US2649619A - Apparatus for manufacturing dipped rubber articles - Google Patents

Description

E. S. KILLIAN Aug. 25, 1953 APPARATUS FOR MANUFACTURING DIPPED RUBBER ARTICLES 2 Sheets-Sheet 1 Filed Feb. 4, 1950 INVENTOR. EDWAPD S. [fill/AN E. S. KILLIAN Aug. 25, 1953 APPARATUS FOR MANUFACTURING DIPPED RUBBER ARTICLES- Filed Feb. 4, 1950 2 Sheets-Shet 2 INVENTOR. WARD S/f/LL/A/V 147'; OE'NEYS mw B Patented Aug. 25 195 3 UNITED STATES PATENT OFFICE APPARATUS FOR MANUFACTURING DIPPED RUBBER ARTICLES Edward S. Killian, Akron, Ohio Application February 4, 1950, Serial No. 142,487

I 6 Claims. 1 V

The present invention relates generally to the molding art and is moreparticularly concerned with a novel method of making thin dipped articles from a relatively viscous dipping bath of latex or the like, and with unique apparatus implementing that method.

In the manufacture of balloons and similar relatively heavy dipped rubber goods which do not command the higher prices of lighter goods, like prophylactics, it is important that costs be reduced to and maintained at a minimum. Accordingly, the decomposition of the latex film must be carried out in a single dipping operation. This may be accomplished by using a viscous dipping bath and providing a coating of a suitable coagulant on the form. However, the dipping form tends to drag air into such a bath with the result that bubble inclusions are formed in the dipping film and the final articles eventually emerge from the production equipment with holes or thin spots traceable to such inclusions.

I have discovered how defects in these articles due to bubbles in the dipping bath can practically be eliminated and how such air drag-in can be materially reduced. Furthermore, I have discovered how these results can be obtained without any loss of time or decrease in production rate. Still further, these results are readily obtainable without in any way diminishing the value, utility or quality of the goods and may be secured in an entirely automatic manner by using novel apparatus of any invention which is economical to build, install and operate.

The method of this invention is predicated upon my discovery that by bringing dipping form into a dipping bath in a particular and critical man ner, the tendency of bubbles of air to become trapped in the film depositedon the formwill be substantially entirely eliminated even though the transverse rate of travel of the form through the bath is relatively great, as his inthecase of the conventional continuous dipping techniques.

More particularly, in the preferred practice of this invention an elongated dipping form disposed at an angle of about 90 to the surface of a dipping oath is introduced substantially endwise into the bath. The form may be rotating at the time that it comes into contact with the bath but preferably is not rotating then. However, in its travel through the bath it is immaterial whether the form is rotating. If the form is rotating in such travel, the rate of rotation is substantially reduced as the form is withdrawn fromthe bath, and in some instances its rotation at this stage may be stopped gradually or abruptly or the direction of rotation of the form may even be reversed.

The apparatus of my present invention, which enables the automatic carrying out of the foregoing method, comprises in its broadest aspects an endless moving conveyor, an arm projecting laterally therefrom, a dipping form, and a conhector pivotally carrying the form and rotatably carried by the arm. The guiding of the dipping form prior to, during, and after the dipping operation may be accomplished manually, but preferably guide means is provided to engage the con hector and shift it relative to the arm to various positions, as required in accordance with the said method as outlined above. Further, a frame is provided to support the conveyor and constitutes a pair of spaced rotatable sprocket wheels to engage the conveyor, and driving means associated with the conveyor and the sprockets isprovided to move the conveyor continuously at a predetermined rate around its closed course.

