CA1280877C

CA1280877C - Method and apparatus for making a pull cord extension assembly

Info

Publication number: CA1280877C
Application number: CA000524037A
Authority: CA
Inventors: C. James Mack; James Michael Murphy; Phillip Dewitt Baker; James Denny Norris
Original assignee: Leviton Manufacturing Co Inc
Current assignee: Leviton Manufacturing Co Inc
Priority date: 1986-06-23
Filing date: 1986-12-01
Publication date: 1991-03-05
Anticipated expiration: 2008-03-05
Also published as: GB8707386D0; GB2192362A; KR910001567B1; KR880000206A; GB2192362B

Abstract

ABSTRACT OF THE DISCLOSURE

METHOD AND APPARATUS FOR MAKING A PULL CORD EXTENSION ASSEMBLY

A connector for bead-chain having: a chain entry and hold area is molded joined together with a tassle, on a portion of a continuous flexible line, positioned so that the line is captured in each while in the connector is not in interference with the chain entry and hold area. The line is moved a predetermined distance and the operation is repeated on another portion of the line with the second molding oriented so that the second connector molded is attached by the line to the first tassle molded. The operations repeat whereby the completed pull cord assemblies may be stored end to end on a pick up spool.

Description

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METHOD AND AppARArus FOR MARING
A PULL CORD EXTEMSION ASSEMBLY

Background of the Invention:

: Field of the Invention:

The present invention relates to a method of making an assembly. More particularly, the present invention is directed towards the ~ethod of making an extension assembly including a ~: 5~ conneceor for bead-cbain, a tassle and b thin flexible line joinlng the connecto tv the tassle.
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~: : : Background of the Invention:

Pull cord extension assembl~ies, generally used to operate . switches in pull-chain lamps and t~hè like, are attached to the :10 switches' bead-chains by their connectors and are pulled by the tassle to operate~the ~wltches,:~

Methods for their manufacture, according to the present art require individual attention to each assembly. ~or the connector, one end of the f1exib1e line is installed within and a knot i~ tied which mUct be kept to what mby be considered :106e tolerance~ in view of the material in which it is tied.

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~ ' . : .`, `: ' ' If the knot or th~ rem~ining line end ~s too large, an interference will develop for later in~tall~tion of the connector to the bead-chain For the tassle, the other end of the line 16 in~talled and a knot must be tied that i6 not so 5 large that it protrudes from the interior of the tassle or so small that the line can be pulled ~ack ~ut of the tassle when the tassle is pulled ~o operate ~ switch.

In accordance with the invent~on, ~ connector having a chain entry and hold area and a tassle are molded on a portion of the line, joined together and positioned so that the line is captured in each, while in the connector is not in interference with the chain entry and hold area. The line is moved a predetermined distance and the operation is repeated on another portion with the second molding oriented so that the ~econd connector molded is attached by the line to the first tassle : molded. The operations repeat on a continuous line whereby the pull cord asse~blies may be stored end to end on a pick up ~pool.
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~ach assembly is attended to ~eparately and the methods presently used do not lend themselves to economical automated manufacture.

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, -" 1280~37~7 Summary of the Invention:

It is one object of the invention to provide a method of making a pull chain assembly which provides continuous, unbroken manufacture, rather than constructing each assembly on an individual basis.

It is another object of the invent~on to provide a method of molding the sssembly.

It is another object of the invention to provide simultaneous automatic~olding of large numbers of assemblies.

~ ~ 10 Yet an~other object~ of the inventlon is to provide a connector with permits attachment of the chain without interference from a ; knot.

And another object of the invention is to provide an apparatus for manufacturing the pull~chain assemblies according to the method of the invention.

Other objects and advanta~es of the ~invention will be ~ ~ ~pparent to one killed in the art~
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~L280~37~7 _ ief Description of the Drawin~s:

Figs. 1 and 3 are axial sectional views of a presently used connec~or and tassel with partially attached line~.

Figs. 2 and 4 are perspective views of a connector and a tassle made by the present invention.

Fig. 5 is ~ perspective view of the connector of Fig~ 1.

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Fig. 6 i~s a front elevational~view of an apparatus for carrying out the method of the invention.

Fig 7. is a plane view of an apparatus for carrying out the method for ~imultaneous manufacture of six assemblies.

Fig. 8 is a front elevational axial section view of a mold cavity block for ~imultaneous manufacture of six assemblies.

Fig. 9 i~ partial ~ectional view of an apparatus for carrying out the ~ethod of the invention.

; Refer~ing now to the drawin~s, comparison may be made between: a) present type connector 1 Figs. 1 and 5 for , : -bead-chain 2 and flexible line ~uch a~ a ~tring 3, and tassel 13 Fig. 3 for flexible line ~uch as a string 3 and; b) connector 4 .~

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Fig. 2 for bead-chain 2 and line 3, and tassel ll for line 3, which ~ay be made by the present invention.

