US2523740A

US2523740A - Automatic lock slider for slide fasteners

Info

Publication number: US2523740A
Application number: US574893A
Authority: US
Inventors: Ulrich Frederick; Disinger Claude
Original assignee: Conmar Products Corp
Current assignee: Conmar Products Corp
Priority date: 1945-01-27
Filing date: 1945-01-27
Publication date: 1950-09-26
Anticipated expiration: 1967-09-26

Description

3 Sheets-Sheet 1 F. ULRICH ETAL AUTOMATIC LOCK SLIDER FOR SLIDE FASTENERS 4 Q a m Inf? 53 Win Filed Jan. 27, 1945 Sept. 26, 1950 mm w m wu W w m a mw v fl W N am w Sept. 26, 1950 F. ULRICH EIAL AUTOMATIC LOCK SLIDER FOR SLIDE FASTENERS Filed Jan. 27, 1945 3 Sheets-s 2 INVENTQRS Frederic/7 V0 22d Claude ysz fliz y Sept. 26, 1950 F. ULRICH ETAL AUTOMATIC LOCK SLIDER FOR SLIDE FASTENERS 3 Sheets-Sheet 5 Filed Jan. 27, 1945 INVENTORS: 1 9 2679247423 Ulrzck Claude .Z7i5

inyer Patented Sept. 26, 1950 2,523,740 OFFICE AUTOMATIC LOCK SLIDER FOR SLIDE FASTENERS Frederick Ulrich; Jersey City, and Claude Disinger, South Plainfield, N. J., assignors to Conmar Products Corporation, Newark, N. J., a corporation of New Jersey Application January 27, 1945, Serial No. 574,893

r 18 Claims. Y 11 This invention relates to an improved automatic lock slider for slide fasteners.

Slide fasteners comprise two mating slide fastener stringers (tapes with mounted fastener elements) brought into and out of meshing or mating relation by the movement of a so-called slider through'the slide channel of which the stringers slide or move. It is necessary to provide a suitable locking device for the slider to prevent the stringers accidentally opening during use. According to one type of lock slider the locking member is made so as to be entirely automatic in its locking operation. The common form of automatic lock slider embodies a locking member on the slider which is normally held in its locking'position by a spring and which is moved against the action of the spring by a pull element connected to the locking member. Our present invention relates to an improved automatic lock slider of this type.

The prime objects of our invention center about the provision of an automatic lock slider featured by the following improvements:

1. The lock slider is composed only of three elements, namely, the slider, the locking member, and the'pull element. These three parts are so designed and constructed according to the present invention that they are capable of being most conveniently and quickly assembled.

2. To achieve this the locking member embodying its supported part, its locking detent and the spring for actuating the same is made as a unitary piece with all these parts preferably integral and preferably shaped up from sheet metal. The use of separate springs with the difficulties of handling and slider assembling incident thereto is obviated.

3. Despite the limitations imposed by the small space available on a slider, the unitary locking member is so constructed that ample operating leverages are obtained for effecting the automatic locking operation and the unlocking operation of the slider. In accomplishing this, the locking member and its mounting on the slider are so designed that the locking member leverage and the effective spring leverage each extend over a substantial, such as the greater part, of the slider length, and

4. The locking member and its mounting are so designed that the proper acting (and different) leverages are made effective for the unlocking and the locking actions of the slider, which are inherently different.

To the accomplishment of these objects and such other objects as may hereinafter appear our invention is directed to the automatic lock slider and the component combinations thereof as sought to be defined in the appended claims and as described in the following specification taken together with the accompanying drawings in which:

Fig. l is a front elevational view, with a part broken away, of the lock slider of the present invention;

Fig.2 is a view thereof taken in cross-section in the planes of the

line

2, 2 of Fig. 1 and showing the locking member'in one of its positions;

Fig. 3 is-a" front elevational view of the slider taken on a reduced scale and showing the same before the locking member is assembled thereto;

Fig. 4 is a view similar to Fig. 2 but shown on a reduced scale and showing the locking member in another of its positions;

Fig. 5 is a partial view similar to Fig. 4 and showing the locking member in still another of its positions;

Fig. 6 is a perspective view of the locking member itself,

Fig. '7 is a view corresponding to that of Fig. 2 and showing a modified form of the lock slider of the present invention, and

Figs. 8, 9 andlO are views corresponding to the views of Figs. 3, 4 and 5, but relating to this modification of the structure of Fig.- 7.

