US3064891A - Stepping switch mechanism - Google Patents

Stepping switch mechanism Download PDF

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Publication number
US3064891A
US3064891A US772505A US77250558A US3064891A US 3064891 A US3064891 A US 3064891A US 772505 A US772505 A US 772505A US 77250558 A US77250558 A US 77250558A US 3064891 A US3064891 A US 3064891A
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pawl
drum
stepping
dial
driving
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US772505A
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Frank G Nicolaus
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LION Manufacturing CORP
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LION Manufacturing CORP
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    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06MCOUNTING MECHANISMS; COUNTING OF OBJECTS NOT OTHERWISE PROVIDED FOR
    • G06M1/00Design features of general application
    • G06M1/14Design features of general application for transferring a condition from one stage to a higher stage
    • G06M1/18Design features of general application for transferring a condition from one stage to a higher stage requiring external operation, e.g. by electromagnetic force
    • G06M1/183Design features of general application for transferring a condition from one stage to a higher stage requiring external operation, e.g. by electromagnetic force with drums
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06MCOUNTING MECHANISMS; COUNTING OF OBJECTS NOT OTHERWISE PROVIDED FOR
    • G06M1/00Design features of general application
    • G06M1/08Design features of general application for actuating the drive
    • G06M1/10Design features of general application for actuating the drive by electric or magnetic means
    • G06M1/102Design features of general application for actuating the drive by electric or magnetic means by magnetic or electromagnetic means
    • G06M1/104Design features of general application for actuating the drive by electric or magnetic means by magnetic or electromagnetic means electromagnets, clicks
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T74/00Machine element or mechanism
    • Y10T74/15Intermittent grip type mechanical movement
    • Y10T74/1526Oscillation or reciprocation to intermittent unidirectional motion
    • Y10T74/1529Slide actuator
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T74/00Machine element or mechanism
    • Y10T74/21Elements
    • Y10T74/2133Pawls and ratchets
    • Y10T74/2141Sliding pawls

Definitions

  • Another feature resides in utilizing said pawl for the dual functions of stepping the drum and indexing or stopping it at an exactly registered position during each operating cycle of the pawl.
  • Additional features relate to the provision of a mounting means for a plurality of the stepping units so contrived that each unit is removably positionable in an exact position relative to its own display window before which the indicia on said drums will be positioned in exact registry owing to the exact stopping action of the indexing pawl means Still further features relate to the construction and operation of the combination stepping and indexing pawl means with respect to special guiding and bearing means therefor formed as a part of a chassis or base plate, together with a novel means for coupling the pawl to its solenoid plunger.
  • FIG. 1 is a front elevation of a triplet-mounted score indicating assembly
  • FIG. 2 is a horizontal section along lines 22 of FIG 1 with parts seen in plan view;
  • FIG. 3 is a (right) side elevation of the step-switch and dial assembly
  • FIG. 4 is an elevational detail of one of the printedcircuit panels
  • FIG. 5 is a vertical elevation looking inwardly on the ratchet and dial mechanism of one of the stepping units
  • FIG. 5-A is a magnified fragmentary detail of the indexing action
  • FIG. 6 is a transverse vertical section taken along lines 66 of FIG. 3 detailing the indexing teeth and pawl means .on one dial unit;
  • FIG. 7 is an operating detail based on FIG. 3;
  • FIG. 8 is another operating detail showing certain functional positions of only the ratchet pawl means
  • FIG. 9 is a top plan detail of the novel driving and indexing pawl
  • FIG. 10 is a perspective of the novel driving and indexing pawl
  • FIG. 11 is a fragmentary, exploded perspective detail of the means for coupling the solenoid plunger to the pawl.
  • FIG. 1 The embodiment of the invention depicted in FIG. 1 comprises three digital-countingstep-switch and dial units A, B, and C, carried on a novel mounting bracket 28' having an upset front wall 21 provided with three sightopenings 21A, 21B, 21C, each corresponding to one of the units A, B, or C disposed therebehind.
  • the mounting bracket as in FIG. 2, has a bottom shelf 3,064,891 Patented Nov. 20, 1962 22 (FIG. 2) on which each of the plurality of units A, B, and C is independently and removably seated and secured.
  • a simple means is provided for seating and securing each of the units A, B, and C on the shelf plate 22, and consists, as seen first in FIG. 2, of the provision at the rearward edge of said plate, of an open-ended marginal slot 24 extending inwardly of the plate in alignment with an upset and slotted lug 25 located close to the opposite boundary (i.e. the down-turned attaching flange 23) of the shelf plate.
  • V i V i
  • each of the individual step switch and indicator units A, B, and C is provided with a chassis plate or base in the form of a one-piece stamping consisting of a main upset along its bottom margin (FIGS. 2 and 3) a bottom or foot flange 31 and al-ong its side margin a back wall or flange 32.
  • Means for locating and removably securing the chassis plates on the mounting bracket includes, as in FIG. 3, the provision on the foot or bottom flange 31, of a stud-like member such as the screw 31X fitting in the shelf slot 24, and spaced therefrom a slot 31Z interfitting with the shelf lug 25, and the latter, with screw 31X, provides a slip-on mounting means making it easy and quick to remove individual stepper units.
  • a further aspect of the locating means includes the provision of a spacer lug 33 (FIGS. 2, 3, and 7) formed as a forward projection from each main chassis plate 30, and of a size to abut the inside face of the vertical mounting bracket plate 21 to locate each stepper unit exactly at the same distance from the corresponding Window 21A, 21B, 210.
  • This locating means greatly expedites the installation of individual units in manufacture and in servicing
  • the step-switch and indicating dial mechanism includes a spindle 39 (see also FIG. 2) suitably staked into the vertical chassis plate 30, and upon which is rotatably received a hub assembly, such as shown in FIG.
  • the hub structure is preferably made from a synthetic moldable material of the class of nylon or the like.
