US2369513A - Control mechanism - Google Patents

Description

1F85- 13, ,1945- v. F. ZAHODIAKIN 2,369513 CONTROL MECHANISM Filed March 7, 1941 3 sheets-sheet 1 mv L Q /BQQD ATTOR EY hhhr I m m 1w@ 'AMA Feb. 13, 1945.

V. ZAHODIAKIN CONTROL MECHANISM Filed March 7, 1941 Y 3 Sheets-Sheet 2 EMM-m n INVENTOR. Af/OD/,qK/N.

A'I'TORNE'Y Feb 13, 1945- v. F. ZAHODIAKIN CONTROL MECHANISM 5 Sheets-Sheet 3 Filed March '7, 1941 N. p R. f m mM m N O .sh o" b. w D T m 0 N n H h A hn L .QN u'l km w 1@ m M tfulf. YN h l I! Q II- 1 l. E `hm `h `hh N 1cm n NN .QN W ,w .wm

Patented Feb. 13, 1945 UNITED STATES "PATENT GFF'ICE CONTROL MECHANISM Victor F. Zahodiakn, Maplewood, N. J.

Application March 7, 1941, Serial No. 382,127t

s claims. (o1. 'r4-569) l This invention relates to improvements in con Among the principal objects which the present invention has in view arez' to provide an improved control mechanism to functio-n as an interceptor or stop for a reciprocable member; to provide such a stop iii-conjunction with a con stant stroke-actuating prime mover without stopping the prime mover; to assure prompt and effective stopping of the reciprocation of the reciprocable member as desired; to denitely clear the reciprocable member from engagement with the prime mover when the reciprocable member is caused to stop reciprocating; to transfer clearance available for introducing the interceptor to function as the clearance for the prime mover; to entirely retract the interceptor from the path of movement of the reciprocable member while said member is reciprocating; to provide a brief4 dwell of interceptor with clearance between the stop and reciprocable member before transfer of the clearance to the relation of said member to the prime member; to provide a stop having both slidable and rotatable movement; to precede the rotary and slidable movement with a non-rotating slidable movement of the interceptor or stop; to provide simple and effective means for performing the sliding and the sliding and rotating movement of the interceptor or stop; to employ a solenoid for effecting said movements; to translate the sliding moment of force of the solenoid into the desired rotating and sliding movement for the desired portion of stroke of the interceptor; to incorporate means for manually operating the said interceptor `with the aforesaid movement whendesired or in event of failure of the solenoid; to obtain simple operation and construction; and to obtain other advantages and results as may be brought out in the following description.

Drawings Figurezl is a longitudinal vertical sectional View of a control mechanism embodying my invention, showing the interceptor in its unlocked position;

Figure 3 a vertical elevation ofthe reciprocable member looking at the same from a direction at right angles to the direction of .observationof .Fig. -1, and showingv the` same unlocked relation of the interceptor as in Figs. 1 and 2;

Figure 4 is a fragmentary longitudinal vertical section similar to Fig. 1., showing the interceptor in its entering position with respect to the reciprocable member;

Figure 2 is a fragmentary horizontal sectional Figure 5 is a sectional view similar to ll,`

showing the interceptor in locked position;

Figure 6 is an elevation similar to Fig. 3, but with the interceptor in locked position of Fig. 5 and showing the clearance transferred to be effective between the reciprocable member and prime mover;

Figure 7 is a longitudinal v'ertical section similar to Figure 1 and showing a modified construction introducing a second solenoid for eiecting clearance of the reciprocable member andprime mover and for situating the reciprocable member in position to receive the interceptor but not yet intercepted;

Figure 8 is a sectional-elevation at right angles to Figure 7 showing the same relation of the reciprocable member and interceptor;

Figure 9 is a section similar to Figure 7, with the reciprocable member ready to be intercepted or locked;

Figure 10 is a similar section with the reciprocable member locked;

Figure 11 is a similar section showing the reciprocable member locked and the circuits to the solenoids broken;

Figure 12 is a section similar to Fig. 9 showing an interceptor of modied construction; and

Figure 13 is a perspective view of the interceptor as shown in Figure 12.