Referring now more in detail to the drawings and having reference first to Figs. 1 and 2 thereof, the invention is shown applied to a conventional slide fastener comprising the slider S provided with the interior slide channel C and the two stringers s, s, the latter each comprising a beaded tape it with the spaced slide fastener elements f, f mounted thereon, the said stringers being adapted to be brought into and out of meshing or mating relation by the up and down movement of the slider S through the slide channel C of which the stringers slide or move. The slide channel C is a Y-shaped channel as best shown in Fig. 1 through the stem of which the fastener elements move when meshed or interengaged and through the Y branches of which the fastener elements move when they are disengaged, as is most clearly shown in Fig. 1 of the drawings.

According to'one form of known structure, the slider s comprises a rear or bottom wing section 29 and a front or top wing section 22 which are secured together as by being spot welded at their upper termini and 26. The bottom wing 20 comprises a body wall provided with the inturned opposite flanges 28, and similarly the top wing 22 comprises a body wall provided with the inturned opposite slide flanges 30. These two slider wings 2c andZZ as described define the interior Y- shaped slide channel C for the slide fastener stringers. Thus far the constructiondescribed is a conventional form of slide fastener. By moving theslider downwardly, the slide fastener is'opened, and'by moving the slider upwardly, the

- slide fastener is closed.

vided with a substantially rectangular orifice 32 opening into the slider channel C, and the medial upper wall portion 34 of the front slider wing immediately above this orifice is shaped to define a mounting seat for the fulcrum and other engaging parts of the locking member. Preferably, this wall portion 3 3 is pressed out so as to be elevated slightly above the wall of the front wing 22 as is most clearly shown in Figs. 2, 4 and of the drawings.

The locking member L comprises essentially a front arm 35 and a rear arm 38 united together at their bottom ends 43 (see Fig. 2) and free at their other or upper ends, said arms being movable resiliently one with respect to the other, said locking member having at least one detent 32 adjacent its bottom end, said detent projecting into the slider channel 0. The resilient relative motion between the front arm 36 and the rear arm 38 is preferably accomplished by making one of these arms resilient; and in the construction shown, the front arm 36 is formed as a rigid element and the rear arm 38 is formed as and defines the resilient element or arm of the locking member. Preferably these three component parts of the locking member, namely, the front rigid arm 35, the rear resilient arm 38, and. the locking detent 42, comprising a unitary piece, are all integral; and this unitary piece is formed, by bending and stamping operations, into the shape best shown in Fig. 6 of the drawings. We have found that this unitary locking member may most conveniently be fashioned when made out of an alloy such as copper-beryllium, the resilient arm 38 being tempered for its resilient action after the element has been shaped into the desired form.

In its more specific embodiment the locking member L is shaped so that its front arm 36 comprises a rigid elongated cap having a front wall it and rearwardly turned

side walls

46 and 48, the resilient arm 38 being formed integral with one of the side walls, such as the side wall 46. For accomplishing other objects as will be made clear hereinafter, the other side wall 48 is formed with a rearwardly projecting finger portion 50 L- shaped so as to provide a stop element 52 and this side wall is also formed with a second detent 54, the

detents

42 and 54 being arranged in staggered relation so as to cooperate with the mating and staggered slide fastener elements of a pair of stringers with which the slider is employed. The

slide walls

46 and 48 are also shaped So as to provide the camming openings 56 and 58 for receiving the opposite prongs 60, B0, of a pendant pull device 62.

The locking member L is assembled to the slider S by merely placing the locking member into the position best shown in Fig. 2 of the drawings. This is done by inserting the rearwardly projecting parts of the locking member L into the orifice 32 of the front slider wing 22, the upper parts of the locking member L being caused to straddle the mounting wall portion 34 of the front slider wing. The assembling operation is then completed by forming a stop element in the slider to prevent the withdrawal of the locking member as will be described further hereinafter. When so assembled, the locking member L assumes the position as shown in Figs. 2 and 4 of the drawings. The mounting wall portion 34 then forms a fulcrum F1 for the rigid arm 36 of the locking member, a bearing part B for the resilient arm 38 thereof, and also a second fulcrum F2 for the rearwardly projecting finger 55 of the locking member. The wall portion 3 1 is preferably formed with a rearward inclination as best shown in Fig. 2 so as to better define these fulcrums and this bearing part, and also so as to put under a slight initial tension the resilient arm 38, the action being such that there is an initial tendency to spread the arms 35 and 33 of the locking member. With this arrangement of the parts, the locking member L is normally urged to its locking position, shown in Figs. 2 and l of the drawings, with the detents t2 and 54 ready to engage or engaging a pair of staggered slide fastener elements I, f.