  • a small, light-Weight plastic number dial or drum 50 having digital indicia about its outside periphery, as for example the numerals 0 to 9,
  • the ratchet gear as seen in FIG. 8, is provided with ten teeth 43 each corresponding to one of said numerals on the drum, and the ratchet is stepped by means of the plate portion 30 having" install and peculiarly shaped pawl depicted in FIGS. 8, 9, and 10, the same being a one-piece molded member, preferably formed of nylon.
  • the pawl 60 is a somewhat elongated member having a decided laterally offset bight 61 formed in its mid-region.
  • a special index tooth 64 is provided on the inside of the bight near the righthand or trailing end of the pawl, the purpose of which will appear more fully hereafter.
  • a stepping tooth 66 At the left-hand end of the pawl is an integral, pendant spring-attaching lug 65, and just above it, a stepping tooth 66, while nearer the bight is an integral, upstanding guide finger 67.
  • the right-hand end of the pawl is rounded and pierced, as at 68, for coupling by novel means with a driving member such as the plunger 74 of an electromagnet 70 mounted by means of a screw strap 71 on the rearward flange 32 of the chassis plate (FIG. 7).
  • a driving member such as the plunger 74 of an electromagnet 70 mounted by means of a screw strap 71 on the rearward flange 32 of the chassis plate (FIG. 7).
  • the coupling means between the pawl and driving plunger is illustrated in FIG. 11 and consists in the provision of a longitudinal slot 75 in solenoid plunger 74 and a transverse pin hole 76 to receive a pin 77 which will traverse the pawl hole 68 when the appertaining end of the pawl is inserted in said slot 75.
  • a wide annular seating groove 78 Formed circumferentially about the plunger 74 at the pin hole 76 is a wide annular seating groove 78 of a size to receive a thin plastic collar 79 split as at 79X and adapted to fit easily into said groove after the retaining pin 77 has been inserted.
  • the aforesaid coupling arrangement has the advantage of great simplicity and efficiency in assembly and in operation, it being especially important that the collar 79 serves the purpose of removably securing the pin 77 and acting as a bearing for the free end of the plunger, and at the same time, owing to the split 79X, permitting free lateral or rocking motion of the attached end of the pawl, by reason of which the driver end of the pawl is considered to be provided with a floating type of bearing.
  • FIG. 8 illustrates the normal, spring-urged position of the pawl, in which condition it will be observed that the pawl tooth 66 is fully flush against the engaged ratchet tooth 41A.
  • the driving stroke of this pawl is effected by spring 80 further tensioned by energization of solenoid 70 carried on an outboard bracket 71 (along with switch 100) on chassis flange 32. This driving action is illustrated in FIG. 7.
  • the pawl 60 is freely but accurately guided by stationary guiding formations which are integral parts of the chassis stamping, of which there are two below, and one above, the pawl, as depicted in FIGS. 7 and 8.
  • the upper stationary guide means is in the form of a wide lug 83 having a long slot 84 (FIG. 2) in which the upper end portion of the pawl guide finger 67 works easily.
  • Beneath the pawl is another offset chassis guide lug 85 substantially identical to lug 83, and guidedly receiving the pendant spring finger 65 of the pawl, and in FIG. 8 it will be noticed that the bottom of the pawl rides on the lug 85 in the normal position and at the terminal part of the driving stroke, whereas, according to FIG. 7, during part of the retractive stroke, the pawl is free rock upwardly so that driving tooth 66 can slip behind the next successive ratchet tooth 4113, as in FIG. 7.
  • the pawl In the retractive stroke, as last described above, the pawl is cocked upwardly to engage the succeeding tooth 41B by biasing action and location of the spring 8% owing to the fact, apparent in FIGS. 3 and 5, that the spring anchoring lug 81 is located somewhat above the level of its attachment to the depending spring finger 65 on the pawl, by reason of which the outer free end regions of the pawl tend to be lifted and are lifted as the pawl passes'from the last driven tooth to the next higher one.
  • the pawl tends to ride on lug 86 in all movements and to float guidedly in relation to the slotted portions of the other two lugs 83, 85; and to rest at certain times upon the outer, lower lug 85.
  • a pawl formed of an effective and light bearing material such as nylon, and lugs 83, 85, and 86 arranged as described and Serving both in constraining and supporting capacities, permits the pawl to move very easily and freely, yet with decided accuracy.
  • a further feature of great importance relates tothe indexing or stopping of the ratchet-driven mechanism at exactly the same position on each stroke.
  • poor and sporadic registry is a source of great trouble both in switching and indicating'operations, and much of the expense associated with the manufacture of more accurate stoppers is concerned with the problem of achieving consistently accurate steps at the highest speeds obtainable for the type of construction specified.
  • the present disclosures achieve commercially significant results in registry by providing axially-projecting stop or indexing teeth 58X (FIG. 6) on one axial margin of the number drum 50, each tooth corresponding to one dial numeral and therefore one stopping position.
  • the drum 50 is preferably formed of molded plastic aifording the greatest strength with least weight, and the drum is of a diameter and length (axially) and is so ournalled on spindle 39 that its circumferential web fits into the offset bight portion 61 of the driving pawl, as illustrated in FIGS. 3, 5, and 6, particularly.
  • each tooth 50X is cut flat and parallel to the center line CL (FIG. 5) and is not cut on a true radius through the center of the drum.
  • CL center line
  • the full area of this leading edge of the tooth falls fiat on the flat surface of pawl tooth 63 (FIG. 5A) instead of on a relatively sharper (and more variable and wearable) knife-edge, such as will occur where the tooth face is very narrow and formed on a radius.
  • FIG. 8 there is seen a pair of metal switch pawls 92, 93 mounted on a common pivot 94 suitably staked into the chassis plate and respectively urged by the two arms 95, 96 of a common spring 97, on said pin and seen in dotted lines in FIG. 7.
