US3728961A

US3728961A - Arrangement for electromagnetically setting drum series print wheels

Info

Publication number: US3728961A
Application number: US00160714A
Authority: US
Inventors: H Gross; S Gross
Original assignee: GROSS CASH REGISTERS Ltd
Current assignee: Chubb Cash Registers Ltd; GROSS CASH REGISTERS Ltd
Priority date: 1970-07-18
Filing date: 1971-07-08
Publication date: 1973-04-24
Anticipated expiration: 1990-04-24
Also published as: GB1313375A

Abstract

A printing device, e.g., for a calculator having a row of print wheels located in relative positions by a series of pawls which in turn are actuated by electromagnetic coils through stems which are shaped to such angles at their pawl engaging ends that the coils can occupy a wider space than the wheels and pawls.

Description

United States Patent [1 1 Gross et a].

[451 Apr. 24, 1973 ARRANGEMENT FOR ELECTROMAGNETICALL Y SETTING DRUM SERIES PRINT WHEELS Inventors: Henry Gross; Samuel Gross, both of London, England Gross Cash Registers Limited, London, England Filed: July 8, 1971 Appl. No.: 160,714

Assignee:

Foreign Application Priority Data July 18, 1970 Great Britain ..34,929/70 U.S. Cl. ..10l/99, 335/262, 335/267, 335/268 Int. Cl ..B41j 45/00, B4lj l/6O Field of Search ..lOl/93 C, 99, l 10, 101/96, 97, 98, 95; 197/]; 335/262, 263,

References Cited UNITED STATES PATENTS 4/1957 Shepard ..101/93 C 6/1965 Foley ct al. 101/399 X 8/1966 Peters 1 197/53 12/1966 Wasserman ...10 1/93 x 3/1967 Hickerson ..l97/ l 8 H1969 Bakardjiev et a1 ..l01/99 X 3 1970 Potter et al. ...101/93 c 6/1971 Guzak ...lOl/93 C 2/1971. DePuy et al. ..lO1/93C Primary Examiner-William B. Penn Attorney-Alexander & Dowell ABSTRACT A printing device, e.g., for a calculator having a row of print wheels located in relative positions by a series of pawls which in turn are actuated by electromagnetic coils through stems which are shaped to such angles at their pawl engaging ends that the coils can occupy a wider space than the wheels and pawls.

6 Claims, 2 Drawing Figures ARRANGEMENT FOR ELECTROMAGNETICALLY SETTING DRUM SERIES PRINT WHEELS This invention relates to printing devices for cash registers, computing weighing machines and other machines especially those in which the data is transmitted to the printing devices by electric pulses.

In order to arrange an adequate number of printing wheels in a comparatively small width, the wheels are made somewhat thin and not much more than is required by the size of the print type on the peripheral surface of the wheels. These may carry ratchet teeth in accordance with the invention described in our copending British Pat. application Ser. No. 34,928/70 filed coincidentally herewith or they may be connected with separate ratchet means of the same thickness. Pawls are required to engage the ratchet means to locate them in required positions and the pawls are operated by solenoids. However, solenoids of equally small size are expensive to make and require unduly large voltage and current.

According to the present invention we provide a printing device having a number of printing wheels side by side, pawls and ratchets associated with the printing wheels for stopping the wheels in required positions, electromagnetic devices including coils, for operating the pawls, said coils being of greater width than the printing wheels and arranged in at least two lines parallel to each other, each having a stem for transferring motion from the electromagnetic device to a pawl, the stems having their pawl engaging ends lying between two planes which are parallel to each other and close together, the pawl engaging ends of at least most of the stems being angled so that the pawl engaging tips of the stems are all spaced apart from each other along the double row and the double row is about the same length as that occupied by the pawls and ratchet means and printing wheels and less than that of the double row of coils.

The invention is illustrated by way of example in the accompanying diagrammatic drawing wherein:

FIG. 1 is a perspective view of a part of a device made in accordance with the invention; and

FIG. 2 is an end view thereof.

The printing device comprises a row of printing wheels (FIG. 2) having ratchet teeth 11 and printing characters 12. These wheels are mounted on a common spindle and each has a spring 13 to urge it in the anticlockwise direction of FIG. 2. A rod 15 extends through slots 16 in the wheels and can be moved to release the. wheels so that they rotate under the int fluence of the springs 13 until they are arrested by pawls 19 one of which is provided for each wheel. The pawls l9 and wheels thus extend in a row. The rod 15 is operated by pinion l4, toothed segment 17, and cam 18.

The pawls are two armed and are actuated to their printing wheel stopping positions by the action of solenoid coils 20. The solenoids are mounted in brackets 21 which are carried by a mounting plate 22 by bolts 23 which also carry a guide plate 24. The mounting plate is in turn mounted on a base plate 26 which forms part of a frame 27. The frame '27 carries a top guide plate 28.