Description There are often instances of reciprocation of a member wherein it is desired to interrupt or stop the stroke of reciprocation of such member. One such instance is in connection with the trigger or tripping mechanism of machine guns, and the present invention relates generically to the control mechanism applicable to any of the numerous apparatuses where a control of the stroke is desired. The present invention inheres in parts associated with a reciprocable member by which the member is susceptible to being stopped and with which is associated mechanism for intercepting or 'stopping such stroke- One specific ernbodiment is illustrated more particularly in Figures 1 to 6 in which reference numeral l5 desig-l nates in general a reciprocable member. The upper and lower end portions of said member are shown as aligned cylinders or rods I6 and I1 integrally connected by an intervening yoke portion IB. The reciprocable member is carried in a suitable housing appropriately shaped to provide an upper bearing portion I9 for the upper rod portion I6 of the reciprocable member and a lower bearing portion 20 for the lower end portion I1 of said member. The member is permitted to have a reciprocation within said bearings, but is prevented from rotating by suitable means such as key-way 2i situated longitudinally of the lower rod portion I1 engaging a corresponding longitudinal spline 22 in the housing. The upper end of the reciprocable member I is shown connected by a wire or other connecting means 23, which is preferably exible, to the particular device to which controlled reciprocation is to be applied. A spring 24 is diagrammatically shown in connection with said connecting means 23 which tends to actuate the reciprocable member at all times towards the upper end of its stroke. The spring is to be understood as any tensioning means either incorporated in direct association with the connection 23 or forming part of the apparatus to which the control mechanism of the present invention is applied.

In associationv with the reciprocal member I5 is a prime mover 25, here shown as a Constantly rotating shaft transverse to the reciprocable member I5 and projecting through the yoke I8 thereof. Fast upon this shaft 25 is a cam 26 situated adjacent to said yoke I3 and rotatable in a plane parallel to said yoke. The said shaft and cam are constantly rotatingnunder influence of suitable motivating means (not shown), such as an electric or other motorwhile the associated apparatus is in use. At the iront of the yoke in a plane common to the plane of the cam is a roller 21 carried by a suitable bearing or stud 28 from the reciprocable member. At such time as said reciprocable member is free to respond to the tensioning of spring 24, the said roller 21 is drawn into peripheral contact with the periphery of cam 26. Consequently, as said cam rotates the reciprocable member will move upwardly under influence of the spring as the cam rotates to present its portion of diminishing diameter to the roller. As the cam proceeds to present its periphery of increasing diameter to the roller, the said member I5 is thereby depressed. The rotary action of said shaft and cam in conjunction with spring 24 will accordingly impart a reciprocating movement to reciprocable member I5 and as so far described, such reciprocation is for the full stroke which the cam is designed to impart and with the roller in constant engagement with the cam.

In the upper rod portion I6 of the reciprocable member is provided a means for intercepting or stopping reciprocation of the said member I5 notwithstanding the continued and constant rotation of the prime mover. The means here shown contemplates the introduction of an interceptor or stop 29 as a limiting factor which is interposed in the path of movement of the reciprocable member. The; speciiic limiting factor or interceptor here shown is the end of a bolt-like slidable and rotatable member 29 transverse t0 the reciprocable member I5. While the bolt-like interceptor 29 is generally cylindrical, its end portion next the recipr-ocable member I 5 has a peripheral flattened area 3) which, when the intercept'or is in re-y tracted position as in Figures l, 2 and 3, is horizontal and at the bottom of the interceptor. The

. reciprocable member.

dimension of this flattened area in a direction longitudinal of the interceptor is preferably substantially equal to the length of the stroke of the interceptor. The reciprocable member I5 is recessed or notched, as at 3|, on its side toward the interceptor. The depth of the notch in a radial direction of the reciprocable member is also substantially equal to the length of stroke of the interceptor, and its dimension longitudinally of said reciprocable member is substantially equal to the full diameter of the interceptor. Accordingly, as can be best seen in Figures 1, 3 and 4, as the reciprocable member assumes a position with its notch 3l opposite to or in registration with the interceptor, the attened area 30 thereof affords a clearance 32 for easy entry of the interceptor end into the notch.