  • the nose of pawl 92. rides on the cam, and this pawl has a tail lever 92A disposed to project and alternately engage the blades of switch 160 and actuate the same in accordance with whether the pawl is riding the lobe 90 or dropped into the dwell 91.
  • the companion pawl 93 is situated to have its nose ride the teeth of the ratchet Wheel and this pawl serves the purpose of holding the ratchet, cam, and drum against displacement While the driving pawl and indexing means is in action.
  • the novel stepping unit is shown in FIG. 3 approximately to the actual scale of one of its commercial embodiments, together with a mounting bracket and positioning means capable of seating three such units for counting and indicating in one-digit steps from zero to 999.
  • Consistent performance of the described mechanism has been sustained for long periods at a rate of steps per second without error either as to positioning of the number dial or stepping on a proper switch contact, and while certain substantial economies in cost of manufacture actually have resulted from the special construction of the stepping pawl means and the drum-indexing feature, the best reliable speed of which a comparably constructed and costed stepping unit of the best prior construction is capable is about eight steps per second over a period of time of shorter trouble-free duration, there being a tendency of the prior devices when pushed to higher speeds to break down and make indexing and switching errors.
  • the new stepping mechanism has been found capable of a speed much higher than 25 steps per second under preferred conditions, and at either rating the performance is considered an innovation, which is ascribable mainly to the light-weight construction and free-moving stepping and indexing operation of the drum by the novel pawl means.
  • the compact character of the unit is achieved in part by the rapid and accurate operation of the stepping mechanism which makes it possible to employ smaller parts made of lightweight materials, together with the fact that the ratchet gears, pawls, and switch wiper are all located substantially within the hollow of the drum, the driving solenoid is located outside of the hollow of the drum with its plunger moving along a line approximately parallel to a radius of the drum axis and in confrontation to the cylindrical face of the drum.
  • peripheral margins being provided with stop teeth along said margin travelling in a path concentricaily of the rotative axis of the gear and driven dial member
  • each stepping operation of the pawl also includes a stopping operation by engagement of said part thereof with one of said stop teeth along the dial margin to arrest the driven dial member at a predetermined position in each stepping advance thereof.
  • said driven rotatable dial member is a cylindrical drum and has a hollow portion subjoining its rotative axis, and said ratchet gear and a substantial portion of said pawl are dis.- posed in substantial part in said hollow portion, and said pawl has an offset portion jogging around said peripheral margin of the drum to the exterior thereof for driving connection with said electromechanical means.
  • Mechanism according to claim 2 further characteriZed in that said electromechanical means includes a solenoid located exteriorly of the drum with a reciprocable plunger moving along a line opposite the cylindrical face of the drum.
  • Mechanism according to claim 1 further characterized by the provision of a chassis structure including a base plate and means for journalling said ratchet gear and dial member thereon, together with upset portions on said base plate for confining, guiding, and supporting, at least in part, said pawl in a path of reciprocation in operative relation to the racthet gear and dial member.
  • a ratchet gear having connected thereto a hollow drum rotatable coaxially thereof with the gear disposed in the hollow thereof; a driving pawl and means mounting the same for reciprocatory motion in unidirectional driving relation with said ratchet gear, electromechanical means including a solenoid having a plunger reciprocable to drive said pawl unidirectionally by action along the line of reciprocation of the pawl but outside of the drum, said pawl having one end portion disposed in said drum hollow for driving engagement with the ratchet gear, and an opposite end portion projecting outside of the drum hollow past an axial end of the drum and radially beyond the peripheral face thereof for connection with said solenoid plunger, and means rockably, drivingly interconnecting said pawl end and plunger.
  • a ratchet gear and dial drum turned thereby; a reciprocable pawl means driving said ratchet gear and having a laterally offset loop extending around an axial edge of the drum; index stop teeth on said drum edge located to engage a stop formation subjacent to saidloop in a predetermined normal position of rest of the pawl; said pawl and drum being constructed and relatively positioned such that, when both the drum and pawl are in motion concurrently, clearance is provided between said index teeth and stop formation, but one said index teeth always strike said stop formation as the pawl and drum come to rest at the end of each drum-stepping operation of the pawl, whereby the drum is accurately stopped by the same instrumentality employed to drive it.
  • a rotatable stepping ratchet gear In a step-up ratchet mechanism, a rotatable stepping ratchet gear, a hollow drum rotated coaxially with said gear, and stepping means including a stepping solenoid located outside said drum and having a plunger reciprocable in a direction toward the drum and transversely of its rotational axis, and a stepping pawl connected at one end outside the drum to said plunger and having an opposite end region turned around an edge of the drum with a stepping tooth located interiorly of the drum for driving coaction with said ratchet gear along an axis aligned with the axis of reciprocation of said plunger.
