US3117344A

US3117344A - Mold for making plastic coil with straight leads

Info

Publication number: US3117344A
Application number: US159519A
Authority: US
Inventors: Carl A Redmer
Original assignee: Carmer Ind Inc
Current assignee: Carmer Ind Inc
Priority date: 1961-12-15
Filing date: 1961-12-15
Publication date: 1964-01-14
Anticipated expiration: 1981-01-14

Description

MOLD FOR MAKING PLASTIC con. WITH STRAIGHT LEADS C. A. REDMER Jan. 14, 1964 2 Shqets-Sheet 1 Filed Dec.

INVENTOR. CARL A. REDMER ATTORNEY MOLD FOR MAKING PLASTIC COIL WITH STRAIGHT LEADS Jan. 14, 1964 c. A. REDMER Filed Dec.

2 Sheets-Sheet 2 FIG. 4

FIG. 3

FIG. 5

INVENTOR.

CARL A. REDMER. BY

ATTORNEY United States Patent 3,117,344 MULD FOR lvlAKlNG PLASTIC COIL WITH STRAIGHT LEADS Carl A. Redmer, Cranford, N.J., assignor to Carmer gndustries, Inc., Parsippany, NJ, a corporation of New ersey Filed Dec. 15, HQ, Ser. No. 159,519 3 Claims. (Cl. 18-19) This invention relates to a mold for producing a siphon attachable to a tapper valve of a keg, such as an aluminum beer keg, and to the process of making same. More specifically it relates to a method for producing a coiled plastic siphon having straight extending ends, and to a mold for producing said siphon.

In recent years, there has been a demand for a sanitary exible siphon capable of attachment to the tapper valve of an aluminum beer keg, for example, which would retain its original shape after numerous sterilizations at scalding temperatures. Such a siphon has been sought by makers of kegs for several years, and many plastic processors and other technicians have tried in vain to effect a satisfactory solution to the problem.

Among the requirements for such a siphon are the following: In the first place, it must be a small flexible tube of exact length, e.g., 25 inches, plus 0.25 inch minus zero inch, for a specific keg application, and such length must be compacted into a length of about 6% inches. The reason for the overall tube length limitation is that it must draw 13 ozs. of beer in seconds, without exces sive foam, and research has determined that the aforesaid specified length will accomplish this. However, since the distance from the tap valve connection to the center of the barrel bottom is about 6 /4 inches, this 25" length must be compacted (e.g., by coiling) to the 6 /4" distance.

The next requirement is that the tube, when free, at all times maintain each end (about 2 /8") extending from the coil straight horizontally and in alignment in spite of repeated sterilization heats of 210 F., followed 10 seconds later with passage therethrough of beer at 32 F. When in use, one straight end of the tube is attached to the tapping valve connection, while the other (extending) end must lie fiat on the keg bottom to insure drainage of the entire contents of the keg.

Another requirement is that the coil be essentially round (i.e., unilattened) in order to effect the required passage of beer in the specified time, and the coils must be separated (about from each other, since the Government considers closed coils as unsanitary because they tend to breed bacteria. Furthermore, the outside diameter of the coil must not exceed 1.000 inch diameter- *0.060, since it must be inserted into and removed from the keg tapping hole.

A still further requirement is that the plastic used for the tubing be of natural color, odorless, tasteless, and must hold its shape at 200 F. for 2 minutes and at 32 F. for storage. The only plastic material approved by the Government for such application is a nylon (polyamide) plastic sold commercially as Zytel 31, or its equivalent. According to its specifications, this material is recommended for temperatures of 270-300 F. of continuous use.

According to the present invention, these requirements have been met and the problem has been successfully solved commercially by the use of the novel process and forming die or mold described herein. The predetermined length of tubing of specified polyamide is mounted on the novel forming mold and baked under controlled stabilization conditions, and then cooled and the formed coil is removed from the mold, ready for use.