The interceptor is movably mounted in a lateral extension 33 of the housing, and is controlled in its character of movement by a fixed stud 34 mounted in said housing and extending diametrically through the interceptor. The interceptor receives the stud in a slot 35 the forward portion of which is longitudinal of the interceptor to constitute a dwell portion 36. Movement of the interceptor while the dwell portion 3B of the slot rides on the stud, will be strictly a straight longitudinal sliding motion whereby the ilattened area 30 at the forward under edge part of said interceptor moves, without turning, into the notch 3l of the reciprocable member. Thus I take advantage of the clearance afforded by flattening the end portion of the bolt to assure easy insertion of the interceptor. Back of the dwell portion of the slot, the same curves spirally and accordingly advancement of the interceptor then results in a combined forward sliding and rotation of the interceptor. Since the interceptor has gained foothold in the notch, the further advancement and rotation ofthe interceptor reduces the clearance of the interceptor with respect to the vertical dimension of the notch by turning the flattened area to a sidewise position and forcing the recprocable member to its lowermost position as shown in Figures 5 and 6.

The interceptor extends rearwardly a considerable distance beyond the slot and housing extension 33 and is axially coincident with a solenoid coil 3l mounted therearound and supported from said housing extension. A tubular soft-iron or other core 38 is shown carried upon the interceptor to move therewith. Inuence of the solenoid coil, when energized, is to retract the inter-- ceptor. The outer end of the solenoid is provided with a head or cap 39 which retains a xed position and forms a suitable support and guide for the protruding outer end of the interceptor. Between this cap and a suitable shoulder 40 on the interceptor is a compression spring 4I which functions to slide the interceptor inwardly toward the ccordingly, when the solenoid coil is not electrically excited, the spring functions to slide the interceptor and introduce the forward end of said interceptor` into the notch 3l the first time the notch registers with the interceptor. Prompt interception and stopping of the reciprocation of the reciprocable member is thus obtained upon opening of the electric circuit to the solenoid or upon discontinuance of the exciting current. A switch, diagrammatically shown at 42, is provided for the control of the current flow to the solenoid coil.

' In event of failure of the electric circuit or if preferred to operate the retraction of the interceptor by manual means, suitable connection 43 maybe made for that purpose. As here shown, saidiconnecton is in the form of a wirefastened having a lost-motion attachment to and extend ing from the rearmost end of the interceptor outward through a collar-like housing 44 on the outer end of cap 39. As shown, said wire or connection 43 passes through and is gripped by a contracting nut 45 screwed into a threaded bushing 46 which in turn is slidable within the end of the collar-like housing 44 and is slid inward by a compression spring 47.

I now wish to emphasize that while the Prime mover is functioning to reciprocate the reciprocable member, that is to say, while the interceptor is retracted from engagement within the notch of the reciprocable member, the roller 27 on said reciprocable member is in continuous contact with the periphery of cam 2-6 of the prime mover. Operation of that cam reciprocates the reciprocable member so that in the regular cycle of operation, the lower wall of the notch 3| is situated periodically at a level below the plane of the flattened area 3l) of the interceptor. relationship occurs with each reciprocation and when the reciprocable member is at its lowermost position in each cycle of its movement. In view of the clearance 32 provided ywhen the parts are as just described, there is no difliculty for the interceptor to engage within the notch practically immediately upon its release by the solenoid. Rotation of the interceptor transfers the clearance initially existingr between the interceptor and the notch to exist then between the peak of the cam andthe roller. Consequently, there is then no engagementof the roller with the cam at any part of its periphery, thus avoiding any clicking of the cam against the roller or any wear on the peak of the cam while thus disengaged.