The solenoids have movable armatures 30 connected by cross-strips or pins 31 to stems arranged in two rows, 32 33 parallel to each other and guided in slots in the

guide plates

24, 28. The pins 31 can move up through slots in the plate 24.

The solenoid coils 20 are in two rows parallel to each other and their axes are all parallel to each other. In this example each row consists of eight solenoids. Each solenoid may have a diameter of about half an inch so that the double row is about 4 inches long. They are required to operate the pawls which (and the wheels) are about 3 inches overall width or even less.

Above the guide plate 28 the upper ends of the

stems

32, 33 are shaped to converge to the required smaller length but with all the upper tips that contact the pawls spaced apart from each other lengthwise of the double row. The ends of the stems to the left of the central plane of the device are a mirror image of the ends to the right of the central plane. The upper ends of the two rows of stems lie between two closely spaced planes indicated by the arrows 36 and in fact the extreme tips may (as shown) be bent into line with each other, i.e., so as to lie between two very closely spaced planes Indicated by the arrOws 37.

The ends or tipS of the stems are together about the same length as the width occupied by the pawls with the ratchet teeth and the printing wheels and less than that of the double row of solenOid coils. The stems are between the double row of coils and extend above and below the coils.

The ends of the solenoid coils may be connected to a printed circuit (not shown) attached by a push-on connector to the output of a calculator circuit.

If desired the solenoids may be replaced by electromagnetic devices having armatures fixed in their coils and operating by magnetic attraction directly on the ends of the stems.

The device includes members 40 for pressing paper 41 against the row of printing characters. An inking ribbon (not shown) will also be provided.

What we claim is:

l. A printing device having a number of printing wheels side by side, said wheels having ratchet teeth thereon, pawls engageable with said ratchet teeth for stopping the wheels in required positions, said pawls having an axial overall dimension approximately the same as that of the printing wheels, electromagnetic devices including a set of coils and movable armatures for operating the pawls, said set of coils being of greater combined width than the combined width'of the printing wheels, said coils being arranged in at least two rows, the two rows lying in two planes which are parallel to each other, the coils all being parallel to each other, each electromagnetic device having associated therewith a stem arranged for transferring motion from the armature of the electromagnetic device to one of said pawls, each stem having a pawl engaging end, the stems lying in two rows located between the two rows of coils, the stems having their pawl engaging ends lying between two planes which are parallel to each other and close together, the stems acting on the pawls respectively to move the pawls into engagement with the ratchet teeth, the pawl engaging ends of at least most of the stems being angled in relation to the main parts of the stems in the direction to reduce the length of the row of tips of the pawl engaging ends to a length which is less than the width of the double row of the main parts of the stems and of the set of coils axially of the printing wheels and such that the pawl engaging tips of the stems are all spaced apart from each other along the double row of coils to engage the pawls and the double row length occupied by all the tips is about the same length and the width axially of the printing wheels occupied by the pawls and printing wheels.

2. A printing device as claimed in claim 1 wherein the stems project beyond the coils at both ends, the stems at one end being connected to the adjacent ends of the armatures of the electromagnetic devices and the other ends of the stems engaging the pawls.

3. A printing device as claimed in claim 2, having a plate to which are attached the ends of the coils near

Claims

1. A printing device having a number of printing wheels side by side, said wheels having ratchet teeth thereon, pawls engageable with said ratchet teeth for stopping the wheels in required positions, said pawls having an axial overall dimension approximately the same as that of the printing wheels, electromagnetic devices including a set of coils and movable armatures for operating the pawls, said set of coils being of greater combined width than the combined width of the printing wheels, said coils being arranged in at least two rows, the two rows lying in two planes which are parallel to each other, the coils all being parallel to each other, each electromagnetic device having associated therewith a stem arranged for transferring motion from the armature of the electromagnetic device to one of said pawls, each stem having a pawl engaging end, the stems lying in two rows located between the two rows of coils, the stems having their pawl engaging ends lying between two planes which are parallel to each other and close together, the stems acting on the pawls respectively to move the pawls into engagement with the ratchet teeth, the pawl engaging ends of at least most of the stems being angled in relation to the main parts of the stems in the direction to reduce the length of the row of tips of the pawl engaging ends to a length which is less than the width of the double row of the main parts of the stems and of the set of coils axially of the printing wheels and such that the pawl engaging tips of the stems are all spaced apart from each other along the double row of coils to engage the pawls and the double row length occupied by all the tips is about the same length and the width axially of the printing wheels occupied by the pawls and printing wheels.

3. A printing device as claimed in claim 2, having a plate to which are attached the ends of the coils near the pawls, and said plate is provided with openings through which the stems project so as to be guided thereby.

4. A printing device as claimed in claim 1, wherein the electromagnetic devices are solenoids having circular coils.

5. A printing device as claimed in claim 1, wherein the electromagnetic devices have fixed poles adapted to operate the stems by magnetic attraction.

6. A printing device as claimed in claim 1, wherein the pawl engaging tips of all the stems are in line with each other.