A better understanding of the method and apparatus of this invention may be gained by those skilled in the art upon consideration of the detailed description set forth below, reference being had to the drawings accompanying and forminga part of this specification in which:

Fig. 1 is a fragmentary, side elevational view of apparatus embodying this invention in a preferred form;

Fig. 2 is a fragmentary, top plan view of a portion of the upper throw of the conveyor of Fig. 1 showing two opposed pairs of dipping forms and means connecting them in the assembly and supporting and guiding them;

Fig. 3 is a vertical sectional view of the conveyor apparatus of Fig. 1 taken on line 33 of Fig. 2;

Fig. 4 is a fragmentary, vertical sectional View similar to Fig. 3, but showing a dipping form in alternative position as indicated above the upper portion of the sprocket in Fig. 1;

Fig. 5 is an enlarged, fragmentary, side elevational view of the apparatus of Fig. l at the sprocket, showing how the forms are guided in their travel around the sprocket and into the dipping bath vessel and showing a guide rail supportframe; 7 i

Fig. 6 is a fragmentary, side elevational view of apparatus embodying the present invention in another form;

Fig. 7 is a fragmentary, plan view of a portion of the conveyor belt of Fig. 6 showing the details of construction of the links of said belt;

Fig. 8 is a fragmentary, sectional view taken on line 8-8 of Fig, '7; and,

Fig. 9 is a fragmentary, side elevational view of the portion of the apparatus of Fig. 6 adjacent to discharge end of the dipping vessel, showing novel guide means for the forms effective to change the rate of rotation of the forms during the first stage of film drying.

With reference to Figs. 1 to 5, inclusive, the present apparatus comprises an endless conveyor belt l0 made up of a plurality of individual links i I pivoted together by means to be described for bending of the belt as necessary in traveling around a sprocket 13 supported rotatably on a shaft l6 and driven by any suitable motor means (not shown). Another sprocket which is not illustrated, but suitably corresponds in shape and size to sprocket I3, is provided to support the belt at the other end of its course.

A dipping bath vessel i5 constituting an elongated open top tank is disposed below and adjacent to sprocket l3 and extends toward another sprocket of the assembly to afiord adequate contact of a dipping bath 16 in said vessel with conventional dipping forms I! carried by the conveyor. Guide means to govern the position of the dipping forms during the course of their travel to, through and from the dipping bath complete the general combination of this apparatus and constitute several independent and separate, but

of the way around sprocket i3, these rails being disposed on each side of the belt and paralleling each other so that each may serve to guide one of the two sets of forms I! extending from opposite sides of the conveyor, as indicated in Figs. 2 and 3.

Another part of this means constitutes another pair of angle iron rails 22 which extend along the upper throw of belt [0, around sprocket l3 and substantially the entire length of vessel 15 for engagement with the shank of each form to produce rotation of the forms by virtue of the relative motion of the belt to rails 22. In the vicinity of the top of sprocket l3, rails 22 are gradually turned through 180 around their longitudinal axes and elevated above belt H] to effect lifting of forms I! from a substantially horizontal to a substantially vertical position. Rails 22 are shaped to define an arc of approximately 180 around sprocket [3, said are and sprocket having a common center in shaft l4. Still another set of angle iron rails 24 is provided to cooperate with rails 22 in holding forms I! in other than horizontal position, as above described, and to guide these forms in their travel around the lower portion of sprocket i3, through bath l6 and out of vessel IE to the other sprocket of the assembly. Thus, rails 24 have one of their ends along the upper throw of conveyor [0 and they are disposed between the sides of the conveyor for engagement with the inner sides of the forms, as shown in Fig. 4. Rails 24 extend lengthwise of the conveyor course between the lower throw of belt H] and the pend from the ceiling and in other cases extend upwardly from the floor of vessel 15.

A typical link ll of belt I0 comprises a casting 26 in the general form of a yoke having an up standing plate-like portion 21 secured to its midportion for attachment of the link to means to be described for carrying dipping forms H. The bridge of the yoke comprises a generally cylindrical body 28 spaced from portion 2! and a pair of legs 29 extending divergingly from body 28. Body 28 has a longitudinally-extending axial aperture and legs 29 are transversely apertured in their free ends so that an apertured body 28 of an adjacent link may be received between the ends of legs 29 with the apertures of these parts in register to receive a connecting pin 32. The longitudinal dimension of body 28 will accordingly be slightly less than the distance separating the apertured ends of legs 29 of each link. Link II is provided further with keeper means comprising hook lugs 3c welded to opposite edges of portion 21 to engage annular flanges 33 on the inner ends of sleeves 31 carried by a bar 34, as indicated in Fig. 4.