The locking member L is thus, under the resilient action of its rear resilient arm 38, normally and automatically moved to its locking position as shown in Fig. 4 of the drawings. When a cross pull is exerted upon the upper ends of the stringers s, s, tending to open the stringers, the slider S tends to move downwardly relatively to the stringers thereby bringing the teeth or detents 42 and 5 3 (if they are not yet in engagement with the slide fastener elements) into locking engagement with the slide fastener elements 7, f, as is best shown in Fig. 2 of the drawings. When this takes place, the locking member L is so acted upon that its rearwardly projectin finger 50 en ages the fulcrum F2, whereby the continued action of the engagement of the slide fastener elements against the

detents

42 and 54 will cause the locking member L to tend to rock inwardly about this fulcrum F2 with the result that the locking member is forced all the more into its locking position. Thus, the proper kind of leverage is obtained with the utilizing of this fulcrum F2 to inhibit any tendenc towards an unlocking operation under the stress of a cross pull on the stringers and, on the contrary, to effect a firmer locking action under this condition. The slider is unlocked in the usual way by either a downward pull (during opening of the slide fastener) or an upward pull (during closing of the slide fastener) exerted on the pull device 62. During a downward pull thereof this pull device is moved from the position shown in Fig. 2 to that shown in Fig. 5, during which movement the prongs 6B, 60 of this pull device engage and ride over the cam openings 56 and 58, thus forcing the locking member L to move outwardly against the action of its resilient arm 38, the locking member L during this operation being moved about the fulcrum F1. As will be understood, during this operation the resilient arm 38 is under an increased deflection, the

arms

36 and 38 being spread wider apart, as best shown in Fig. 5. The fulcrum F1 provides the right kind, and also a desired length of leverage for this action. During an upward pull of the pull device 62 the prongs thereof engage the cam openings at the bend 64, and the locking member L is similarly moved about its fulcrum F1 to an unlocking position or to a position where the detents 42 and 5s freely ratchet over the slide fastener elements I, Upon manual release of the pull 62 after either a downward or upward pulling operation, the locking member L automatically returns to its locking position of Fig. 4 and the parts assume either the position shown in Fig. 4 or the firmer locking position shown in Fig. 2 when any cross pull is exerted on the slide fastener stringers.

The stop element 52 formed at the end of the rearwardly projecting finger 59 cooperates with the rear surface of the mountin wall portion 34 to limit the outward movement of the locking member L at its upper end during either manual operation of the pull device, and this stop element also serves to retain the upper parts of the locking member from being withdrawn from the slider. To similarly limit the outward movement of the bottom end of the locking member, and to prevent the same from being Withdrawn from the slider orifice after the locking member is assembled to the slider (but to permit the assembling operation first to take place) the bottom end of the locking member L is formed with two downwardly projecting fingers 6i) and 68 which define stop elements adaptedto engage with an upwardly turned flange portion H! formed in the bottom bridgin portion 12 of the front slider wing 22, as best shown in Figs. 1 and 2 of the drawings. To enable the parts to be assembled, the front slider wing, prior to the deforming step about to be explained, has its bridging portion 82 and the flange H! of the latter in the linear condition shown in Fig. 3 of the drawings. The lockin member may thereby be freely inserted and mounted in position on the slider as above described. After this is done the said bridging portion i2 is deformed by being pressed inwardly, with the result that the flange it of the bridging portion 12 is projected into the path of movement of the

stop elements

66 and 68, thereby forming therewith the means for limiting the outward motion of the bottom end of the locking member and for preventing any withdrawal of the locking member from the slider. This deforming is accomplished by a suitable tool such as the member M, shown in Fig. 1 of the drawings, which is forced into engagement with the central part of the said bridging portion 72 as is most clearly shown in Fig. 1 of the drawings. It is this deforming. operation which completes the assembling step above described. 7