From the foregoing description and inspection of thejillustrations of the structure described, it will be' appreciated that the tendency of spring 4I within the solenoid 3l is to slide the interceptor 29 and stop reciprocation of the reciprocable member. Positive action by the operator, either by closing switch Il2 to maintain electric current in the-solenoid or by pulling upon wire connection 43, is required to keep the interceptor from stopping said reciprocation. It is, however, within the scope of the invention to provide means to prevent the interceptor from sliding under impulse of the spring until action for its release is performed by the operator. A structure so operating is illustrated in Figures 7 to l1. s

Referring now to Figures '7 to 11, there is shown a reciprocable member I having upper and lower end portions IB' and Il' as before, integrally connected by an intervening yoke portion I8'. reciprocable member is carried in this instance also, in a suitable housing appropriately shaped to provide an upper bearing portion I9' for the upper rod portion I6' of the reciprocable member and a lower bearing portion 20 for the lower end portion I1 of said member. However, the structure now being described provides for protrusion of the lower end portion I1 below the housing. The'member is permitted to have a reciprocation within said bearings and Iwith the protruding lower end always outside of the housing. The upper end of the reciprocable member I5', as in the previously described construction, is shown connected by a wire or other connecting means 23', whch is preferably exible, to the particular device to which controlled reciprocation is to be applied. A spring 24' is diagrammatically shown ln connection with said connecting means 23' Thisv The f whichltends to actuate the reciprocable member at all times towards lthe upper end of its stroke. The spring is to be understood as any tensioning means either incorporated in direct association with the connection '23' or forming pari; of the apparatus to which the control mechanism' of the present invention is applied.

In association with the reciprocal member F5' is a prime mover 25', here shown as a constantly rotating shaft transverse to the recipro-cable member l5' and projecting through the yoke I8 thereof. Fast upon this shaft 25 is a cam 28. situated adjacent to said yoke I8 and rotatable in a plane parallel to said yoke. The said shaft anducam are constantly rotatingunder influence of suitable motivating means (not shofwn), such as an electric or other motor while the associated apparatus is in use. At the front of the yoke in a plane common to the plane of the cam is a roller 21' carried by a suitable bearing or stud 28' from the reciprocable member. At such time as said reciprocable member is free to respond to the ten` sioning of spring 24', the said roller 2l' is drawn into peripheral contact with the periphery of cam 2-6. Consequently-as said cam rotates the reciprocable member will move upwardly under influence of the spring as the cam rotates to present its portion of diminishing diameter to the roller. As the cam proceeds to present its periphery of increasing diameter to the roller, the said member l5' is thereby depressed.` The rotary action of said shaft and cam in conjunction with spring 214 will accordingly impart a reciprocating movement to reciprocable member I5 and as so far described. such reciprocation is for the full stroke which the cam is designed to impart, and with the roller in rconstant engagement with the cam.

In the upper rod portion l5' of the reciprocable member is provided a means for intercepting or stopping reciprocation of the said member I5' notwithstanding the continued and constant rotation of the prime mover. The means here shown contemplates the introduction of an interceptor or stop 29' as a limiting factor which is interposed in the path of movement of the reciprocable member. The specific limiting factor or interceptor here shown is the end of a bolt-like slidable and rotatable member 29 transverse to the reciprocablemember I5. The reciprocable member I5' is recessed or notched, as at 3|', on its side toward the interceptor. The depth of the notch in a radial direction of the reciprocable member is substantially equal to the length of stroke of the interceptor, and its dimension longitudinally of said reciprocable member is substantially equal to the full diameter'of the interceptor plus a clearance which is normally present at the upper end of the notch. As can best be seen in Figures 7 and 8, asthe reciprocable member assumas its lowermost position under influence lof cam 26' its notch 3|' does not lower quite far enough to be in registration with the interceptor and thus, in normal operation the interceptor rides at its end against the' edge of the-reciprQ- cable 'member and cannot enter said notch. However,`when the reciprocable member is lowered beyond its normal lowermost position, its end can and will enter the notch. v The interceptor is movably mounted ina lateral extension 33' of the housing, and its character of movement will be strictly a straight longitudinal sliding mo-tionvwhereby the forward end thereof may be impelled into the notch 3| of isters therewith. I