The dipping form securing means mentioned above comprises said elongated rod 34 extending transversely of the link and fastened by means of a pair of blocks 35 bolted to link portion 27, the ends of the rod being disposed on opposite sides of the link. Sleeves 31 of inside diameter approximating the outside diameter of rod 34 are carried rotatably on each end of the rod and each of these sleeves'in turn, is provided with an elongated guide plate or blade 38 to run on one of rails 21! and with a transversely apertured end portion for receipt of a pin or bolt.

As indicated above, form I! is constructed in accordance with the practice common in the art, the shank thereof being hollow and of Bakelite or the like and carrying rotatably an axle member 39 having an aperture in its free end for registry with the transverse aperture in a sleeve 31. A nut and bolt assembly 4| is normally used, as shown in Fig. 2, to secure these said apertured parts together for pivotal motion of the clipping form relative to the sleeve.

In normal use, the device of Fig. 1 is operated Y continuously, sprocket l3 rotating at a predetermined rate and belt l0 running around its course so that the forms are carried through the various stations, including the dipping station in sequence to produce the desired dipped articles. Tracing the course of travel of one of these dipping forms, as it approaches sprocket I3 the form is moved gradually from a substantially horizontal position to a substantially vertical position, the guide rails being appropriately shaped and disposed, as described above, to effect this motion, the guide blades 38 running on rails 20 while the shanks of the forms are running on rails 22 and/ or rails 24. As the form moves with the belt around this sprocket, it may be rotated by engagement with one or the other of rails 22 and 24 which are spaced apart slightly more than the diameter of the roll shank. Approximately half-way around the sprocket, rail 20 terminates, allowing the weight of the form to turn sleeve 31 on rod 3d so that the form assumes a substantially vertical position just prior to entering the dipping bath. Rails 22 and 24 guide the form in its travel through the bath.

The apparatus of Fig. 6 generally resembles that of Fig. 1 in that a conveyor belt 53 carrying dipping forms 5| is provided and this belt is driven by motor means (not shown) through a shaft 53 and a sprocket 54 carried by and keyed to the shaft. An elongated dipping tank 56 has an end disposed below sprocket 54 and extending toward the opposite end of the conveyor course where suitably a second sprocket (not shown) is provided to support the conveyor.

Also, inner guide rails 58 are provided on both sides of belt 50 and extend along the upper throw portion of the conveyor course and about one quarter of the way around the outside of sprocket it, after the manner of rails 29, and have their other end near the discharge end of vessel A second set of angle iron rails 8d (Fig. 9) are provided on opposite sides of belt iii: to engage the shanks of forms and cause their rotation after the manner of rails 22. Rails are curved away from the mid-portion of sprocket 5 and spaced below belt 59 around the lower part of sprocket 5 and across the length of tank 5%, terminating adjacent to the discharge end thereof, to engage the form shanks just before and during their travel through the dipping bath. Another part of angle iron rails BI is disposed, like rails 2s, between the sides of belt 51') beginning where rails 60 turn-outwardly from sprocket 5d and extending parallel with said rails se to a point near the discharge end of tank 56, to engage the form shanks and cooperate with rails 58 to guide the forms through the dipping bath.

The structure of belt 50, likewise is similar to that described above, the links being in the form of yckes. This conveyor belt, however, is so constructed as to be capable of flexing two ways. An individual link 55 of this belt thus comprises a cylindrical body t6 having a longitudinally extending aperture and a pair of opposed parallel legs is? extending from the body and having free ends provided with apertures for registry with the aperture in another body 5'5 disposed between the ends. Member 21 of the typical link of the Fig. 1 conveyor is eliminated in this structure and forms 5| are secured to the belt by means of outwardly extending trunnion pins t9 secured to the two leg members between body and the free ends thereof, as indicated in Figs. 7 and 8. Sleeves H! corresponding to sleeves 3? receive these pins and are held in engagement therewith by means of blocks '52 screwed to the tops of the legs and bearing on the sleeves.

Adjacent to the discharge end of the vessel and thereabove a small sprocket is provided to run above the lower throw of belt 58 and guide the belt in its travel upwardly to lift the forms from the clipping bath. A second small sprocket it approximately the size of the first one is disposed slightly above the first one and further along the course of the conveyor belt to run below said belt and cooperate with sprocket to lift the belt clear of vessel 56 and guide the belt in its further travel along its lower throw course.