The modification shown in Figs. 7 to 10 of the drawings is the same as that shown in Figs. 1 to 6 thereof except for the construction of the second set of stop means. All the parts of this modification that are similar to the parts of the construction shown in Figs. 1 to 6 are designated by similar, but primed reference characters. Instead of forming stop fingers 6B and 68 at the bottom end of the locking member and insetting the wall bridge portion 52 and its fiangelil so as to cooperate with these stop fingers, there is provided in the embodiment shown in Figs. 7 to 10, a different form of stop means comprising an inverted L-shaped tongue member 14 extending upwardly from the bridge portion l2 and'located in the orifice 32 of the front slider wing 22. This tongue, so formed, divides the orifice 32 into three channels, a channel '56 (see particularly Fig. 8) into which is projected the resilient arm 38 of the locking member, a channel l8 into which is projected the detent 54 of the locking member, and a top transverse channel 88 which receives and into which is projected the finger 5G with its stop elcmentfif. L is assembled to the slider S the tongue-piece 74 is bent or deflected inwardly from the full line position to the dotted line position shown in Fig. '7 of the drawings. This'- permits the locking member to be inserted into the orifice 3 2' and mounted in position'in the sameway as described for the structure of Figs. 1 to 6'. After this assembling step, the tongue M is returned by the When the lockin member which are inherently different.

ture. The engagement of the lower face 82 (see particularly Fig. 7) of the finger 50' with the top wall face 84 of the tongue 14, as is best shown in Fig. 10 of the drawings, limits the outward swing or movement of the locking member L on a downward pull thereof, and prevents the bottom end of the locking member from being withdrawn from its mounted position of the slider. In this form of the invention the locking member L with its pull 62' may be mounted on the front slider wing before the two slider wings are welded together, or may be mounted on the completed slider, in which latter event the tongue M is returned to its normal or full line position by the insertion into the slider of a suitable tool.

The making and using of the lock slider of the present invention and the advantages thereof will in the main be fully apparent from the above detailed description thereof. In both exemplified structural forms of the invention, the lock slider is composed only of three elements, namely, the slider S (or S), the locking member L (or L), and the pull element 62 (or 62'). These three parts are so designed and constructed that they are capable of being most conveniently and quickly assembled. The locking member is formed as a unitary piece and, preferably, its three parts, namely the locking arm 36 (or 35') the detent 42 (or 42), and its spring arm 38 (or 38) are formed integrally and preferably shaped (as are all'of the parts of the slider) out of sheet stock. This locking member is so formed and shaped that it may be readily mounted on the front wing of the slider and so that the top end of this wing forms a fulcrum mounting means and a spring arm engaging means for the locking member parts. invention the mere step of inserting the locking member in position serves to mount the locking member on the slider, it being then only necessary to deform or reform by a simple tooling operation a slider part so as to prevent the withdrawal of the locking member from its mounted position.

In the construction thus provided, despite the limitations imposed by the small space available on a slider, ample operating leverages are obtained for effecting both the automatic locking operation and the unlocking operation of the slider. Thus, the locking member and its mounting on the slider are so designed that the leverage for the locking arm 36, i. e., the leverage from fulcrum F1 to the detent such as 42 or 5 3 is an extensive one and extends over a substantial, such as the greater part of the slider length, and the leverage for the spring or resilient arm 38; 1. e., the leveragefrom the engagement or presure point B to the detent is also an extensive one and extends over a substantially similar part of the slider length. Furthermore, the locking member and its mounting are so designed that the proper acting leverages are made effective for the unlocking and locking actions of the slider Thus, for the In both exemplified forms of the unl cking action and the automatic return to the locking position the fulcrum F1 is utilized; and the leverages, just described, for the locking arm and the resilient arm, which leverages are arranged longitudinally of the slider, are effective. When, due to a cross pull on the stringers, the slide fastener elements 1, J engage the detents 32 and the fulcrum F2 comes into play, and a transversely arranged leverage is formed effective about this fulcrum to urge and move the locking member to firmer locking position.

While we have shown and described preferred forms of our lock slider, it will be apparent that changes may be made therein without departing from the principles thereof and the spirit of the invention defined in the following claims.

We claim:

1. An automatic lock slider for a slide fastener comprising, a slider body having front and rear wings spaced to provide a slider channel for the slide fastener stringers, and a locking member mounted on said front wing, said locking member comprising a front arm and a rear arm united together at their bottom ends and free at their other ends, said arms being movable resiliently one with respect to the other, said locking member having a detent adjacent its bottom end projecting into the slider channel, the free end of the front arm being fulcrumed on the slider front wing, and the free end of the rear arm being arranged for engagement by a part of said slider body so that a force applied thereto in a resultant direction transverse to said arms will move the arms of said locking member resiliently one with respect to the other to move the locking member about its front arm fulcrum to locking position, and means connected to said locking member for moving the same about its said front arm fulcrum in opposition to said force to move the locking member to unlocking position.