Installation of line 3 in co~nector l req~ires several operations which are: positioning the line through hole 5, through hollow connector shell 6, through shell opening 7, tying retaining knot 8 in the line's connector end 9 and then pulling the line back through hole 5 until the knot i8 ~ituated within the connector'~ shell. The distal end lO of line 3 continues tnot shown) on to connect to tassel 33 shown in ~ig. 3 where it ; 10 is Installed by p~sitioning it through hole 12, through ~hell ; 13, through opening 14, tying retaining knot 15, then drawing the line ~ack through hole 12 until knot 15 is situated within the tassel's shell.

Connector 4 ~ig, 2 and tassel 1l Fig.4, on the other hand ~; ~15 are molded by in]ection molding or other ~ethod with the line on a continuous bas16 by the~present invention as will be explained with reference to the remaining drawings, thus eliminating the above slow and costly operations.

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~Connectors l;and 4 of Figs. l and 2 are used to attach their :
20 re~pective lines 3, 3 and tassels 33, 1l of Figs. ~ and 4 to bead-chain 2. The distal end tnot shown) of bead-chain 2 is normally attached to a ~pul1 chain switch~ mechanism of the type often included in pull chain light fixture- socket~.

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The bead-chain is attached to either type connector in 8 similar manner. In presently used connectors Figs. 1 and 5, a bead 17 of chain 2 i5 in~erted into opening 7 and positioned ~o that its link 18 with the remainder of the chain is slidably 5 located in slot 19. The chain ic then pulled so that the lini:
slides back to opening 16, thereby capturing the inserted bead and with it~ the chain.

Difficulty often arises in th;s connector, between attachment of tbe line and the chain. The knot must be ~ade large enough to prevent slipping out ~hrough opening 5, yet it must be small enough, and line end 9 must be cut short enough ~ ~ without affecting knot integrity, to provide clearance for bead s; entry in:to opening 7. In turn, if the chain is attached first, ~ the bead extends over part of opening 7, complicating attaching .i ~
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`,~; ~ ' In the connector made by the present invention, Pig. 2 the chain~ is installed by inserting a bead 17 of chain 2 into opening 20 with link 18 slldably located in ~lot 21. The chain i8 then pulled &0 ~hat link 18 m~ves to opening 22, thereby : ~ 20 oapturing the chain by the inserted bead. There is no interference between line 3 and the chain as described earlier `;~ because,~ during operation of the Invention, it was molded both .;~ with its end displaced from the connector's centerline and excluded~from the chain entry and holding areas comprising ~ocations 20, 21, and 22.

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In the tassel 11, Pig. 4 made by the present invention, line 3 i8 automatically tnolded in and no further assembly is necessary.

According to the method of the in~ention ill~strated b~ Fig.
6, there is provided line 3, loaded on supply spool 23 ~ounted for rotation on frame 24. The line is intermittently drawn s~raight to pick up spool 25, mounted on base 24 at a suitable d;stance from spool 23~ Injection mold split cavity block 26 and mating head 27 are mounted for operation between the two spools so that may close on the line without deflection which would cause the line to be drawn foward or back from the spools.

~, In operation, the mold is closed on line 3, capturing a portion of it in mold cavity 28. Plastic is injected into the cavity by way of channel 29 to sprue~channel 30 in a 1S conventional manner for injection molding that is known to the art. After a molding cycle is completed the molded is opened and the line is advanced tQward the take up spool for a distance equal to the line length desired on the finished Pull Cord ~xtension Assembly. ~ach molding cycle re~ults in a connec~or joined by gate 31 and sprue to a tassel. The cycle is repeated with each line advance so that continuous sets of pull cord extention assemblies;are ~ade, attached to each other by the gstes and ~prues. The gates and sprues may be formed so that the ~prue ~erves to feed plastic to the gate and plays little ' , ' ~
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~L280~3~7 part in direct joining between the connector and tas~el. For minimum leakage during molding, it i8 preferred that the line is routed through the cavity by way of the two gate channels. It mav also run across the sprue channel as well, if the spring inte~ceptE it.

Figs. 7 and 8 illustrate simultaneous forming of assemblies on a si~-bank machine frame 34. Mold cavity block 35 and mating head 3~ operate to simultaneously mold connectors 4, tassels 11 ~ith the sprue and their attachment gates which incorporate the line within them. Connectors' 4 cavities are positioned with their tips concentric with line 3 and their axis slightly angled from that of the line line so that the line is captured in plastic~ outside of chain entry and hold areas comprising opening 20, slot 21 and opening 22.

After each molding cycle, pick up spools 25, mounted on drive shaft 37, draw the molded strip of parts from the open mold. Supply spools 23 mounted on shaft 38 ~upply the contlnuous lines. ~eating elements 39 are provided to accommodate the molten-plastic supply channels 40 as shown in Fig. 8.

