US2824316A - Means permitting limited retrograde movement of strip stock on retraction of feed means - Google Patents

Description

Feb. 25, 1958 c. P. MICHLEIN 2,324,316

MEANS PERMITTING LIMITED RETROGRADE, MOVEMENT OF STRIP STOCK ON RETRACTION OF FEED MEANS 2 Sheets-Sheet 1 Filed Sept. 8, 1954 INVENTORA Carl PMicizZem BY ATTORNEYS Feb. 25, 1958 c. P. MICHLEIN 2,824,316 MEANS PERMITTING LIMITED RETROGRADE, MOVEMENT OF STRIP STOCK ON RETRACTION OF FEED MEANS 2 Sheets-Sheet 2 Filed Sept. 8, 1954 m m m w MA P MW 6 United States Patent MEANS PERMITTING LIIVIITED RETROGRADE MOVEMENT OF STRIP STOCK ON RETRAC- TION OF FEED MEANS Carl P. Miclilein, Shelton, Conn., assignor to The Shelton Tack Company, Shelton, Conn., a corporation of Connecticut Application September 8, 1954, Serial No. 454,813

7 6 Claims. (Cl. 10-178) I This invention relates to apparatus for longitudinally advancing or feeding flat bar or strip stock, and more particularly to. strip-feeding apparatus used in conjunction with a machine which is adapted to fabricate articles from the strip..

The invention is illustrated and described in connection with the making of carpet tacks; however, it should be understood that such disclosure is for illustrative purposes and that the invention is not limited to the specific machine shown since it has utility generally in the field of strip feeding.

Heretofore, inthe manufacture of carpet tacks by automatic machinery, the strip stock from which blanks or slugs were cut was not taken from a continuous supply or coil but instead was fed to the machine in the form of long, straight strips of determinate length.

This procedure necessitated considerable attention being given by the operator to each machine, since it was necessary at brief intervals to replenish the supply to the machines with new strips of stock.

This disadvantage is obviated by the present invention, and an object of the invention is to provide an improved and simplified means for feeding strip stock to a tack machine from a continuous coil which contains a very.

great length of the stock. 7

Another object of the invention is to provide an improved apparatus for intermittently feeding strip from a continuous coil or supply of the stock.

A still further object of the invention is to provide an improved'strip-feeding apparatus in accordance with the foregoing, which is simple in construction with relatively few parts, is small and compact, reliable and foolproof in its operation and economical to produce.

A feature of the invention resides in the provision of an improved strip-feeding apparatus as above set forth, wherein the operating parts and components are readily accessible for inspection or servicing.

Other features and advantages will hereinafter appear.

In the accompanying drawings:

Figure 1 is a side elevational view of a tack machine and improved strip feed made in accordance with the invention.

' Fig. 2 is a perspective view of a continuous coil of strip stock, carried by a supporting means which enables the strip to be fed continuously from the coil.

Fig. 3 is a transverse vertical section taken on line 3--3 of Fig. 1.

Fig. 4 is atransverse vertical section taken on line 4-4 of Fig. 1.

Fig. 5 is an axial sectional view of the feed head of the apparatus.

Fig. 6 is a left end view of the feed head shown in Fig. 5.

Fig. 7 is a transverse sectional view taken on line .7-7 of Fig. 5.

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Fig. 9 is a perspective view of a sliding collar employed in the construction of Fig. 5.

Fig. 10 is a perspective view of a guide and support arm included in the structure of Fig. 5.

Fig. 11 is a view like Fig. 5 but showing a modification of the invention.

Referring to Fig. 1, a tack machine is shown comprising a base 20 supporting a machine frame 21 which has uprights 22 provided with bearings 23, the latter carrying a main crank or carn shaft 24. The shaft 24 operates a ram 25 having shearing tools or bits 26 cooperable with a bed knife 27 for cutting slugs from strip stock fed to the machine. Cooperable with the shearing tools 26 is a clearer bar 28 which holds the cutoff slugs against one of the tools 26 as the latter descend past the bed knife 27.