The interceptor extends rearwardly a suitable distance beyond the housing extension 33 and is axially coincident with a solenoid coil 31 mounted therearound and supported from said housing extension. A tubular soft-iron or other core 38' is shown carried upon the interceptor to move therewith. Inuence of the solenoid coil, when energized, is to retract the interceptor. The outer end of the solenoid is provided with a head or cap 39 which retains a fixed position and forms a suitable support and guide for the outer end of the interceptor. Between this cap and a suitable shoulder 40' on the interceptor is a compression spring 4 i which functions to slide the interceptor inwardly toward the reciprocable member. Accordingly, when the solenoid coil is not electrically excited, the spring functions to slide the interceptor and introduce the forward end of said interceptor into the notch 3|', when the reciprocable member is depressed further than under influence of cam 26 and when the notch is thereby brought into registration with the interceptor.

I now wish to emphasize that while the prime mover is functioning to reciprocate the reciprocable member, the roller 21' on said reciprocable member is in continuous Contact with the periphery of cam 26 of the prime mover. Operation of that cam reciprocates the reciprocable member so that in the regular cycle of operation, the lower wall of the notch 3l is always situated at a level above the lower forward edge of the interceptor. This relationship continues with each reciprocation until the operator performs a positive act to cause the reciprocable member to go lower than such normal lowermost position of cam operation, namely to a sub-normal lower position. In View of this lowering to sub-normal position, a clearance will then exist between the peak of the cam and the roller. Consequently, there is then no engagement of the roller with the cam at any part of its periphery, thus avoid- `ing any clicking of the cam against the roller or any wear on the peak of the cam while thus disengaged.

The particular means here shown to actuate the reciprocable member to its sub-normal lower position is a second solenoid coil axially coincident with the extended axis of the reciprocable member and located beyond the lower end of the housing for that member. The magnetic ux of this coil may be increased by having a. xed core 49 within the lower part thereof. A movable core 50 is within the upper part of the coil and is mounted upon the lower end of the reciprocable member protruding at the bottom of the housing. rSpace is provided longitudinally of the coil suicient for the movable core to have amplitude of movement both for the normal reciprocation under inuence of cam 26 and for movement of the said member to its sub-normal position.

Wiring for electric current to both solenoids is through a duplex switch I of suitable construction. As shown, a switch arm 52 is connected at its fulcrum. 53 to an indicated power line 54. Said arm is adapted to make electrical corntact with either and both of two contacts 55, 56. The first of these contacts 55, is connected by wire 51 to the first-described solenoid, that is, the solenoid which retracts the interceptor. The second of these contacts 56, is connected by wire 58 to the second-described solenoid, that is, the solenoid which retracts the reciprocable member to sub-no-rmal position. Return wires are indicated as grounded from each solenoid.

In operation, with the reciprocable member locked, as in Fig. 11, and it being desired to start reciprocation thereof, the operator swings switch arm 52 counterclockwise around to contact 55 to energize the interceptor solenoid 31 which immediately functions to withdraw the interceptor from the notch 3|'. With the circuit left closed, the interceptor is drawn back so as to not contact the reciprocable member at all. However, if it it is not desired to continue to energize the solenoid after release of the reciprocable member, the switch can be turned clockwise to open the circuit, permitting the end of the interceptor to engage the edge of the reciprocable member as heretofore described.

To stop operation, the switch arm 52 is swung again counter-clockwise engaging both contacts 55 and 56 simultaneously as in Fig. 9, thus energizing both solenoids. This frees the interceptor from the reciprocable member and assures that the solenoid for that member will lower said member to its sub-normal position, with the notch 3 I thereof directly opposite the interceptor. The switch arm is continued in its counter-clockwise turning, breaking connection to the rst solenoid but retaining connection to the second solenoid. Thus, as shown in Fig. 10, the interceptor is released to snap into the notch while the second solenoid continues to hold the reciprocable member in its sub-normal position. Next the switch arm is continued counter-clockwise to its original positionbdisengaged from both contacts, and the interceptor then functions alone to prevent reciprocation of the reciprocable member.