  • a base plate having a foot portion on which the plate can rest in upright position; stepping mechanism carried by said plate and including an indicia member movable into registered position thereby; and mounting means for said mechanism comprising an uprght window member having an indicia-viewing window therein, together with a shelf portion extending angularly therefrom and having locating and attaching means cooperable with complementary locating and attaching means on said base foot portion for aligning said drum and indicia thereon before said window; and
  • mounting means for mounting a plurality of said mechanisms side-by-side, each in a predetermined spaced relation before one of said sight openings, said means comprising: a chassis for each said mechanism characterized by the provision of an upright plate member on which a said indicia member is mounted for indicating movement, and a supporting foot having spaced "apart thereon, in a direction to be normal to said sight opening, a lug slot and a set screw; and a bracket comprising an upright wall member having a plurality of sight openings formed therein and a horizontal shelf plate beneath said openings near the bottom of said wall member with a lug aligned with each said opening, and a set-screw slot aligned with each said lug and opening into an edge of the shelf plate remotely opposite the appertaining log and window, each said lug and set screw being respectively adapted to engage the lug-slot and set screw of one of
  • a high-speed stepping mechanism comprising a base plate, a ratchet wheel journalled on said plate for rotation about an axis normal to the plane of the plate; a light-weight elongated pawl of synthetic material of the class of nylon and having spaced along its length a pair of oppositely laterally projecting fingers, one of said fingers being located near a first end of the pawl and the latter having an elongated portion extending beyond the other one of said fingers in the direction of the opposite end of the pawl, said first end having formed thereat a driving tooth for driving engagement with the ratchet wheel; a plurality of guiding lugs struck up from said base plate to lie on opposite lengthwise sides of the pawl, at least one of said lugs on each side of the pawl having an elongated slot therein paralleling the direction of length of the pawl, each of said fingers projecting into the slot of one of said guide lugs on the appertaining side of the pawl, whereby the latter is slideably guided
  • a step-by-step ratchet-driven indicating mechanism comprising a hollow cylindrical indicating dial having a hub structure at one axial end thereof and a free peripheral indexing margin at its other axial end; a ratchet wheel rotatable about the axis of rotation of the dial and drivingly interconnected with the hub structure of the latter; an elongated driving pawl having a driving portion at one end and means mounting said pawl with said driving end drivingly engageable in the teeth of the ratchet wheel within the dial by movement along a second axis normal to said first-mentioned axis of rotation, and to the peripheral cylindrical face of the dial and of a length to extend a substantial distance outwardly beyond said dial face, said pawl having a substantial loop directed laterally of 1 the long axis of the pawl and of a dimension and shape to fit freely around said peripheral index margin thereof in all reciprocatory movements of the pawl; and drive means for imparting reciprocatory movement to the pawl and incinding an electromagnetic driver located

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Transmission Devices (AREA)

Description

Nov. 20, 1962 Filed Nov. 7, 1958 F. G. NICOLAUS STEPPING SWITCH MECHANISM 3 Sheets-Sheet 1 INYENTOR. Mcolazz 5 Nov. 20, 1962 F. G. NICOLAUS STEPPING SWITCH MECHANISM 3 Sheets-Sheet 2 Filed Nov'. 7, 1958 w mm 5w MN I G k n m swig Nov. 20, 1962 F. G. NICOLAUS STEPPING SWITCH MECHANISM S Sheets-Sheet 3 Filed Nov. 7, 1958 lDD INYENTOR. Fran/e G Nzcolaus Aziorn ey United States 3,9645%?1 STEPPING SWHEH MECHANISM Frank G. Nicolaus, Chicago, Elli, assignorto Lion lvfiangnfactnring Corporation, Chicago, iii, a corporation of Illinois Filed Nov. 7, 1958, Ser. No. 772,5h
13 Claims. (Cl. 2351Il7) The improvements disclosed and claimed herein relate to stepping switches, indicators, and like step-by-step ratchet-actuated mechanisms, the principal features of novelty being the provision of a compact mechanism of this class having certain ratchet mechanism located more or less interiorly of a rotable indicating drum, with a driving solenoid situated outside the drum, and a special stepping pawl having portions disposed both interiorly and exteriorly of the drum by an offset construction turning around an edge of the drum for coupling with the external solenoid.
Another feature resides in utilizing said pawl for the dual functions of stepping the drum and indexing or stopping it at an exactly registered position during each operating cycle of the pawl.
Additional features relate to the provision of a mounting means for a plurality of the stepping units so contrived that each unit is removably positionable in an exact position relative to its own display window before which the indicia on said drums will be positioned in exact registry owing to the exact stopping action of the indexing pawl means Still further features relate to the construction and operation of the combination stepping and indexing pawl means with respect to special guiding and bearing means therefor formed as a part of a chassis or base plate, together with a novel means for coupling the pawl to its solenoid plunger.
Additional objects and aspects of novelty and utility will appear as the following description proceeds in View of the annexed drawings in which:
FIG. 1 is a front elevation of a triplet-mounted score indicating assembly;
FIG. 2 is a horizontal section along lines 22 of FIG 1 with parts seen in plan view;
FIG. 3 is a (right) side elevation of the step-switch and dial assembly;
FIG. 4 is an elevational detail of one of the printedcircuit panels;
FIG. 5 is a vertical elevation looking inwardly on the ratchet and dial mechanism of one of the stepping units;
FIG. 5-A is a magnified fragmentary detail of the indexing action;
FIG. 6 is a transverse vertical section taken along lines 66 of FIG. 3 detailing the indexing teeth and pawl means .on one dial unit;
FIG. 7 is an operating detail based on FIG. 3;
FIG. 8 is another operating detail showing certain functional positions of only the ratchet pawl means;
FIG. 9 is a top plan detail of the novel driving and indexing pawl;
FIG. 10 is a perspective of the novel driving and indexing pawl;
FIG. 11 is a fragmentary, exploded perspective detail of the means for coupling the solenoid plunger to the pawl.
The embodiment of the invention depicted in FIG. 1 comprises three digital-countingstep-switch and dial units A, B, and C, carried on a novel mounting bracket 28' having an upset front wall 21 provided with three sightopenings 21A, 21B, 21C, each corresponding to one of the units A, B, or C disposed therebehind.
The mounting bracket, as in FIG. 2, has a bottom shelf 3,064,891 Patented Nov. 20, 1962 22 (FIG. 2) on which each of the plurality of units A, B, and C is independently and removably seated and secured.
Struck down from the front wall plate portion of the bracket (FIGS. 1 and 3) is an attaching flange 23 by' which it may be attached to the wall of a cabinet, as in an amusement game or the like, in which such counters and indicators are commonly employed in large numbers for score-indicating purposes.
