US3589884A

US3589884A - Glass bulbs and the like containers provided with self-breakable necks

Info

Publication number: US3589884A
Application number: US804554A
Authority: US
Inventors: Raymond Guiriec
Original assignee: LABORAVER SARL
Current assignee: LABORAVER SARL
Priority date: 1968-03-05
Filing date: 1969-03-05
Publication date: 1971-06-29
Anticipated expiration: 1988-06-29
Also published as: DK127970B; LU58098A1; IL31727A0; DE1910942A1; SE359286B; FR1583432A; DE1910942B2; CH498782A; GB1228122A; NL146043B; BE729162A; NL6903251A

Abstract

A METHOD AND MEANS FOR OBTAINING A SELF-BREAKABLE BULB OR PHINAL, THAT IS A BULB OR PHIAL REQUIRING NO FILE FOR CUTTING IT OPEN; TO THIS END, THE EDGE F A BLADE OF SILVER, ALUMINIUM OR ALUMINIUM ALLOY IS URGAED AGAINST THE NECK OF THE CONTAINER DURING ITS COOLING SO AS TO LOCALLY INCREASE ITS CAPACITY OF THERMIC DISSIPATION AND TO CNSEQUENTLY PRODUCE AN INTERNAL STRAINING LEADING TO A GREATER BRITTLENESS. ADVANTAGEOUSLY THE BULB OR THE LIKE CONTAINER IS CAUSED TO REVOLVE ROUND ITS AXIS DURING THE PROCEDURE SO AS TO ENSURE AN ANNULAR MARKING WHEREBY THE NECK MAY BE BROKEN IN A CLEAN MANNER BY A FLEXIONAL STRESS EXERTED ON IT WHATEVER THE DIRECTION OF THE STRESS MAY BE.

Description

June 29, 1971 GUIRlEc 3,589,884

GLASS BULBS AND THE LIKE CONTAINERS PROVIDED WITH SELF-BREAKABLE NECKS Filed March 5, 1969 K4 YMOA/A Gum/Ea United States Patent 3,589,884 GLASS BULBS AND THE LIKE CONTAINERS PROVIDED WITH SELF-BREAKABLE NECKS Raymond Guiriec, Longjumeau, France, assignor to Socit a Responsabilit Limite Laboraver, Longjumeau, France Filed Mar. 5, 1969, Ser. No. 804,554 Claims priority, application France, Mar. 5, 1968,

Int. C1. C63]; 21/00 US. Cl. 65-105 2 Claims ABSTRACT OF THE DISCLOSURE A method and means for obtaining a self-breakable bulb or phial, that is a bulb or phial requiring no file for cutting it open; to this end, the edge of a blade of silver, aluminium or aluminium alloy is urged against the neck of the container during its cooling so as to locally increase its capacity of thermic dissipation and to consequently produce an internal straining leading to a greater brittleness. Advantageously the bulb or the like container is caused to revolve round its axis during the procedure so as to ensure an annular marking whereby the neck may be broken in a clean manner by a flexional stress exerted on it whatever the direction of the stress may be.

The present invention has for its object glass bulbs, phials and the like containers provided with one or two necks adapted to be broken so as to allow the contents to be used. "A

To open such bulbs a slight cut is generally made by means of a file after which a flexional stress is exerted on the outer end of the :bulb beyond the neck so as to open the latter. It has already been proposed to cut out the requirement leading to the use of a file by providing self-breakable bulbs. The French Pat. 1,093,767 dated Feb. 22, 1954, discloses a method for executing such self-breakable bulbs provided with a throttled neck by first weakening the bulb at a point of the neck by means of a transverse scratch or notch on the outer surface of the neck. The location of the notch or scratch is advantageously defined by a colored product which is caused to melt over the surface of the neck during the annealing procedure. Said prior patent also discloses the production of internal stresses within the glass structure by applying a cold implement over the neck which is still in a hot condition or else a product adapted to melt while its coetficient of expansion is higher than that of the bulb. These last two modifications have been referred to however as less satisfactory than the scratching of the neck and in fact this last method was considered as the sole one suitable in the case of conventional bulbs with a single neck. It requires however the use of a colored product which can melt easily and which melts during the annealing procedure, which means auxiliary operations and leads to the production of exaggeratedly brittle bulbs or conversely of unbreakable bulbs according as to whether the notch is too deep or too shallow.

The French Pat. 1,040,588 dated July 27, 1950, disclosed on the other hand the execution of self-breakable bulbs by means of a stressing of the glass forming the neck as provided by the application, over a comparatively reduced area or along a line, of a readily meltable material the shrinking coefiicient of which differs from that of glass, said material being caused to melt during the annealing of the bulb. This method requires an objectionable annealing which leads to further work and handling and "ice such further handling may be a cause of breaking and increase in cost.

The present invention has for its object to cut out the above drawbacks by producing through a single simple operation the inner stressing of the glass and the marking of the section to be broken, before use without any other ancillary operations.

The method provided by the invention consists in applying against the .glass forming the bulb neck, while the bulb is at a temperature ranging between about and C. a thin annealed blade or section of silver, aluminium or of an aluminium alloy.