Adjacent the shearing tools 26 is a guide or stop 29 adapted to be engaged by the advancing end of the strip stock 30 which is fed to the machine.

In accordance with the present invention a novel and improved apparatus is provided in conjunction with the tack machine by which continuous strip stock may be fed thereto from a continuous coil or supply. Referring to Fig. 2, the strip 30 is shown as being supplied in a coil 31 which is mounted on a holder 32 adapted to feed the strip from the coil. The improved strip-feeding apparatus of my invention is arranged to receive the continuous strip 30 from the coil 31 and to intermittently feed the strip into the tack machine.

Referring again to Fig. 1 the improved feeding apparatus comprises an elongate guide barrel 33 through which the strip 30 may pass, with a certain amount of clearance. The guide barrel 33 carries a semi-spherical knuckle or bearing member 34 which is held in a stationary socket 35 mounted on a post 36, the latter in turn being carried by an arm 37 secured to the base 20 of the machine.

The arm 37 also carries a depending bracket 38 mounting a shaft 39 which has oppositely-extended arms 40 connected by flexible straps 41 to the barrel 33. The straps 41 wrap around the barrel 33 in opposite directions, whereby oscillation of the shaft 39 will cause corresponding oscillation of the barrel 33. One of thearms 40 has connected to it a depending drive arm 42 actuated by a link 43 which is reciprocated by suitable mechanism (not shown) in the tack machine.

The guide barrel 33 slidably carries a collar bearing 44 held by springs 45 in a guide fork 46 mounted on the supporting arm 37 of the apparatus.

Referring to Fig. 5, the guide barrel 33 at its lower end has disposed within it a bushing 47 carrying a guide member 48 in the form of a disc having an elongate central opening or slot 49 through which the strip 30 passes.

Referring to Figs. 7 and 8, the lower end portion of the guide barrel 33 has secured to its side a bar 50 constituting a longitudinally-extending rib, and attached to the rib 5.0 is a guide and support arm 51, Figs. 5, 7 and 10, having a laterally-extended extremity 52 provided with a slit 53 through which the strip 30 extends.

Slidably mounted on the lower end of the guide barrel 33 is a collar 54 having a longitudinal slot 55 in it, said slot providing clearance for the rib 50. The collar 54 carries a gripper means comprising a strip supporting member '56 and a bearing member 57, the latter pivotally carrying an angularly disposed clamping arm 58 mounted by a screw 59 and urged by a helical compression spring 60 into engagement with the strip 30, saidstrip being thereby maintained in engagement with a surface 61 of the support member 56. The gripper means thus provided has a unidirectional action, gripping the strip 30 and feeding the strip from right-to-left in response to like movement of the collar 54, and enabling the collar and 3 gripper to move from left-to-right without movement of the strip 30.

The collar 54 is connected by links 62 to a second collar 63 slidably carried on the guide barrel 33, thecollar 63 having an annular groove 64 accommodating pins 65, Fig. 4, carried by arms 66 secured to a shaft 67 which is turnable in a bearing bracket 68 carried by the fork member 46. The shaft 67. has a depending operating arm 69 connected through a yieldable driving connection 70 to a link 71 which is reciprocated by a bell crank 72. actuated by a cam shoe 73 on the shaft 24 of the machine. Adjustment of the stroke of the bell crank 72 is effected by an adjusting screw 74 carried by the machine. By the above construction it will be seen that reciprocation of the gripper members 56 and 57 is effected in response to turning of the shaft 24.

Referring again to Fig. 1, the guide and support arm 51 is so arranged and organized as to rest on the bed knife 27, thereby supporting the lower portion of the guide barrel 33 and the gripper means carried thereby during the operation of the feeding apparatus.

