illustrated as separate and distinct from the ratchet wheel 34, it will be recognized that the two parts may be integral, and in fact the latch wheel 40 may perform a dual function and cooperate with both the locking pawl 44 and the advance pawl 30 as a portion of the ratchet drive, thereby eliminating altogether the necessity for a separate ratchet wheel 34.

The locking pawl 44 is formed with a flat shank portion 48 which traverses the field of the solenoid above the armature 22 and is slotted or cut away at 52 to provide a clearance space through which the link 24 extends. On one side of the slot the pawl 44 is formed with an upstanding finger 54 which is arranged to engage with the respective notches 42 in the latch wheel in each full figure position of the number wheel 6, and thereby positively lock the latch wheel 40 and number wheel 6 against rotation. The upper end face of the finger 54 is preferably beveled so as to seat squarely in the bottom of the latch wheel notch 42 with which it engages. The pawl 44 is counterbalanced by a thickened portion 50 on the opposite side of shaft 46 from shank 48, and is urged into engagement with a notch in the latch wheel 40 by a light spring 56 mounted on the shaft 46 and acting between the top of the solenoid and a horizontal finger 58 on the free end of the shank 48.

With this arrangement, it may be seen that when the solenoid is not energized, movement of the ratchet or number wheel is positively prevented by the engagement of the finger 54 with a notch 42 in the latch wheel 40. The balanced condition of the locking pawl renders it substantially immune to the effects of jarring or vibration, so that even though spring 56 is relatively weak, finger 54 will remain firmly seated in a notch 42 even under adverse conditions. Thus, even though the counter may be subjected to severe jarring or vibration such as might otherwise displace any of the parts of the driving connection between the solenoid and number wheel 6 sufficiently to rotate the ratchet 34 and advance number Wheel 6, the latching arrangement effectively prevents any such erroneous advance of the number wheel from taking place. Upon energizing of the solenoid 20, however, its magnetic attraction of the shank .48 overcomes the force of the lightspring56 and draws the pawl 44 downwardly simultaneously with the armature-22, thereby disengaging the finger 54 from the latch wheel 40 so as to permit normal rotation of the number wheel 6 by means of the advance pawl 30 and ratchet 34. The low inertia afforded by its counterbalanced condition and the lightness of spring 56 enable the pawl 44 to respond very quickly. The relative dimensions of finger 54 and notches 42 are such as to insure complete disengagement of the pawl 44 so that the number wheel 6 may advance freely and without interference of any kind when the solenoid is energized.

For the purpose of disengaging the locking-pawl 44 from the latch wheel 40 to permit free rotation of the ratchet wheel 34 and number wheel 6 during resetting of the counter herein illustrated, the locking pawl is also formed with an upstanding arm 6'!) having abeveled surface at its free end which engages the periphery of a cooperative disc-shaped reset cam 62 mounted on the shaft 4. The reset cam has a radius such that when the shaft 4 is rotated the cam displaces the end of the arm 60 and depresses the locking pawl 44 sufficiently to disengage the finger 54 from the latch wheel 46, thereby permitting the lowest order number wheel 6 to be rotated freely during the resetting operation. In counters of the nonresettable type, or in resettable counters wherein the lowest order number wheel may be advanced during resetting without moving the driving mechanism, an arrangement such as arm 60 and cam ,62 would of course not be required. A V

A radialdepr ession 64 in the reset cam registers with the end of the arm 60 when the reset shaft 4 is rotated to the fully reset position of the number wheels, and thereby permits spring 56 to raise the locking pawl 44 enough to reengage the-finger54 with a notch 42 in the latch wheel 40. Withthis arrangement, however, failure to rotate shaft 4 completey during resetting or inadvertent reverse rotation of shaft 4 from its fully reset position would cam arm 60 out of depression 64 and depress the locking pawl 44 out of engagement with the latch wheel 40. To prevent this occurrence, a pawl 66 is pivotally mounted on the frame and engages with a notch in a boss 68 on the shaft so as to prevent reverse rotation of the shaft from its fully reset position.

Summarizing the operation of the counter, when the solenoid is energized to register a count, downward movement of the armature 22 pulls both the link 24 and the locking pawl 44 down with it, the finger 54 thereby being disengaged from the latch wheel so as to free the latch wheel 40 and number wheel 6 for rotation as the pawl plate 26 is pulled down and the advance pawl 30 turns the ratchet wheel 34. When the solenoid is deenergized, however, the spring 56 returns the locking pawl to its uppermost position and re-engages the finger 54 in the next notch 42 in the latch wheel, thereby securely locking the lowest order number wheel 6 against rotation so that erroneous advance of the counter is impossible. The counterbalanced condition of the locking pawl renders it substantially immune to displacement by jarring or vibration, enabling spring 56 to'be very light and thereby providing maximum sensitivity to solenoid operation while insuring that the counter will remain securely locked even though subjected to severe jarring or vibration or the like. 'To permit free rotation of number wheel 6 during resetting, upon rotation of shaft 4 the reset cam 62 depesses the lockingpawl 44 and disengages the finger 54 from the latch Wheel, and upon rotation of the number wheels to their reset position, the arm 60 again registers with and enters the depression 64 in the reset cam, allowing the finger 54 to re-engag'e the latch Wheel and again lock the counter;

. 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 drawings shall be interpreted as illustrative and 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 specific 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:

1. An electromagnetically operated counter comprising a frame, a number wheel rotatably mounted in the frame, a solenoid having a movable armature, a ratchet drive between the armature and the number wheel, a latchable member connected to said number wheel for rotation therewith, and a spring biased latch normally preventing rotation of the latchable member when the solenoid is deenergized and operated by the solenoid to enable rotation of the latchable member when the solenoid is energized.