A simple means is provided for seating and securing each of the units A, B, and C on the shelf plate 22, and consists, as seen first in FIG. 2, of the provision at the rearward edge of said plate, of an open-ended marginal slot 24 extending inwardly of the plate in alignment with an upset and slotted lug 25 located close to the opposite boundary (i.e. the down-turned attaching flange 23) of the shelf plate. V i
As viewed in FIGS. 2 and 3, each of the individual step switch and indicator units A, B, and C is provided with a chassis plate or base in the form of a one-piece stamping consisting of a main upset along its bottom margin (FIGS. 2 and 3) a bottom or foot flange 31 and al-ong its side margin a back wall or flange 32.
Means for locating and removably securing the chassis plates on the mounting bracket includes, as in FIG. 3, the provision on the foot or bottom flange 31, of a stud-like member such as the screw 31X fitting in the shelf slot 24, and spaced therefrom a slot 31Z interfitting with the shelf lug 25, and the latter, with screw 31X, provides a slip-on mounting means making it easy and quick to remove individual stepper units.
A further aspect of the locating means includes the provision of a spacer lug 33 (FIGS. 2, 3, and 7) formed as a forward projection from each main chassis plate 30, and of a size to abut the inside face of the vertical mounting bracket plate 21 to locate each stepper unit exactly at the same distance from the corresponding Window 21A, 21B, 210. This locating means greatly expedites the installation of individual units in manufacture and in servicing The step-switch and indicating dial mechanism, as viewed in FIGS. 3 to 6, includes a spindle 39 (see also FIG. 2) suitably staked into the vertical chassis plate 30, and upon which is rotatably received a hub assembly, such as shown in FIG. 5, and consisting of a molded cam member 44 having formed as an integral part thereof a set of ratchet teeth 41 (FIG. 8 also), and on a side there of opposite from said teeth at least two tapped posts 42 indicated in dotted lines in FIG. 8 and one of which is seen in full lines in FIG. 2. i
Mounted on posts 42, as by screws 43 (FIGS. 2 and 5 particularly), is a duet of spring contact fingers 44, adapted to bear upon the contact =buttons" at 45 arranged upon a printed-circuit panel 46, such as shown in FIG. 4, and which is mounted on the upright chassis plate portion 21, as in FIG. 3, in confrontation with said contact fingers. The hub structure, except for the screws and contact fingers, is preferably made from a synthetic moldable material of the class of nylon or the like.
Attached to the outside face of the hub structure, as by screws 48 (FIGS. 2 and 3), is a small, light-Weight plastic number dial or drum 50 having digital indicia about its outside periphery, as for example the numerals 0 to 9,
to be displayed and viewed through windows 21A, 21B,
21C, said numerals being selectively exhibited by stepping the drum through the special pawl and indexing means new described.
The ratchet gear, as seen in FIG. 8, is provided with ten teeth 43 each corresponding to one of said numerals on the drum, and the ratchet is stepped by means of the plate portion 30 having" install and peculiarly shaped pawl depicted in FIGS. 8, 9, and 10, the same being a one-piece molded member, preferably formed of nylon.
Referring to FIG. 9, the pawl 60 is a somewhat elongated member having a decided laterally offset bight 61 formed in its mid-region. This bight is of approximately U-shape in configuration, and strengthened externally =by ribs 62 and on its outside face has a finger stud 63 for manual stepping and resetting.
'As seen best in FIGS. 9 and 10, a special index tooth 64 is provided on the inside of the bight near the righthand or trailing end of the pawl, the purpose of which will appear more fully hereafter.
At the left-hand end of the pawl is an integral, pendant spring-attaching lug 65, and just above it, a stepping tooth 66, while nearer the bight is an integral, upstanding guide finger 67.
The right-hand end of the pawl is rounded and pierced, as at 68, for coupling by novel means with a driving member such as the plunger 74 of an electromagnet 70 mounted by means of a screw strap 71 on the rearward flange 32 of the chassis plate (FIG. 7).
The coupling means between the pawl and driving plunger is illustrated in FIG. 11 and consists in the provision of a longitudinal slot 75 in solenoid plunger 74 and a transverse pin hole 76 to receive a pin 77 which will traverse the pawl hole 68 when the appertaining end of the pawl is inserted in said slot 75.
Formed circumferentially about the plunger 74 at the pin hole 76 is a wide annular seating groove 78 of a size to receive a thin plastic collar 79 split as at 79X and adapted to fit easily into said groove after the retaining pin 77 has been inserted.
The aforesaid coupling arrangement has the advantage of great simplicity and efficiency in assembly and in operation, it being especially important that the collar 79 serves the purpose of removably securing the pin 77 and acting as a bearing for the free end of the plunger, and at the same time, owing to the split 79X, permitting free lateral or rocking motion of the attached end of the pawl, by reason of which the driver end of the pawl is considered to be provided with a floating type of bearing.
In the highly developed state of the art of stepping switches and like devices it is well-known to provide accurately-operating stepping mechanisms, which are also capable of highspeed operation, as notably in the telephone switching arts. However, such mechanisms are precision made and expensive, and frequently also complicated and involve more or less delicately or sensitively adjusted parts.
While it is contemplated that the mechanisms afforded by the present disclosures are useful in connection with the more costly class of equipment, they are intended for application to less expensive units capable of giving accurate performance at speeds considerably higher than those heretofore available for cheap mass-produced stepping mechanisms.
The advantages of the new construction result from the shape, material, mounting, and coupling of the pawl means in particulars partly set forth above and now further pointed out in view first of FIGS. 3 and 5, wherein it will be observed that the pawl 60 is attracted to a normal position toward the left (FIG. 3) by means of a traction spring 80, one end of which is engaged with pawl finger 65 and the other end of which is anchored, as to a lug 81 on the chassis stamping.
'FIG. 8 illustrates the normal, spring-urged position of the pawl, in which condition it will be observed that the pawl tooth 66 is fully flush against the engaged ratchet tooth 41A. The driving stroke of this pawl is effected by spring 80 further tensioned by energization of solenoid 70 carried on an outboard bracket 71 (along with switch 100) on chassis flange 32. This driving action is illustrated in FIG. 7.