Operation of the apparatus as described above, is as follows:

Turning of the shaft 24 will reciprocate the ram 25 of the tack machine, lowering and raising the shearing tools 26 and enabling them to shear off end portions of the strip stock in conjunction with the bed knife 27. The stock 30 is sheared off at an angle which differs slightly from 90 degrees relative to the length of the strip.

Turning of the shaft 24 oscillates the bell crank 72 and reciprocates the gripper members 56, 57 and the collars 54 and 63. This will cause intermittent feeding or advancing of the strip 30 toward the tack machine. An overfeed is provided by the cam 73, and as the foremost end of the strip 30 engages the guide 29 it will be halted, the rest of the feeding movement of the bell crank and link 71 being absorbed by the yieldable spring connection 70.

At the same time that the gripper members are reciprocating, the guide barrel 33 is caused to turn or oscillate through an arc of 180 degrees by virtue of reciprocation of the drive link 43. This will cause the opposite sides of the strip stock 30 to be alternately presented to the shearing tools 26, and by such arrangement the cutoff slugs will be made to have a wedge shape which is of importance in the formation of carpet tacks and the like.

Oscillation of the guide barrel 33 and gripper means about the axis of the barrel will cause a twisting of the strip 30 within the barrel. With the supply coil 31 placed in a horizontal plane as shown in Fig. 2, the strip 30 will extend in a vertical plane and be twisted in opposite directions through arcs of 90 degrees, thereby being fed substantially horizontally to the shearing tools 26.

During the oscillation of the gripper means 56, 57 about the axis of the guide barrel 33, the support arm 51 will also oscillatebut will remain in contact with the bed knife 27, providing a support for the lower portion of the guide barrel and for the gripper means, and insuring that the strip 30 will be positioned against the top surface of the bed knife 27.

I have found that the twisting of the strip 30 within the guide barrel 33 provides a desirable, yieldable gripping action in conjunction with the guide 48. By properly proportioning the diameter of the guide barrel 33 with re spect to the width of the strip 30, the twisting force existing at the guide 48 will permit a slight retrograde movement of the strip 30 but will prevent any appreciable retrograde movement from occurring. This is highly desirable, since it provides a clearance between the foremost end of the strip 30 and the shearing tools 26 and guide 29 during the return stroke of the tools, yet the strip 30 is held sufficiently to enable the gripper members 56 and 57 to retract without pulling back the strip. Thus the clampmg arm 58 is enabled to take a new bite into the strip.

4 The guide 48 thus constitutes in effect a back check, in conjunction with the twisting action of the strip 30, and this is an important feature of the present invention.

A modification of the invention is shown in Fig. 11, and components in this figure which are similar to those already described above have been given like characters. The ditference between the construction of Fig. 5 and Fig. 11 resides in the strip guide and back-check means. In Fig. 5, the guide and back check comprises a single member 48 having an elongate slot through which the strip 30 passes. In Fig. 11 a spring-charged back check 75 is provided, secured to the bushing 47, the back check 75 comprising a support member 76, a bearing member 77, a pivoted clamp arm 78 and a retainer screw 79, the latter carrying a compression spring 80 normally urging the clamping arm 78 clockwise or to the right as viewed in Fig. 11.

The clamping arm 78 is arranged to enable a slight amount of retrograde movement of the strip 30 to be had in response to left-to-right movement of the gripper members 56 and 57. This provides the clearance for the shearing tools 26. The back check 75 prevents appreciable retrograde movement of the strip 30, however, thereby enabling the gripper means 56, 57 to get a new bite each time it is reciprocated, thus effecting a reliable intermittent advance or feed of the strip 30 without binding of the shearing tools.

Variations and modifications may be made within the scope of the claims and portions of the improvements may be used without others.