The invention will be more readily understood by reference to the accompanying drawing in which FIGURE 1 3,1 $7,344 Patented .lan. 14;, 1964 depicts, on a greatly reduced scale, a side cross-sectional elevation of an aluminum keg in which is mounted a tapping valve to Which is attached a siphon coil of the present invention. FIGURE 2 presents an enlarged side elevational view or" a siphon coil of the present invention, as attached to a tapping valve of the keg. FIGURE 3 illustrates a side View of the forming mold in which the plastic siphon tubing is indicated in broken lines, while FIGURES 4 and 5 show top and bottom end views, respectively, thereof. FIGURE 6 shows a side view of the mold with the upper split covering end removed and turned over the expose the two bottoms thereof. Similar numerals refer to similar parts in the various figures.

Referring again to the drawing, numeral ill represents generally the plastic siphon coil having one end 11 inserted ti htly into mounting 12 of tapping valve 13 in the head 14 of aluminum beer keg 15. It will be noted that free end 16 of coil 169 is disposed directly on sidebottom 17 of keg 15.

Coil Ill is made by taking a straight length of specified nylon tubing, say of 0.138"/O.128" internal diameter and 0.025 wall thickness, and mounting it on the forming mold, indicated generally as 13. Mold 18 comprises a length 19 of solid round core rod, preferably of anodized aluminum of, say 6%" length, the center portion (for about 2%") of which is provided with a continuous helical fin 2i), projecting about from core rod 19, and having a pitch of about 4 turns per inch. Fin (or fins) 20 is (or are) about in thickness.

Core 19 has, mounted on its top end, a split cylindrical cover, indicated generally as 21, and, on its bottom, a single piece sleeve cover 22. Cover 21 consists of piece 23 having hold 24 through which passes screw 25 fitting into threaded hole 26 of the core. Screw 25 thus serves to removably attach piece 23 to core 19. The other piece 27 of split cover 21 has an angular-shaped key 28, attached to the inside of piece 27 by set screw 29, which key rides partially in angular keyway 39 in end 19 of core 19. Keyway 30 is about wide and /8" deep at end 19', its vertical taper being such that it reaches the edge of core 19 about 1%" from end 19'. Cover 21 is about 2" long, and key 23 is deep enough to engage in keyway 30, but is short enough to leave free space 31 through which straight end 11 of tubing l9 may pass freely.

Bottom end cover 22 on core 19 also is provided with an inner key 32', held onto cover 22 by set screw 33, and designed to ride in a portion of keway 34 cut into end 19" of core 19. Keyway 32 also is about deep at end 19" and it reaches the peripheral edge of core 1? about 1%" from end 1;". Key 32 projects about at end 1W, and is tapered to allow passage, through free space 35, of straight end 16 of coil ll).

Fins 20 are about di apart, and ends 24) and Zll thereof are feathered so as to make a line contact with

inner edges

21 and 22; of covers 21 and 27', respectively. Rounded entrance slots 36-36 are provided at the inner edges of covers 21 and 22, respectively, immediately over emerging terminals 30' and 34 of keyways 3t? and 3 5-, respectively, to permit easy entry of tubing 19 into key-

Way spaces

31 and 35, respectively, and also to provide a /2" radius at end junctures Ill and 16', respectively, of siphon coil 10.

Coil 19 is formed by first removing piece 27 of cover 21, and then inserting end 16 of the pre-cut tubing piece through slot 37 of bottom cover 22, and through keyway space 35, until the proper amount (about A) of end 16 projects from end 19'. Then tubing 16 is wound in the spaces between helixes 20 on core 19, and finally around slot edge 36 of top cover piece 23, and into keyway 36 A short length 11 (about A") of the tubing will project beyond the upper end of core. 19. Finally, piece 27 of cover 21 is slipped over core 19 by sliding key 28 over the tubing in keyway 30, so that end 11 of the tubing is safely locked in space 31 of the keyway.

Mold 18, with coil 19 mounted thereon, now is ready for baking, This is done by placing the assembly in a baking oven for 1 to 1.1 hr. at 375390 F. This temperature is higher than the recommended specification temperature for safe usage of the resin, and some incipient softening takes place accompanied by a stabilization of the coil shape. However, there is no collapse of the tubing from the original round cross-sectional shape, due, in a great part, to the supporting eifort of fins 20. After the specified baking is completed, the assembly is removed from the oven and allowed to cool. Then, end 22 and piece 27 are Slipped off the ends of core 19, and coil is unwound from helix 20.