2. An automatic lock slider for a slide fastener comprising, a slider. body having front and rear Wings spaced to provide a slider channel for the slide fastener stringers, and a locking member mounted on said front wing, said locking member comprising a front arm and a rear arm united together at their bottom ends and free at their other ends, said arms being spreadable resiliently one with respect to the other, said locking member having a detent adjacent its bottom end projecting into the slider channel, the free end of the front arm being fulcrumed on the slider front wing, and the free end of the rear arm being arranged for engagement by a part of said slider body so that a force applied thereto in a resultant direction transverse to said arms will tend to resiliently spread said arms to move the locking member about its front arm fulcrum to locking position, and means connected to said locking member for moving the same about its said front arm fulcrum in opposition to said force to move the locking member to unlocking position.

3. An automatic lock slider for a slide fastener comprising, a slider body having front and rear wings spaced to provide a slider channel for the slide fastener stringers, and a locking member mounted on said front wing, said locking member comprising a front arm and a rear arm united together at their bottom ends and free at their other ends, said arms being movable resiliently one with respect to the other, the top free end of the front arm being fulcrumed on, and the free end of the rear arm bearing against, parts of the slider front wing, said locking member having a locking detent adjacent its bottom end projecting into the slider channel.

4. An automatic lock slider for a slide fastener comprising, a slider body having front and rear wings spaced to provide a slider channel for the slide fastener stringers, the front wing having an opening therethrough, and a unitary locking member mounted on said front wing, said locking member comprising a rigid front arm and an integral resilient rear arm united at their bottom ends and free at their top ends, the top end of the rigid arm being fulcrumed on, and the top end of the resilient arm bearing against, parts of the slider front wing, said locking member having a locking detent adjacent its bottom end projecting through the front wing opening into the slider channel.

5. An automatic lock slider for a slide fastener comprising, a slider body having front and rear wings spaced to provide a slider channel for the slide fastener stringers, the front wing being provided with an orifice, and a locking member mounted on said front wing, said locking member comprising a rigid front arm and a resilient rear arm united together at their bottom ends and free at their top ends, the top end of the rigid arm being fulcrumed on, and the top end of the resilient arm bearing against, parts of the slider front wing, the resilient arm extending into said front wing orifice, said locking member having a locking detent adjacent its bottom end projecting through the front wing orifice into the slider channel.

6. The automatic lock slider of claim 1 in which the front arm comprises a rigid elongated cap having a front wall and side walls, and in which the said rear arm is resilient and is united to one of said side walls.

'7. The automatic lock slider of claim 2 in which the front arm comprises a rigid elongated cap having a front wall and rearwardly turned side walls, in Which the said rear arm is resilient and is integral with one of said side walls and said locking detent is located on said resilient arm, and a second locking detent on said other side wall also projecting into the slider channel.

8. The automatic lock slider of claim 5 in which the rigid front arm comprises an elongated cap having a front Wall and rearwardly turned side Walls, a pull device pendent from said side walls, in which the said resilient rear arm is integral with one of said side Walls and said locking detent is located on said resilient arm, and a second locking detent on said other side wall also projecting through its front wing orifice into the slider channel.

9. An automatic lock slider for a slide fastener comprising, a slider body having front and rear wings spaced to provide a slider channel for the slide fastener stringers, and a locking member mounted on said front wing, said locking member comprising a front arm and a rear arm united together at their bottom ends and free at their top ends, said arms being movable resiliently one with respect to the other, the free top end of the front arm and the free to end of the rear arm straddling a wall of the said front slider wing and bearing against opposite sides of said wall, the thus straddled w-all forming a fulcrum seat for the front arm and a bearing for the rear arm, said locking member having a detent adjacent its bottom end projecting into the slider channel.

10. An automatic lock slider for a slide fastener comprising, a slider body having front and rear wings spaced to provide a slider channel for the slide fastener stringers, the front wing being provided with an orifice, and a locking member mounted on said front wing, said locking member comprising a front arm and a rear arm united together at their bottom ends and free at their top ends, said arms being movable resiliently one with respect to the other, the free top end of the front arm and the free top end of the rear arm straddling a Wall of the said front wing and bearing against opposite sides of said wall, the thus straddled Wall forming a fulcrum seat for the front arm and a bearing for the rear arm, the rear arm extending into said front wing orifice, said locking member having a detent adjacent its bottom end projecting through the front wing orifice into the slider channel.

