US3601725A

US3601725A - Stepping switch

Info

Publication number: US3601725A
Application number: US845469A
Authority: US
Inventors: Fritz Hartmann
Original assignee: Fritz Hartmann
Current assignee: FRITZ HARTMANN GERATEBAU & Co A OF GERMANY GmbH LP
Priority date: 1968-07-30
Filing date: 1969-07-28
Publication date: 1971-08-24
Anticipated expiration: 1988-08-24
Also published as: CH490628A; DE1775334B2; DE1775334A1; ES370055A1; GB1220764A; FR2014785A1

Abstract

A stepping switch comprising a driving part including a magnet, an armature and a lever supported at one end and having oppositely disposed claws at its free end that is movable transversely of a driven part that presents pins, which are engaged by wedged flanks of said claws which have smooth sliding surfaces that snugly engage the smooth sliding surfaces of the pins to advance the driven part while the wear on the sliding surfaces is so negligible as to permit the use of plastic components.

Description

United States Patent Inventor Fritz Hartmann 852 lm Henschlaze, Erlangen-Sieglitzhof, Germany Appl. No. 845,469 Filed July 28, 1969 Patented Aug. 24, 1971 Priority July 30, 1968 Germany P 17 75 334.3

STEPPING SWITCH 9 Claims, 3 Drawing Figs.

US. Cl 335/140, 200/156, 74/128, 74/575 Int. Cl "01h 51/08 Field of Search 74/575-578; ZOO/61.69, 156; 335/123, 140, 225,

[ References Cited UNITED STATES PATENTS 652,151 6/1900 Tirrill 335/140 3,373,622 3/1968 Stautmeister 74/577 X I FOREIGN PATENTS 1,303,756 10/1962 France 74/128 654,832 5/1961 Italy 335/123 Primary Examiner-G. Harris Attorney-Robert H. Jacob ABSTRACT: A stepping switch comprising a driving part including a magnet, an armature and a lever supported at one end and having oppositely disposed claws at its free end that is movable transversely of a driven part that presents pins, which are engaged by wedged flanks of said claws which have smooth sliding surfaces that snugly engage the smooth sliding surfaces of the pins to advance the driven part while the wear on the sliding surfaces is so negligible as to permit the use of plastic components.

STEPPINC swncu BACKGROUND or THE INVENTION The presentinvention relates to stepping switches orstepbystep switch systems. Switches ofthis type are used for many purposes such as storage of measurement andpro'duction data with interrogation, controls and preselection in tool machines, seat ticket booking on railways, automatic game devices, printers for interrogation of counter readings, statistical. quality :control devices. The stepping switch in accordance with the invention is of the type where the driven part is provided with SUMMARY OF THE INVENTION In accordance with the invention the driving part has a pair of transport claws or teeth grooved to define wedges that face one another, the wedge flanks of which'alternately engage the transmitting pins of the driven part from one side and then from the other and thus drive that part in the direction of advancement. A substantial load reduction on the cooperating components can be obtained in that the transmitting pins of the driven part and the wedge-shaped flanks of the driving part have arched surfaces that are in snug or flush engagement with one another. Most suitable for this purpose are four cornered transmitting pins which have convexly or concavely arched lateral surfaces. They may be of generally rhomboidal cross section.

The stepping switch in accordance with the invention differs advantageously from known stepping switches where the driving part which has one or more driving pins cooperates with rings having zigzag-shaped sliding surfaces disposed in a groove or rib.

BRIEF DESCRIPTION OF THE DRAWINGS Hereinafter an embodiment of the invention is described, where the driven part is a transporting wheel the advancing movement of which is circular, as illustrated in the drawings in DESCRIPTION OF THE INVENTION The driven element or part comprises, for example, disk la in the form of a dial wheel or a disk forming the rotor of a number collector and a ring of transporting pins lb associated therewith. The driving part includes a driving member or lever 20, which at its end carries two

transport claws

2b and 2b defining grooves presenting wedged flanks which face each other. The one claw 2b which is more remote from the axis of the wheel la has two grooves, the other claw 2b which is closer to the axis of the wheel has only one groove which is displaced with respect to the grooves of claw 2b by half their spacing in the direction of transport. The direction of transport is indicated by the arrow 10. The mutual distance of the

transport claws

2b and 2b in the direction of rocking of the lever that pendulates about radially relative to the transport wheel la is only slightly smaller than the diameter of the transporting pins lb measured in that direction. These pins have a substantially rhomboidal cross section and arched side surfaces which snugly engage the wedged flanks 2c and 2d of the claws or teeth of the driving part and slide on them during transporting movements. Thus, as distinguished from known stepping switches no sharp edges of one part slide on the sliding surface of the other part. Therefore the surface pressure is small during the transfer of the advancing force, so that the cooperating parts are not subject to any essential w'ear. Consequently they may be made of plastic or another material that would not normally be used for stepping switches of this type.

- In order toensure the flush orsnug engagement of the cooperating components at their sliding'surfaces during the entire advancing movement these parts are profiled in accordance with curves which result from therockingmovement of the driving part and the advancing movement of the driven part.

The advancing force here always engages the transporting pin lb arranged generally in a circle at the same distance from the axis 9 of the driven part 111, so that the moment of rotation remains practically unchanged during the advancing movement and is also not influenced by finishing tolerances or shrinking of the material of parts thatare subject to stress and surface wear. I g

The'transporting claws-2b and 2b are disposed at a small distance opposite from one another. Consequently, the moved mass of the driving part is small. Its oscillating or rocking distance is likewise small, so that only small quantities of energy are lost between the cooperating parts.