In Figures 12 and 13 is illustrated a construction combining features of reciprocable member wherein the notch thereof opposes the end of the interceptor in normal cycle of reciprocation as in Figures l to 6 and the reciprocable member is non-rotating somewhat similar to the disclosure of Figures 'l to 11. Accordingly in IFigures 12 and 13 is provided a reciprocable member I5" the notched rod portion I6" only of which is shown, the remainder thereof and operating Ameans therefor being identical with the showing of Figures 1 to 6. The reciprocable member I5" has a notch 3|" therein for reception of an interceptor or stop 29" slidable toward and away from the reciprocable member by spring and solenoid means as shown in Figures '7 to 11 and not deemed necessary to reproduce in said Figures 12 and 13. The interceptor is slidable in a lateral housing extension 33" and provides a longitudinal straight slot 35 riding upon a Xed stud 34" passing therethrough and secured in said housing extension. This interceptor is therefore longitudinally slidable but non-rotatable.

The forward end of the interceptor 29 of Figures 12 and 13 has stepped flattened portions at top and bottom. The most forward ilattened portions 30a are closer together diametrically of the interceptor than the more rearward ilattened portions 3%. The combined dimension, longitudinally of the interceptor, of the two attened portions is substantially equal to the depth of the notch 3I" and of the length of the slot 35" controlling the stroke of the interceptor. Forward movement of the interceptor into the notch rst introduces the forward step or attened portions 36a into the notch, and by virtue of the less dimensiony diametrically between those flattened portions than the height of the notch, a considerable clearance is provided. Consesequently the interceptor may readily enter the notchas the reciprocable member l" reaches the lower end of its normal stroke." '4 'f-After `initial introduction of the interceptor into' the notch 3|" of the reciprocable member further forwardv movement of the interceptor causes the more rearwardand more widely separated stepped flattened portions h Ato enter the notch. To facilitate this last-mentioned movement of the interceptor it is preferable to curve or otherwise slope the juncture of the first step 30a toward theusecond step 30h, as at 30c. Riding of thesecond step 30h into the notch 3l" depresses the reciprocable member below its,l no'r' mal position of strokeand thereby introduces the clearance between the operating cam and roller as above-described in connectionwith Fig-I ures'lto. v l

Inasmuch as the forward end of the interceptor, when pressed forward,` and before entry is accomplished into notch 3l", will ride against the surface of the reciprocable member, I preferably provide a flattened riding surface Sla at that part of the reciprocable member immediately below the notch. Such construction reduces wear and greater ease and accuracy of operation. The corner edge between this flattened riding surface 3|a and the bottom wall of notch 3|" is shown rounded, as at 3 Ib, thus reducing resistance of entry of the forward end of the interceptor into the notch.

1. A control mechanism comprising a housing,

a reciprocable member mounted in said housing, y

an interceptor in said housing transverse to said member, said interceptor having a flattened surface for initial engagement with the member and a rounded surface for depression of the member by rotation of the interceptor after said initial engagement is effected, said .interceptor having a control slot therein the forward part of which is longitudinal of the interceptor and the rearward part of which is spiral, and a fixed stud in the housing projecting into said slot whereby sliding the interceptor toward the reciprocable member obtains the successive straight forward initial lntercepting movement of the interceptor and thereafter the rotation of the interceptor for effecting a depressing actuation of the reciprocable member. V

2. A control mechanism comprising in combination a reciprocable member having a normal stroke and having a notch at one side thereof, an interceptor opposite said notch .and movable thereinto, said interceptor having a stepped flattened portion of which the outer step affords clearance for introduction of the outer end of the interceptor with clearance into said notch during normal stroke of the reciprocable member, and another stepped flattened portion engageable in said notch and operating to depress the reciprocable member beyond its normal stroke and transfer the clearance to another part of the reciprocable member.