Two pairs of pulleys l8 and 19 are disposed adjacent to and below and on opposite sides of the belt and connected by two V-belts 80 which travel a course paralleling the course of belt 59 between sprockets l5 and H5. Belts 8!] thus engage the shank of a form 5| as they are brought adjacent to the discharge end of the vessel, lifting the form from a substantially horizontal position to a substantially vertical position between sprockets l5 and 16 and delivering the forms onto sections of rails Gil beginning adjacent to sprocket it as shown in Fig. 9. Pulleys l8 and it are driven by any suitable means such as motors (not shown) and the pulleys of each pair are mounted with their axes at sharp angles to each'other'to effect the desired motion of the form along this segment of its travel. Regulation of. the rate of V-belt travel may be obtained by manual or automatic means, as those skilled in the art will understand, and may be regulated to the rate of the conveyor belt travel to increase or decrease the rate of rotation to the dipping forms as they emerge from the dipping bath, and even to stop such rotation, as

when belts 8E! and belt 50 travel at substantially the same rate.

Having thus described the present invention so that those skilled in the art may be able to understand and practice the same, I state that what I desire to secure by Letters Patent is defined in what is claimed.

What is claimed is l. Apparatus for manufacturing thin, dipped rubber articles comprising an endless conveyor, an arm secured to and projecting laterally from the conveyor, a dipping form, and means for connecting the form to the arm, said form having a shank rotatable relative to the form and having an aperture in its free end, and said means including a sleeve receiving the arm and rotatable relative thereto and having an opening in its free end for registry with the aperture in the free end of said shank, and a bolt to extend through registered aperture and opening and holding the sleeve and shank pivotally together.

2. Apparatus for manufacturing thin, dipped rubber articles comprising an endless conveyor, a plurality of arms spaced apart and secured to and extending laterally from the conveyor, a lurality of dipping forms, a plurality of connectors pivotally carrying the forms individually and rotatably carried by said arms, stationary means to engage the forms and cause rotation. of them relative to the conveyor as the forms. traverse a predetermined portion of the conveyor course, and means engaging said connectors for shifting them relative to said arms to vary the; position of the forms relative to the conveyor.

3. Apparatus for manufacturing thin, dipped; rubber articles comprising an endless conveyor, a dipping form, and means for connecting theiorm to the conveyor, said form having a shank rotatable relative to the form and having a freeend, and said means including a connector rotat-- ably carried by the conveyor and projecting. laterally therefrom and having a free end for con-- nection to the free end of said shank, and means. connecting pivotally together said free ends oi the shank and the connector.

4. Apparatus for manufacturing thin, dipped, rubber articles comprising an endless conveyor, a dipping form, means for connecting the form to the conveyor, and stationary means disposed adjacent to said endless conveyor to' engage said form and cause rotation of the form relative tothe conveyor as the form traverses a predetermined portion of the conveyor course, said form having a shank rotatable relative to the form and having a free end, and said connecting means including a connector rotatably carried by the conveyor and projecting laterally therefrom and having a free end for connection to the free end of said shank, and means connecting pivotally together said free ends of the shank and the connector.

5. Apparatus for manufacturing thin, dipped rubber articles comprising an endless conveyor, a dipping form, means for connecting the form to the conveyor, said form having a shank rotatable relative to the form and having a free end, and said means including a connector rotatably carried by the conveyor and projecting laterally therefrom and having a free end for connection to the free end of said shank, means connecting pivotally together said free ends of the shank and the connector, and means engaging said connector for shifting it rotatably relative to the conveyor to vary the position of the form at predetermined locations along the conveyor travel course.

6. Apparatus for manufacturing thin, dipped :rubber articles comprising an endless conveyor, a dipping form, means for connecting the form to the conveyor, said form having a shank rotatable relative to the form and having a free end, and said means including a connector rotatably carried by the conveyor and projecting laterally 10 tical position.

EDWARD S. KILLIAN.

References Cited in the file of this patent UNITED STATES PATENTS 15 Number Name Date 1,991,118 Raiche Feb. 12, 193 2,260,854 Killian Oct. 28, 1941 2,351,202 Hahne June 13, 1944

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