Said metal blade or section which is laid on the bulb at room temperature produces a straining of the glass material which furthers the breaking of the neck and leaves an indelible mark on the glass; this cuts out the necessity of any subsequent marking by means of a fusible material, which marking is always a lengthy. operation and requires an annealing, while furthermore it risks being inaccurate.

The method according to the invention provides thus multiple advantages chiefly as concerns speed and simplicity when compared With prior methods.

According to a preferred embodiment, the method consisting in straining and marking one or both ends of the bulb is incorporated with the actual production of the bulb and is performed during the cooling stage following the drawing out and cutting off of the bulb just before the ejection of the finished bulb.

According to an auxiliary feature of the invention, the thin blade is applied over the bulb while the latter revolves through at least one revolution round its axis so as to leave a mark surrounding entirely the neck of the bulb, whereby this neck may be readily broken off by a bending stress exerted in any direction whatever.

The machine for executing the method according to the invention is constituted by a bulb-producing machine of the so-called Well-known merry-go-round drawing out type wherein the glass tubes are heated locally and then drawn out to form the necks of the bulbs or phials which are then cut off, one end thus formed being closed and the other remaining open. According to the invention, said machine is provided at a point ahead of the drawing out station with one or two blades made of annealed silver, aluminium or aluminium alloy and the edge of which is urged elastically against the path followed by one or both bulb necks formed by drawing the successive bulbs out of the original tube.

The invention will now be disclosed with further detail, reference being made to the accompanying drawings wherein:

FIG. 1 is an elevational view of a bulb obtained in accordance with my invention,

FIG. 2 is a diagrammatic elevational view of the station of the bulb-producing machine at which a metal deposit is obtained so as to mark the necks of a bulb, said cross-section being executed along line II-II of FIG. 3.

FIG. 3 is a diagrammatic plan view of the station as seen under the horizontal plane designated by III-III in FIG. 2. The bulb 1 is of the standard type including two straight tapering necks, the end of the neck 2 being closed by melting said end 2 to form a bead 3 on the latter while the other end 4 remains open for its subsequent filling before welding. According to the invention, each neck of the bulb is provided with annular peripheral traces of annealed silver, aluminium or aluminium alloy.

The merry-go-round of the conventional bulb-producing machine includes a lower annular plate 6 and an upper annular plate 7, both plates being driven into rotation in the direction of the arrow F while the tubeclamping members 8 and 9 are driven in the direction of the arrows ;f. The members 8 engage the original glass tubes 10 while the members 9 engage the already formed bulb, the neck-shaped end 2 of which is already closed by welding. The part of the tube 10 extending between the two tube-clamping members has been heated at a preceding station by means of a blow-pipe and has been stretched so as to form the neck 4 on the bulb 1 and the neck 2 on the lower end of the remainder of the tube 10, the connection between the tube and the bulb being cut off just under the lower sealed end of the tube 10'.

In registry with the cooling station illustrated in FIGS. 2 and 3, at which station the temperature of the glass is equal to 150 C. or thereabouts, there are fitted two silver blades '11 extending in the horizontal plane which has been selected for the location of the breakable section of the neck during operation. These blades are carried by horizontal arms pivotally secured at 13 and urged towards the vertical axis of the glass tube and bulb by the springs 14, the movement of said arms 12 being limited by stops 15.

The neck 4 of the bulb 1 and the neck 2 at the lower end of the tube 10 hold the blades 11 against further inward motion so that said blades leave on the glass by reason of the rotary movement and temperature of the latter a clear apparent trace 5. Such a metal trace furthers heat exchange with the outer atmosphere whereby a local cooling of the underlying glass section is accelerated and consequently an inner strain appears in said section. When a flexional stress is exerted on the tip of a bulb when closed, the neck breaks along a clean line defined by the trace 5.

Obviously numerous modifications may be brought to the above embodiment given by way of example, without widening the scope of the invention as defined by the accompanying claims.

What I claim is:

1. A method of providing a self-breaking neck on a hollow glass article, comprising urging a thin member of a metal selected from the group consisting of annealed silver, aluminum and aluminum alloy against the neck of a hollow glass article while the neck is at a temperature of about 100 to 180 C. and rotating said article through at least one complete rotation about the axis of its neck during the application of said member so as to deposit on the glass a band of said metal that encircles the neck and that accelerates local cooling of the underlying glass thereby to form on said neck an annular stressed section that allows the neck to be broken readily by flexural stresses in any direction.

2. A method as claimed in claim -1, and forming said article from a glass tube and drawing out and cutting off the article from said tube and thereafter performing said urging and rotating steps while the article is cooling.

References Cited UNITED STATES PATENTS 2,641,870 6/1953 Eisler 65-174X 2,918,753 12/1959 Pichter 65-174X 3,215,345 11/1965 Ferguson 65-174lUX FOREIGN PATENTS 409,283 4/1934 Great Britain 65-108 815,259 6/1959 Great Britain 65-108 545,605 7/1956 Italy 65-109 608,026 9/1960 Italy 65-174 1,270,841 7/1961 France 65-105 644,410 3/1937 Germany 65-115 FRANK W. MIGA, Primary Examiner US. Cl. X.R.