3. A control mechanism comprising in combination a reciprocable member having a normal stroke and having a, notch at one side thereof, a non-rotating slidable interceptor having a stepped flattened portion at the bottom thereof and said stepped flattened portion providing an end step next the reciprocable member and a second step rearward of the end step and wherein said end step is at a greater elevation from the level of the bottom of said notch than said second step. whereby sliding said interceptor first introduces the end step with clearance into said notch and further sliding of the interceptor in. troduces the second s'tep into ysaid notch with lessclearancepj- Y v` *y 4.'A control mechanism'comprising in combination with a reciprocable member-having a normal stroke and having a notch in its side, said notch' having a surface transverseto said member for entry and engagement therein of an interceptor, and aninterceptor substantially opposite and having a part thereof freely admissible intosaid notch when the reciprocable memberfis at vone end position of its normal stroke, said freely admissible part of said interceptor having a iiat surface parallel to said notch surf face, said surfaces being juxtaposed in parallelism-during free admission of the said interceptor part intosald notch, said notch reciprocating in use into "and out of registration withvsaid interceptorwhereby the interceptor may enter the notch only at a denit'e stroke positionof the reciprocable member, and said control mechanism having means acting to retain the reciprocable member beyond said end position of its normal stroke after entry of the interceptor into said notch.

5. A control mechanism comprising in combination with a reciprocable member having a normal stroke and having a notch in its side, said notch having a surface transverse to said member for entry and engagement therein of an interceptor, an interceptor substantially opposite and having a part thereof freely admissible into said notch when the reciprocable member is at one end position of its normal stroke, said interceptor part having a surface parallel to said notch surface and said reciprocable member reciprocating in use to cause the notch surface to pass the said interceptor surface to thereby afford clearance for entry of the interceptor part freely into said notch, said surfaces being juxtaposed in parallelism during free admission of the said interceptor part into the notch, and said interceptor having another part alined parallel to the said notch surface and insertable into the notch for depressing the reciprocable member beyond the position of normal stroke.

6. A control mechanism comprising in combination with a reciprocable member having a normal stroke and having a notch in its side, said notch having a surface transverse to said member for entry and engagement therein of an interceptor, an interceptor transverse to said reciprocable member, said interceptor having its end margin freely admissible into said notch at one position of the reciprocable member, said end margin having a attened surface parallel to said notch surface, said surfaces being juxtaposed in parallelism during free admission of said end margin of the interceptor into the notch, said notch reciprocating in use into and out of registration with said interceptor whereby the interceptor may enter the notch only at a definite stroke position of the reciprocable member, and said interceptor being slidable and rotatable and insertable in said notch by sliding thereby engaging in said notch and rotatable in said notch thereby depressing the reciprocable member below the bottom position of normal stroke.

7. A control mechanism comprising in combination with a reciprocable member having a normal stroke and having a notch in its side, saidV notch having a lower face transverse `to said member for entry and engagement therein of an interceptor, an interceptor transverse to said reciprocable member, said interceptor being slidable and having its end margin freely admissible into; said notch when the rec-iprocable member is at one end position of its normal strokesaid margin having a flattened surface parallel to said lower face ofthe notch, said face and surface being juxtaposed in Aparallelism at said end position of normal stroke of the recprocable member and. with clearance between saidvface and surface enabling the interceptor flattened surface to be slid over the said lface of the notch, and said interceptor having another area movable into progressive juxtaposition to said lower lface of the notch after entry of said interceptor in said notch to depress the reciprocable member below normal stroke. 8. A control mechanism comprising in combination with a reciprocable member having a normal stroke and having a notch at one side tneref o f, said notch having its lower surface transverse ,to said member, a, slidable 'interceptor opposite notch and rotating the'interceptor subsequent t0 saidnotch when the reciprocable member is at one end position ot its normal stroke, said inter.;

ceptor having'a. portion slidably movable into reciprocable'y member, and said` interceptor bein: rotatable. after initial entry into the notch thereby depressing the-reciprocable member beyond its normalstroke, and means confining and. direct movement of the interceptor to sliding motion dlirmg initial entry of the interceptor into the such entry into the notch.

' VICTOR F., zAHoDmxn.

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