It i~ within the cont-emplation of the invention that ~pacing/cutting station ~1 $s provided for ~ectioning the sprue 80 that each line of pull cord extension assemblies may be wound ... .
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`'` :,' for storage on the indi~idual take up ~pools on shaft 37. It also serves to stop the lines for the next cycle ~fter the molded strip has been moved a suitable distance from the mold cavity. Foward and reverse clutch or other tension means may be used to take ~p slack, : It is also within the contemp1ation of the invention that molds may be sequenced along lengths of the line for ; simultaneous molding, wherein the line is moved a distance : sufficient to clear the molded part~ from the cavities and provide proper~line lengths ~or the next molding as discussed ~; supra.:

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In the embodiment shown in Figs. 8 and 9, heating elements facilitate bringing molten plastic directly to the gate channels, eliminating the sprue. :Plastic:injection 6upply 42 ~: 15 delivers molten plastic shots by way of heated channel 29 to :
old cavity 28 to for~ connector 4, gate 31 and tassel 11 as one unit on each line which has its own supply spool 23, ~pring ; loaded tensioner assembly 43 for minimi~zing slack in the line, supply~guide r~oller 44 and pick-up guide roller 45 to keep the line straight, and pick up spool 25. Clamping ~tation 46 may be .~:
used to control l~ine travel~:between each cycle to overcome : pick-up 6pool diameter change a6 it collects the pu11 cord extension assemblies for storage~: `
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When it i6 desired that the pull cord extension assemblies be separated for packaging or u6e, they ~ay be cut; t~ssel 11 Fig. 4 at line end 37 and connector 4 ~ig. 2 at line end 3B.

In vie~ of the preceeding description, i~ is seen that the present invention provides a method for making a pull cord extension assembly which reduces time and cost in attaching the line between connector and tassel including a knot tying operation, provides si~ultaneous automatic ~olding of large numbers of assemblies, and provides a connector which permit~
attachment of the chain without interference from a line knot.

Although va~ious embodiments of the lnvention have been described and shown, it is obvious that varioas modifications an~ changes can be made without departing from the ~cope of the invention which shall be limited by only the follawing claims.

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Claims

1. A method of making a pull cord extension assembly including;
a) a connector for bead-chain, having a chain entry and hold area, b) a tassle, and c) a thin flexible line joining the connector to the tassle, wherein the method comprises:

taking a length of said line and, A- molding a first connector joined with a first tassle and capturing a portion of line: within the connector for passing through but not in interference with the chain entry and hold area, and capturing an additional sequential portion of line within the tassle for passing through it and, B- molding a second connector joined with a second tassle, at another location on the same line, and capturing a portion of said line within the connector for passing through but not in interference with the chain entry and hold area, and capturing an additional sequential portion of line within the tassle for passing through it, the second connector and second tassle molding is made so that the second connector is attached by the line to said first tassle, thereby forming said pull cord extension assembly between the two molding locations on the line.

2. The method recited in claim 1 wherein each connector and tassel joining is made with a gate which is molded with them and, line which runs between the sequential portions captured in each is molded into said gate.

3. The method recited in claim 1 in which the molding steps A and B are carried out sequentially.

4. The method recited in claim 3 in which the sequential molding steps are carried out by intermittently moving the line through a molding machine, pausing for each molding step.

5. The method recited in claim 4 in which the line is moved a measured distance after a molding step and then is restrained from movement for the next molding step.

6. The method recited in claim 5 in which a plurality of assemblies are made simultaneously by passing a plurality of lines through the molding machine.

7. A method of making a series of pull cord extension assemblies, each assembly including; a) a connector for bead-chain, having a chain entry and hold area, b) a tassle, and c) a thin flexible line joining the connector to the tassle, wherein the method comprises:

providing line from a supply spool, applying tensioning force to minimize slack and guiding it for proper alignment through a molding die, injecting heated molten plastic material into the die and, A- molding a first connector joined with a first tassle and capturing 2 portion of line within the connector for passing through but not in interference with the chain entry and hold area, and capturing an additional sequential portion of line within the tassle for passing through it and, B- moving the line so that a new location on the line is positioned in the mold, C- molding a second connector joined with a second tassle, at the new location on the same line, and capturing a portion of said line within the connector for passing through but not in interference with the chain entry and hold area, and capturing an additional sequential portion of line within the tassle for passing through it, the second connector and second tassle molding is made so that the second connector is attached by the line to said first tassle, repeat steps A through C, injecting molten plastic material into the die for each molding step, collect the line with molded parts on a pick up spool.

8. An apparatus for making a series of pull cord extension assemblies, each assembly including; a) a connector for bead-chain, having a chain entry and hold area, b) a tassle, and c) a thin flexible line joining the connector to the tassle, said apparatus comprising:

a supply spool, a first guide roller, a second guide roller and a pick up spool, a thin flexible line provided by the supply spool, said line is engaged by the first and second guide rollers and the pick up spool for receiving the line, tensioner means engaging the line for reduction of slack in the line, means for molding including a molding cavity, located between the first and second guide roller for enclosing a portion of the line in the cavity, said cavity is contoured for molding a connector joined with a tassle and oriented so that the enclosed line is molded into the connector for passing through but not in interference with the chain entry and hold area, and also so that the enclosed line is molded into the tassle for passing through it, means for moving the line after molding so that a new portion of the line is enclosed in the cavity for molding.

9. The apparatus recited in claim 8 wherein the molding means comprises an injection molding machine for plastics and further comprising:

heating elements arranged for heating the plastic as it is delivered to the cavity.

10. The apparatus as recited in claim 9 further comprising:

means for clamping the line for controlling the distance the line moves after molding.