In its reciprocable driving and retracting movements,
the pawl 60 is freely but accurately guided by stationary guiding formations which are integral parts of the chassis stamping, of which there are two below, and one above, the pawl, as depicted in FIGS. 7 and 8.
The upper stationary guide means is in the form of a wide lug 83 having a long slot 84 (FIG. 2) in which the upper end portion of the pawl guide finger 67 works easily.
Beneath the pawl is another offset chassis guide lug 85 substantially identical to lug 83, and guidedly receiving the pendant spring finger 65 of the pawl, and in FIG. 8 it will be noticed that the bottom of the pawl rides on the lug 85 in the normal position and at the terminal part of the driving stroke, whereas, according to FIG. 7, during part of the retractive stroke, the pawl is free rock upwardly so that driving tooth 66 can slip behind the next successive ratchet tooth 4113, as in FIG. 7.
In the retractive stroke, as last described above, the pawl is cocked upwardly to engage the succeeding tooth 41B by biasing action and location of the spring 8% owing to the fact, apparent in FIGS. 3 and 5, that the spring anchoring lug 81 is located somewhat above the level of its attachment to the depending spring finger 65 on the pawl, by reason of which the outer free end regions of the pawl tend to be lifted and are lifted as the pawl passes'from the last driven tooth to the next higher one.
There is a further support for the pawl in the form of a third chassis lug 86 struck out from the chassis plate 30 at the same level as the other lower lug 85 and located approximately beneath the coupled end of the solenoid plunger. 7
As in FIG. 2 at 86X, the pawl tends to ride on lug 86 in all movements and to float guidedly in relation to the slotted portions of the other two lugs 83, 85; and to rest at certain times upon the outer, lower lug 85.
The combination of a pawl formed of an effective and light bearing material such as nylon, and lugs 83, 85, and 86 arranged as described and Serving both in constraining and supporting capacities, permits the pawl to move very easily and freely, yet with decided accuracy.
A further feature of great importance relates tothe indexing or stopping of the ratchet-driven mechanism at exactly the same position on each stroke. In prior devices of this class poor and sporadic registry is a source of great trouble both in switching and indicating'operations, and much of the expense associated with the manufacture of more accurate stoppers is concerned with the problem of achieving consistently accurate steps at the highest speeds obtainable for the type of construction specified.
The present disclosures achieve commercially significant results in registry by providing axially-projecting stop or indexing teeth 58X (FIG. 6) on one axial margin of the number drum 50, each tooth corresponding to one dial numeral and therefore one stopping position.
The drum 50 is preferably formed of molded plastic aifording the greatest strength with least weight, and the drum is of a diameter and length (axially) and is so ournalled on spindle 39 that its circumferential web fits into the offset bight portion 61 of the driving pawl, as illustrated in FIGS. 3, 5, and 6, particularly.
Thus, what may be termed as axial rim portion of the light-weight dial drum 50 rotates in the offset curveor bight 61 of the driving pawl, and the indexing teeth; 50X are distributed about this rim and likewise travel: through the jog or offset 61 of the pawl and in relation to the indexing stop tooth 64 on the pawl in such manner that as pawl 60 approaches the endof each driving stroke, which causes the drum to rotate the distance of one of its teeth 50X, the pawl tooth 64 will be moving into position beneath the downwardly-advancing drum tooth 50X so as to be struck bythe latter just as the pawl comes to rest in its normal position. This indexing and stopping action is illustrated in FIGS. 5 and 6, noting particularly the drum tooth at 50XZ in both views.
In order to procure uniform positioning of each dial number in stopped position relative to the viewing window, the loading or impact face of each tooth 50X is cut flat and parallel to the center line CL (FIG. 5) and is not cut on a true radius through the center of the drum. Thus, the full area of this leading edge of the tooth falls fiat on the flat surface of pawl tooth 63 (FIG. 5A) instead of on a relatively sharper (and more variable and wearable) knife-edge, such as will occur where the tooth face is very narrow and formed on a radius.
In addition to the commutating switch action resulting from travel of the spring wiper fingers 44 over the contacts on panel 46, further control switch action is afforded by provision on the molded hub structure of certain cam-lobe and dwell formations 9t 91 (FIGS. 5 and 8 particularly).
In FIG. 8 there is seen a pair of metal switch pawls 92, 93 mounted on a common pivot 94 suitably staked into the chassis plate and respectively urged by the two arms 95, 96 of a common spring 97, on said pin and seen in dotted lines in FIG. 7. The nose of pawl 92. rides on the cam, and this pawl has a tail lever 92A disposed to project and alternately engage the blades of switch 160 and actuate the same in accordance with whether the pawl is riding the lobe 90 or dropped into the dwell 91.
The companion pawl 93 is situated to have its nose ride the teeth of the ratchet Wheel and this pawl serves the purpose of holding the ratchet, cam, and drum against displacement While the driving pawl and indexing means is in action.
The novel stepping unit is shown in FIG. 3 approximately to the actual scale of one of its commercial embodiments, together with a mounting bracket and positioning means capable of seating three such units for counting and indicating in one-digit steps from zero to 999.
Consistent performance of the described mechanism has been sustained for long periods at a rate of steps per second without error either as to positioning of the number dial or stepping on a proper switch contact, and while certain substantial economies in cost of manufacture actually have resulted from the special construction of the stepping pawl means and the drum-indexing feature, the best reliable speed of which a comparably constructed and costed stepping unit of the best prior construction is capable is about eight steps per second over a period of time of shorter trouble-free duration, there being a tendency of the prior devices when pushed to higher speeds to break down and make indexing and switching errors.
Actually the new stepping mechanism has been found capable of a speed much higher than 25 steps per second under preferred conditions, and at either rating the performance is considered an innovation, which is ascribable mainly to the light-weight construction and free-moving stepping and indexing operation of the drum by the novel pawl means.