2. An electromagnetically operated counter comprising a frame, a number wheel rotatably mounted in the frame, a solenoid having a movable armature, a ratchet drive between the armature and the number wheel, a latchable member connected to said number wheel for rotation therewith, and a latch normally engaged with said latchable member to prevent rotation thereof and operable in response to energizing of said solenoid to release said latchable member.

3. An electromagnetically operated counter comprising a frame, a number wheel rotatably mounted in the frame, a solenoid having a movable armature, a ratchet drive between the armature and the number wheel, a latchable member connected to said number wheel for rotation therewith, a latch engageable with the latchable memher to prevent rotation thereof, said latch having a magable member when the solenoid is energized, and a spring for biasing the latch into engagement with the latchable member when the solenoid is not energized.

4. An electromagnetically operated counter comprising a frame, a number wheel rotatably mounted in the frame, a solenoid having a movable armature, a ratchet drive between the armature and the number wheel, a notched wheel connected to said number wheel for rotation therewith, a latch pivotable between a position in engagement with said notched wheel and a position disengaged therefrom, said latch having a pivot axis at its center of balance and having a magnetic portion disposed in the field of said solenoid and movable thereby to disengage the latch from the notched wheel when the solenoid is energized, and a spring for biasing the latch into engagement with the notched wheel when the solenoid is not energized.

5. An electromagnetically operated counter comprising a frame, a shaft journaled in the frame, a plurality of rotatable number wheels mounted on the shaft, a solenoid having a movable armature, a ratchet drive between the armature and one of the number wheels, at disc-shaped latch wheel secured to said one number wheel for rotation therewith and having a plurality of peripheral notches corresponding in number to the numerals on said one number wheel, a pawl of magnetic material engageable with said notches in each of the full figure positions of said one number wheel to prevent rotation thereof, said pawl having a portion extending through the field of said solenoid and movable by energization of the solenoid to disengage the pawl from the latch wheel, and a spring for biasing said pawl into engagement with the latch wheel when the solenoid is not energized.

6. An electromagnetically operated counter comprising a frame, a shaft journaled in the frame, a plurality of rotatable number wheels mounted on the shaft, a solenoid having a movable armature, a ratchet drive between the armature and one of the number wheels, a disc-shaped latch wheel secured to said one number wheel for rotation therewith and having a plurality of peripheral notches corresponding in number to the numerals on said one number wheel, a pivotable pawl of magnetic material having a pivot axis at its center of balance, said pawl having a portion engageable with said notches in each of the full figure positions of said one number wheel to prevent rotation thereof, said pawl having a second portion extending through the field of said solenoid and movable by energization of the solenoid to pivot the pawl out of engagement with the latch wheel, and a spring for biasing said pawl into engagement with the latch wheel when the solenoid is not energized.

7. A counter as defined in claim 6 wherein said shaft is a rotatable reset shaft, and a cam rotatable with said shaft is arranged to disengage said latch from said latch wheel responsive to rotation of said shaft during a resetting operation.

8. A counter as defined in claim 7 wherein said frame carries means engageable with said shaft for preventing reverse rotation of said shaft from its fully reset position.

9. An electromagnetically operated counter having a frame, a rotatable reset shaft journaled in the frame, a plurality of rotatable number wheels mounted on the reset shaft, means for rotating the reset shaft to reset the number wheels, a solenoid having a reciprocable armature, a ratchet wheel connected to the number wheel of lowest order and a pawl for rotating said ratchet wheel drivingly connected to said armature, a disc-shaped latch wheel secured to said number wheel of lowest order for rotation therewith and having a plurality of peripheral notches corresponding in number to the numerals on said one number wheel, a holding pawl of magnetic material engageable with a notch in said latch wheel in each of the full figure positions of said number wheel of lowest order to prevent rotation thereof, said holding pawl having a portion extending through the field of said solenoid and movable by energization of the solenoid to disengage the holding pawl from the latch wheel, a cam on the reset shaft for disengaging said holding pawl from said latch wheel when the reset shaft is rotated in one direction to reset the number wheels, and means on the frame engageable with the reset shaft in the fully reset position thereof for preventing rotation thereof in a direction opposite to said one direction.

10. In -an electromagnetically operated counter, a frame, a number wheel rotatably mounted in the frame, a solenoid, driving means for advancing the number wheel in one direction when the solenoid is energized comprising a ratchet wheel secured to the number wheel, a ratchet pawl for actuating the ratchet wheel, and a first armature associated with the solenoid connected to the ratchet pawl, and a second armature associated with the solenoid hav ing means normally blocking operation of the driving means and movable to non-blocking position when the solenoid is energized.

References Cited in the file of this patent UNITED STATES PATENTS 2,514,788 Nelson July 11, 1950 2,522,734 Wood Sept. 19, 1950 2,636,680 Summers Apr. 28, 1953 2,673,685 Hoffman Mar. 30, 1954

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