11. An automatic lock slider for a slide fastener comprising, a slider body having front and rear wings spaced to provide a slider channel for the slide fastener stringers, a unitary locking member mounted on said front wing, said unitary locking member comprising a rigid front arm and an integral resilient rear arm united at their bottom ends and free at their top ends, the free top end of the rigid arm and the free top end of the 1:5

resilient arm straddling a wall of the said front Wing and bearing against opposite sides of said wall, the thus straddled wall forming a fulcrum seat for the front arm and a bearing for the rear arm, said locking member having a detent adjacent its bottom end projecting into the slider channel, the fulcrum and bearing points for both arms being disposed to normally urge the locking member to locking position, and a pull device pendant from said locking member to move the same to unlocking position.

12. The automatic lockslider of claim 9 in which the front arm comprises a rigid elongated cap having a front wall and rearwardly turned side Walls, a pull device endent from said cap, {Q

the said rear arm being resilient and united to one of said side Walls.

13. The automatic lock slider of claim 10 in which the front arm comprises a rigid elongated cap having a front wall and rearwardly turned side walls, in which the said rear arm is resilient and is united to one of said side walls and the locking detent is located on said resilient arm, and a second locking detent on said other side wall also projecting through the front wing orifice into the slider channel.

14. The automatic lock slider of claim 11 in which the rigid front arm comprises an elongated cap having a front wall and rearwardly turned side walls, in which the said resilient rear arm is integral with one of said side walls and the locking detent is locatedon said resilient arm, a second locking detent on said other side wall also projecting through the front wing orifice into the slider channel.

15. The automatic lock slider of claim 11 in which the rigid front arm comprises an elongated cap having a front wal1 and rearwardly turned side walls, in whichthe said resilient rear arm is integral with one of said sidewalls and the locking detent is located on said resilient arm, a second locking detent on said other side wall also projecting through the front wing orifice into the slider channel and a stop member in said other side wall also straddling the said fulcrum seat.

16. An automatic lock slider for a slide fastener comprising, a slider body having front and rear wings spaced to provide a slider channel for theslide fastener stringers, and a locking member mounted on said front wing, said locking member comprising a front arm and a rear arm connected together at their bottom ends and free at their other ends, said locking member having a detent adjacent its bottom end projecting into the slider channel, a rearwardly projectin finger inset from the free end of the front arm, the free end of the front arm and the free end of the rear arm straddling a wall of the said front wing and said finger engaging said wall, the thus straddled wall forming a double fulcrum seat, one for the free end of said front arm operative when the locking member is moved to unlocking position, the other for said finger operative when the locking member is forced by the stringers to the locking position.

17. An automatic lock slider for a slide fastener comprising, a slider body having front and rear Wings spaced to provide a slider channel for the slide fastener stringers, and a locking mem ber mounted on said front wing, said locking member comprising a front arm fulcrumed on said front wing and provided With a detent adjacent its bottom end projecting into the slider channel, a spring acting on said arm to move the same to locking position, a rearwardly projecting finger inset from the top end of said front arm, the top end of the front arm and said finger engaging a wall of said front wing, said wall form-= ing a double fulcrum seat, one for the top end of said front arm operative when the locking mem-- ber is moved to unlocking position, the other for said finger operative when the locking member is forced by the stringers to the locking position.

18; An automatic lock slider for a slide fastener comprising, a slider body having front and rear wings spaced to provide a slider channel for the slide fastener stringers, and a locking member mounted on said front wing, said locking member comprising a front arm and a rear arm integrally united at their bottom ends and free at their top ends, said locking member having a detent adjacent its bottom end projecting into the slider channel, a rearwardly projecting finger inset from the free end of the front arm, a stop element on said finger, the free end of the front arm and the free end of the rear arm straddling a wall of the said front wing and said finger engaging said wall, the thus straddled wall forming a double fulcrum seat, one for the free end of said front arm operative when the lockin member is moved to unlocking position, the other for said finger operative when the locking member is forced by the stringers to the locking position, the said stop element being adapted to engage said wall to limit outward movement of the looking member.

FREDERICK ULRICH.

CLAUDE DISINGER.

nnrnnnnons orrnn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,215,745 Sundback Sept. 24, 1940 2,322,826 Carlile June 29, 1943 2,360,437 Mikulas et a1. Oct. 1'7, 1944 FOREIGN PATENTS Number Country Date 400,782 Great Britain Nov. 2, 1933 648,831 Germany Aug. 11, 1937