The compact character of the unit is achieved in part by the rapid and accurate operation of the stepping mechanism which makes it possible to employ smaller parts made of lightweight materials, together with the fact that the ratchet gears, pawls, and switch wiper are all located substantially within the hollow of the drum, the driving solenoid is located outside of the hollow of the drum with its plunger moving along a line approximately parallel to a radius of the drum axis and in confrontation to the cylindrical face of the drum. These latter features in turn are made possible by the provision of the lateral jog, loop, or offset in the pawl, which bends the pawl, in a manner of speaking, around the edge of the drum and in so doing also provides for indexing or stopping coaction between the pawl and drum teeth as a function of the terminal portion of each stepping stroke.
6 I claim: 1. In a step up mechanism, a driven dial of predetermined diameter, a ratchet gear of lesser diameter than said dial, a stepping pawl reciprocable to step said gear,
electromechanical means for reciprocating the pawl; said driven dial member being rotatable coaxially with said gear,
and having a peripheral margin circumarnbient of,
and radially spaced beyond, all radial peripheral margins of the gear,
said peripheral margins being provided with stop teeth along said margin travelling in a path concentricaily of the rotative axis of the gear and driven dial member,
and located in relation to said pawl for stopping abutment with a part on the latter in a condition and position of approximate rest of the pawl near the end of its advancing stroke,
whereby each stepping operation of the pawl also includes a stopping operation by engagement of said part thereof with one of said stop teeth along the dial margin to arrest the driven dial member at a predetermined position in each stepping advance thereof.
2. Mechanism according to claim 1 in which said driven rotatable dial member is a cylindrical drum and has a hollow portion subjoining its rotative axis, and said ratchet gear and a substantial portion of said pawl are dis.- posed in substantial part in said hollow portion, and said pawl has an offset portion jogging around said peripheral margin of the drum to the exterior thereof for driving connection with said electromechanical means.
3. Mechanism according to claim 2 further characteriZed in that said electromechanical means includes a solenoid located exteriorly of the drum with a reciprocable plunger moving along a line opposite the cylindrical face of the drum.
4. Mechanism according to claim 1 further characterized by the provision of a chassis structure including a base plate and means for journalling said ratchet gear and dial member thereon, together with upset portions on said base plate for confining, guiding, and supporting, at least in part, said pawl in a path of reciprocation in operative relation to the racthet gear and dial member.
5. The construction defined in. claim 4 further characterized in that said offset pawl-guiding chassis portions are located on opposite sides of the pawl in along the line of reciprocatory motion thereof, and said pawl has at least one laterally offset finger projecting from said opposite sides thereof and at least one of said guiding formations on each side of the pawl is provided with a slot in which an appertaining one of said pawl fingers is freely movable in reciprocatory travel of the pawl to constrain the pawl to a predetermined path of travel relative to the ratchet gear.
6. in a step-up mechanism, a ratchet gear having connected thereto a hollow drum rotatable coaxially thereof with the gear disposed in the hollow thereof; a driving pawl and means mounting the same for reciprocatory motion in unidirectional driving relation with said ratchet gear, electromechanical means including a solenoid having a plunger reciprocable to drive said pawl unidirectionally by action along the line of reciprocation of the pawl but outside of the drum, said pawl having one end portion disposed in said drum hollow for driving engagement with the ratchet gear, and an opposite end portion projecting outside of the drum hollow past an axial end of the drum and radially beyond the peripheral face thereof for connection with said solenoid plunger, and means rockably, drivingly interconnecting said pawl end and plunger.
7. In a step-up mechanism, a ratchet gear and dial drum turned thereby; a reciprocable pawl means driving said ratchet gear and having a laterally offset loop extending around an axial edge of the drum; index stop teeth on said drum edge located to engage a stop formation subjacent to saidloop in a predetermined normal position of rest of the pawl; said pawl and drum being constructed and relatively positioned such that, when both the drum and pawl are in motion concurrently, clearance is provided between said index teeth and stop formation, but one said index teeth always strike said stop formation as the pawl and drum come to rest at the end of each drum-stepping operation of the pawl, whereby the drum is accurately stopped by the same instrumentality employed to drive it.
8. In a step-up ratchet mechanism, a rotatable stepping ratchet gear, a hollow drum rotated coaxially with said gear, and stepping means including a stepping solenoid located outside said drum and having a plunger reciprocable in a direction toward the drum and transversely of its rotational axis, and a stepping pawl connected at one end outside the drum to said plunger and having an opposite end region turned around an edge of the drum with a stepping tooth located interiorly of the drum for driving coaction with said ratchet gear along an axis aligned with the axis of reciprocation of said plunger.
9. In a step-up mechanism, a base plate having a foot portion on which the plate can rest in upright position; stepping mechanism carried by said plate and including an indicia member movable into registered position thereby; and mounting means for said mechanism comprising an uprght window member having an indicia-viewing window therein, together with a shelf portion extending angularly therefrom and having locating and attaching means cooperable with complementary locating and attaching means on said base foot portion for aligning said drum and indicia thereon before said window; and
means forming an integral part of said base plate and projecting therefrom a predetermined distance in a direction laterally outward of the drum axis for engagement with the inside face of said window member for locating said base plate and therefore said drum a predetermined distance away from said window.