I claim:

1. Means for feeding a continuous supply of flat strip from a reel comprising a guide having an opening through which the strip can pass and advance; means mounting the guide for turning movement about said opening, said guide comprising support means positioned on one side of the strip and a bearing means diametrically opposite the support to define therebetween a slot slidingly engageable with opposite sides of the strip and imparting to said strip a twisting movement in opposite directions about its length; a unidirectional-acting gripper means cooperating with said guide and engageable with said strip for gripping the same, said gripper means being axially movable relative to said guide opening to impart longitudinal advancing movement to the strip and being keyed to the guide against relative turning; said guide being formed to provide a barrel portion on the side of the slot opposite the gripper means and having a diameter determinately larger than the width of the strip; and baclccheck means including a pivotally mounted clamp arm opposite and extending towards the support means; and adjustable spring means biasing the arm towards the barrel portion with sufficient tension to enable a slight retrograde movement of the strip prior to locking of the strip by the clamp arm, whereby the strip when being twisted from one side to the other is permitted to buckle within the barrel a determinate amount to cause a slight retrograde movement thereof which provides a clearance for the foremost end of the strip and the back-check means enables the movement but prevents appreciable retrograde movement.

2. The invention as defined in claim 1 in which there is a second guide for the strip, fixedly secured to the firstmentioned guide and engaging the strip at a point remote from the first-mentioned guide; and means providing a supporting surface, said second guide resting on said surface and supporting the first-mentioned guide and gripper means thereby.

3. The invention as definedin claim 1 in which the gripper means comprises a pair of arms extending beyond said guide and spaced from said guide opening, one of said arms forming a support, and a pivoted angularlydisposed pawl arm connected to said other arm biased toward said support, said pawl arm being adapted to clamp the strip against the support.

4. The combination of a supply coil of flat strip stock; means for supporting said coil, to enable the strip to be fed therefrom; a guide including a support means positioned on one side of the strip and bearing means diametrically opposite the support to define therebetween a narrow slot through which the strip extends, said slot closely, slidably confining the strip; means mounting the guide for turning movement about said slot, said guide imparting turning movement to the strip about its length when the guide is turned; a unidirectional-acting gripper means carried by the guide and gripping said strip, said gripper means being movable on said guide axially of the slot therein and imparting longitudinal advancing movement to the strip when so moved, and said gripper means being keyed to the guide against relative turning; a guide barrel rigidly connected to the guide and enclosing and supporting the strip in a zone between the guide and supply coil, said barrel closely confining the strip and being determinately larger than the strip to permit a controlled amount of buckling of the strip therein; and back-check means including a pivotally mounted clamp arm opposite and extending towards the support means; and adjustable spring means biasing the arm towards the barrel portion with sufiicient tension to enable a slight retrograde movement of the strip prior to locking the strip, whereby the strip when being turned from one side to the other is permitted to buckle within the barrel a determinate amount to cause a slight retrograde movement thereof which provides a clearance for the foremost end of the strip and the back-check means enables the slight movement but prevents appreciable retrograde movement.

5. Means for feeding a continuous supply of flat strip comprising a guide having an opening through which the strip can pass and advance; means mounting the guide for turning movement about said opening, said guide having portions slidingly engageable with opposite sides of the strip and imparting to said strip a twisting movement in opposite directions about its length; a unidirectional-acting gripper means cooperating with said guide and engageable with said strip for gripping the same, said gripper means being axially movable relative to said guide opening to impart longitudinal advancing movement to the strip and being keyed to the guide against relative turning; said portions of the guide providing a desirable, yielding, gripping action during twisting of the strip whereby the twisting force existing at the guide allows a slight retrograde movement of the strip to provide a clearance for the foremost end of the strip, yet holding the strip sutficiently tight to enable the gripper means to retract without pulling back on the strip, thus constituting an effective back check; in which the gripper means has a collar extending around the guide and having a longitudinal slot in it; and in which the guide has a longitudinal rib occupying the said slot, the rib and slot constituting keying means between the guide and gripper means.

6. The invention as defined in claim 5 in which there is a second guide for the strip, fixedly secured to the firstmentioned guide and engaging the strip at a point remote from the first-mentioned guide, said second guide being attached to the said longitudinal rib.

References Cited in the file of this patent UNITED STATES PATENTS

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