In the embodiment illustrated the lever 20 is an angular lever with arms of unequal length pivotally supported by a stud 8. A spring 3 tends to swing it in clockwise direction. It is driven by an electromagnet having an exciter coil 4 on which one leg of an elongated U-shaped core 5 is seated. The armature 7 is loosely held at its upper end as shown in FIG. 1, by a strap 6 mounted on the upperleg of the magnet, so that it can tilt or rock about this end. Its lower end is disposed in a recess or cup 2e in the-short arm of the lever 2a If the amiature is pulled up it rocks the lever counterclockwise while tensioning ,the spring 3, thereby engaging the upper claw 2b with a pin 1b of the transporting wheel.

The axis 9'of the driven part 1a and the pivot point 8 of the lever 2a are inthe region of the opposite ends of the driving magnet so that a greater length of the lever arm is obtained.

The lever end carrying the

transport claws

2b, 2b therefore makes an almost straight line rocking movement of small length, as already mentioned.

A further embodiment is illustrated in FIG. 3 where the transport claw or tooth.3b is provided at the end of lever 3a with slightly concave working surfaces 30, 3d drawn apart as compared with the embodiment of FIG. 1. The displacement of the transport claws 3c and 3d corresponds to one half step. As the stepping switch is actuated successive transport rollers lb and lb" are alternately seized by one side and then the other of the transport claws 3c 3d.

With the stepping switch described the transport wheel la effects its advancing movement in two half steps. If the coil 4 of magnet 5 receives a current impulse, the lever arm carrying the transport claws is swung away from the axis 9 of the wheel 10, while the sliding surface 2c of the upper claw 2b engages the upper flank of the transporting pin lb which is disposed opposite from it and advances it by one half step counterclockwise as the cooperating surfaces of the claw and of the pin slide on one another. When the current impulse ceases the armature withdraws from the magnet core 5. The lever 2a thus released is pulled back to its position of rest by the spring 3. The lower left flank of the pin 1b is engaged by the surface 2d of the claw 2b and the pin is moved asecond half step while the cooperating surfaces snugly slide on one another. These operations are repeated with each current impulse as soon as the magnet core is excited or desensitized.

The switch is illustrated at an enlarged scale. In practice it Y can be produced essentiallysmaller with dimensions of a few centimeters, in which connection the transport wheel la with the pins lb on the one hand and the lever 2a with

transport claws

2b, 2b on the other hand may each be made as a unit, preferably of plastic material or light metal by injection molding.

A further advantage of the stepping switch in accordance with the invention is that it can be operated without a tension spring on the driven part. It permits high operating speeds and actuates the driven part practically without play and rebounding, so that any support of the switching operation by spring means acting on that part is unnecessary.

Having now described the invention with reference to the embodiments illustrated, what I claim as my invention is set forth in the appended claims.

1. Stepping switch having a driving part comprising a magnet, an armature and a driving member disposed in operative relationship to said armature and a rotatable driven element for operative engagement by said driving member, said driven element presenting a plurality of transporting pins arranged generally in a circle and said driving member having a pair of transport claws disposed along opposite edges with grooves presenting wedged flanks and being movable transversely relative to said driven element and said pins, said claws being spaced apart by a distance slightly larger than the diameter of said pins and opposite said claws being displaced with respect to one another by a distance corresponding substantially to one-half groove space, said wedged flanks alternately engaging a transporting pin of said driven element from one side and then from the other to move said element in advancing direction in response to said transverse movement of said driving member.

2. Stepping switch in accordance with claim 1 where said transporting pins and said wedged flanks present arched slidmovement.

3. Stepping switch in accordance with claim 2, where said.

transporting pins have four corners and present convexly arched surfaces on two adjacent sides and concavely arched surfaces on two opposite adjacent sides.

4. Stepping switch in accordance with claim 3, where said transporting pins are of substantially rhomboidal cross section.

5. Stepping switch in accordance with claim 2, where one said transport claw presents two wedge-shaped grooves and the other one groove displaced relative thereto in the direction of advancing movement.

6. Stepping switch in accordance with claim 5, where one said transport claw is displaced with respect to one said other claw by an angle corresponding to one half step.

7. Stepping switch in accordance with claim 5, where said sliding surfaces of the flanks of said claws and of said pins are profiled in accordance with curves evolved from the rocking movement of the driving member and the advancing movement of the driven element.

8. Stepping switch in accordance with claim 1, where said magnetis-elongated and where said driven element is in the form of a pinwheel having its axis at one end of said magnet and said driving member is a lever having a pivot at the op- UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 5 r Dated August Invent0r(s) Fritz Hartmann It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

The correct address of the Inventor is:

Signed and sealed this l th day of January I972.

(SEAL) Attest:

EDWARD M. FL ETC HEM, J i3. Attesting Officer ROBERT GOTTSCHALK RM PO-105O (10-69) USCOMM-DC 60376-1 69 U 5 GOVERNMENT HUNTING OFFICE '96? fi jbfi-ijd Acting Commissioner of Patents

Claims

2. Stepping switch in accordance with claim 1 where said transporting pins and said wedged flanks present arched sliding surfaces which engage one another snugly for sliding movement.

3. Stepping switch in accordance with claim 2, where said transporting pins have four corners and present convexly arched surfaces on two adjacent sides and concavely arched surfaces on two opposite adjacent sides.

8. Stepping switch in accordance with claim 1, where said magnet is elongated and where said driven element is in the form of a pinwheel having its axis at one end of said magnet and said driving member is a lever having a pivot at the opposite end of said magnet.

9. Stepping switch in accordance with claim 8, where at least one of said cooperating said driving member and said driven element is made of plastic material.