10. For use with indicating mechanisms having movable indicia-bearing members adapted to be viewed before sight-openings, mounting means for mounting a plurality of said mechanisms side-by-side, each in a predetermined spaced relation before one of said sight openings, said means comprising: a chassis for each said mechanism characterized by the provision of an upright plate member on which a said indicia member is mounted for indicating movement, and a supporting foot having spaced "apart thereon, in a direction to be normal to said sight opening, a lug slot and a set screw; and a bracket comprising an upright wall member having a plurality of sight openings formed therein and a horizontal shelf plate beneath said openings near the bottom of said wall member with a lug aligned with each said opening, and a set-screw slot aligned with each said lug and opening into an edge of the shelf plate remotely opposite the appertaining log and window, each said lug and set screw being respectively adapted to engage the lug-slot and set screw of one of said indicating mechanisms to align the indicia member with the corresponding sight opening; each said upright chassis member having a projecting finger adapted to engage said bracket wall member to space the corresponding chassis the same predetermined distance from the corresponding sight opening.
ll. A high-speed stepping mechanism comprising a base plate, a ratchet wheel journalled on said plate for rotation about an axis normal to the plane of the plate; a light-weight elongated pawl of synthetic material of the class of nylon and having spaced along its length a pair of oppositely laterally projecting fingers, one of said fingers being located near a first end of the pawl and the latter having an elongated portion extending beyond the other one of said fingers in the direction of the opposite end of the pawl, said first end having formed thereat a driving tooth for driving engagement with the ratchet wheel; a plurality of guiding lugs struck up from said base plate to lie on opposite lengthwise sides of the pawl, at least one of said lugs on each side of the pawl having an elongated slot therein paralleling the direction of length of the pawl, each of said fingers projecting into the slot of one of said guide lugs on the appertaining side of the pawl, whereby the latter is slideably guided and retained for driving reciprocation relative to the ratchet wheel and engagement of the driving tooth therewith; a traction spring attaching with a first one of said fingers adjacent said driving tooth and pulling the pawl to engage the' tooth with the ratchet wheel to advance the latter, and means for reciprocating the pawl including a solenoid disposed at the end of the pawl remote from said first finger and having a plunger drivingly attached to said last-mentioned pawl end in alignment with the reciprocatory axis thereof and energizable to retract the pawl from said wheel with said spring driving the pawl in the reverse direction to advance the ratchet wheel on deenergization of the solenoid; and pawl means engaging the ratchet wheel to prevent retrograde motion thereof.
12. A step-by-step ratchet-driven indicating mechanism comprising a hollow cylindrical indicating dial having a hub structure at one axial end thereof and a free peripheral indexing margin at its other axial end; a ratchet wheel rotatable about the axis of rotation of the dial and drivingly interconnected with the hub structure of the latter; an elongated driving pawl having a driving portion at one end and means mounting said pawl with said driving end drivingly engageable in the teeth of the ratchet wheel within the dial by movement along a second axis normal to said first-mentioned axis of rotation, and to the peripheral cylindrical face of the dial and of a length to extend a substantial distance outwardly beyond said dial face, said pawl having a substantial loop directed laterally of 1 the long axis of the pawl and of a dimension and shape to fit freely around said peripheral index margin thereof in all reciprocatory movements of the pawl; and drive means for imparting reciprocatory movement to the pawl and incinding an electromagnetic driver located exteriorly of the dial opposite said peripheral face thereof and having a driving part operatively connected to the remaining free end portion of the pawl outside of the dial and exerting a driving thrust substantially in linear alignment with the said second axis lengthwise of the pawl.
13. The construction set forth in claim 12 further characterized in that said dial has indexing teeth on said free indexing margin thereof, and said pawl has an indexing stop formation located thereon to move along a path substantially parallel with said second axis toward and into the path of angular travel of said indexing teeth with the dial in stepping advance thereof to be struck by one of said indexing teeth'at a time close to the end of the driving stroke of the pawl and the stepping advance'of the dial whereby to arrest the dial itself always at a predetermined index position. 7 7
References Cited in the file of this patent UNITED STATES PATENTS 1,307,369 Messiter June 24, 1919 2,073,983 Anderson Mar. 16, 1937 2,244,601 Barth June 3, 1941 2,559,723 Litrell July 10, 1951 2,654,234 Christensen Oct. 6, 1953 2,789,764 Fray Apr. 23, 1957 2,810,522 Loefiier et al. Oct. 22, 1957 2,904,250
Allebach Sept. 15, 1959
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3217984A (en) * 1960-04-28 1965-11-16 Victor Comptometer Corp Sectionalized, solenoid-actuated calculating machines
US4536626A (en) * 1984-06-01 1985-08-20 The Singer Company Timer drive mechanism

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US2073983A (en) * 1932-05-17 1937-03-16 American Telephone & Telegraph Registering system
US2244601A (en) * 1939-07-25 1941-06-03 Philco Radio & Television Corp Positioning mechanism
US2559723A (en) * 1947-05-21 1951-07-10 Anthony R Litrell Signaling counter
US2654234A (en) * 1950-04-15 1953-10-06 Niels A Christensen Coupling
US2789764A (en) * 1953-03-30 1957-04-23 Fray Victor Hill Counting apparatus for cold forging machines and the like
US2810522A (en) * 1954-04-29 1957-10-22 Mc Graw Edison Co Counter
US2904250A (en) * 1955-09-06 1959-09-15 Northrop Corp Bi-directional counter mechanism

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Publication number Priority date Publication date Assignee Title
US1307369A (en) * 1919-06-24 Integrating mechanism
US2073983A (en) * 1932-05-17 1937-03-16 American Telephone & Telegraph Registering system
US2244601A (en) * 1939-07-25 1941-06-03 Philco Radio & Television Corp Positioning mechanism
US2559723A (en) * 1947-05-21 1951-07-10 Anthony R Litrell Signaling counter
US2654234A (en) * 1950-04-15 1953-10-06 Niels A Christensen Coupling
US2789764A (en) * 1953-03-30 1957-04-23 Fray Victor Hill Counting apparatus for cold forging machines and the like
US2810522A (en) * 1954-04-29 1957-10-22 Mc Graw Edison Co Counter
US2904250A (en) * 1955-09-06 1959-09-15 Northrop Corp Bi-directional counter mechanism

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3217984A (en) * 1960-04-28 1965-11-16 Victor Comptometer Corp Sectionalized, solenoid-actuated calculating machines
US4536626A (en) * 1984-06-01 1985-08-20 The Singer Company Timer drive mechanism

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