It will be noted that stabilization of the coil shape apparently takes place at the incipient softening temperature of the plastic, which temperature is about 90 to 100 F. higher than the recommended safe operating tempera- 2 ture for continuous use of the resin. Although a round core 19 is disclosed herein, it is to be understand that cores of other shapes may be employed, if desired.

I claim:

1. A mold for making a stable flexible coil with straight ends from a straight length of thermoplastic tubing, comprising a cylindrical core, a continuous helical fin spaced to accommodate one Width of said tubing and having a length about equal to the linear length of the desired coil and height substantially equal to the outer diameter of a tubing to be coiled and disposed around the center portion of said core, a tapered keyway beginning at the surface of said core near each end of said helix and protruding further into said core and terminating at the end of said core below the center thereof, a removable sleeve disposed over one end of said core, a rounded slot cut into the inner edge of said sleeve immediately over said keyway and far enough to accommodate an end of a tubing as it is disposed in said keyway, locking means on said sleeve for lateral locking of said sleeve on said core to prevent sidewise movement, and a similar removable sleeve disposed on the other end of said core.

2. A mold according to claim 1 in which the similar removable sleeve is split axially into twopieces, one piece being attachable to said core, and the other piece having lateral locking means coacting with its keyway to prevent sidewise movement.

3. A mold according to claim 1 in which the locking means on the first sleeve coacts with its keyway to prevent sidewise movement.

References (Zited in the file of this patent UNITED STATES PATENTS 312,590 Tyrell et a1 Feb. 17, 1885 694,220 Webster Feb. 25, 1902 2,225,026 Welsh Dec. 17, 1940 2,322,757 Ward June 29, 1943 2,363,826 Yellin Nov. 28, 1944 2,393,058 Pierce et a1. Jan. 15, 1946 2,478,861 Collins et a1. Aug. 9, 1949 2,491,857 Greiner Dec. 20, 1949 2,565,465 Arnes Aug. 28, 1951 2,573,300 Beaumariage et al. Oct. 30, 1951 2,586,763 Judisch Feb. 19, 1952 2,843,878 Berberich July 22, 1958 2,878,514 Nichols et al. Mar. 24, 1959 2,920,351 Hardesty et al Jan. 12, 1960 FOREIGN PATENTS 11,078 Great Britain May 4, 1897

Claims

1. A MOLD FOR MAKING A STABLE FLEXIBLE COIL WITH STRAIGHT ENDS FROM A STRAIGHT LENGTH OF THERMOPLASTIC TUBING, COMPRISING A CYLINDRICAL CORE, A CONTINUOUS HELICA FIN SPACED TO ACCOMMODATE ONE WIDTH OF SAID TUBING AND HAVING A LENGTH ABOUT EQUAL TO THE LINEAR LENGTH OF THE DESIRED COIL AND HEIGHT SUBSTANTIALLY EQUAL TO THE OUTER DIAMETER OF A TUBING TO BE COILED AND DISPOSED AROUND THE CENTER PORTION OF SAID CORE, A TAPERED DEYWAY BEGINNING AT THE SURFACE OF SAID CORE NEAR EACH END OF SAID HELIX AND PROTRUDING FURTHER INTO SAID CORE AND TERMINATING AT THE END OF SASD CORE BELOW THE CENTER THEREOF, A REMOVABLE SLEEVE DISPOSED OVER ONE END OF SAID CORE, A ROUNDED SLOT CUT INTO THE INNER EDGE OF SAID SLEEVE IMMEDIATELY OVER SAID KEYWAY AND FAR ENOUGH TO ACCOMMODATE AN END OF A TUBING AS IT IS DISPOSED IN SAID KEYWAY, LOCKING MEANS ON SAID SLEEVE FOR LATERAL LOCKING OF SAID SLEEVE ON SAID CORE TO PREVENT SIDEWISE MOVEMENT, AND A SIMULAR REMOVABLE SLEEVE DISPOSED ON THE OTHER END OF SAID CORE.