US 2286117 A
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2 Sheets-Sheet 1 ATTORNEY A. E. SIDNELL METHOD OF MAKING A PE RFORATI E ARTICLE Filed May 9, 1939 B 5 5 m V A F B J 4 J Q u 7 G T n 1 Z W m n W 1 Av. L 2 K 5 Eu June 9, 1942.
A. E. SIDNELL METHOD OF MAKING A PERFORATE ARTICLE June 9, 1942.
Filed May 9, 1939 2 Sheets-Sheet 2 ALBERT E.-
INVENTOR S noneu.
' ATTORNEY Patented June'9, 1942 Albert E. Sidnell, Akron, Ohio, assignor to Seiberling Latex Products Company, Barberton, Ohio, acorporation of Ohio Application May 9', 1939, Serial No. 272,586
This invention relates to perforate molded articles of vulcanized rubber and in particular relates to perforate bags of elastic or resilient material, such as rubber, of the type used by laundries for containing batches-of clothes to be washed or otherwise treated, and to methods and apparatus for manufacturing the same.
Heretofore, in the manufacture of such perforate rubber laundry bags or like articles ithas been necessary first to vulcanize the bag to shape in amold and then,v by means of expensive punching dies and heavy punching presses, to punch the perforations in the bag. Obviously, such procedure involved high production costs. Also, in the past the core used in molding the bag has been made relatively thin and fiat with curved edges of small radius extending about the same to reduce the cost of the core and to reduce the weight thereof for more efllcient handling by press operators. This produced a bag having edge portions normally curved about a small radius and along which splitting occurred, 1 due to flexing and stretching of the bag at the edge portions when packed with clothes.
An object of the invention is to provide an improved perforate article of the character described such as a rubber laundry bag orthe like, and to provide simple economical procedure and apparatus for producing the same. I
Another object of th invention is to provide a substantially flat vulcanized rubber bag of the character described requiring the use of a flat and therefore light core, but having relatively large rounded edge portions forming the curved edge portions of the bag with a comparatively large radius to obviate splitting of the bag along these edgeswhile the bag is in service.
These and other object of the invention will be manifest from the following brief description andthe accompanying drawings. Of the accompanying drawings:
Figure 1 is a transverse cross-section, partly broken 'away, through a mold as used for vulcanizing an improved laundry bag embodied in the invention. Y
Figure 2 is an enlarged fragmentary crosssection taken on line 2-2 of Figure 1. Figure 3 is a view showing a portion of a bag which has been removed from the mold after manner of mounting the bag while still wrongside out, for removal of the nubs.
Figure 6 is an enlarged fragmentary crosssection taken on line 6-6 of Figure 5.
Figure 7 is a plan view of a'finished bag in right-side-out condition.
Figure 8 is an enlarged cross-section taken on line 8-8 of Figure 7.
Referring to Figures 1 and 2 of the drawings,
the numeral I0 designates the lower .section, II
the upper section, and ii the intermediate seci 'tion or core of a laundry bag mold. The manner of utilizing this mold for shaping plastic sheet rubber therein to provide a laundry bag or like article is well-known in the art.
The respective mold sections preferably are designed to form substantially flat bag I3 having the adjacent walls thereof relatively close together so as to reduce thethickness of the core, and hence the weight thereof, thereby facilitating more efflcient handling of the core by press To prevent splitting of bag l3a1ong' the edge portions thereof, as described, the reoperators.
spective mold sections preferably are designed to form enlarged bead or rounded edge portions about the bag, as indicated at It (see Figure 1). Thus the core 82 may be of relatively thin, light weight construction and yetforms rounded edge portions of large radius on the bag for the purpose above referred to.
For forming perforations in the bag, the upper and .lower sections ll and 52 may be provided with a plurality 'of pins [5, is which project from the inner faces of said sections, the projecting ends of the pins being arranged to be received in correspondingly arranged recesses l6, IS in opposite sides of core l2, when the sections are in the relation shown in Figures 1 and 2. A very slight clearance is allowed between pins l5 and the sides of recesses It, the clearance bestj suited for the present purposes having been found to be approximately .005 inch. Also, when the sections are in the press-closed positions thereof, there preferably is allowed a substansmooth edges, as will be subsquently described.
preferably extending angularly of those on theother side, so as to produce similarly angularly disposed ribs 2|, 2| on the inside faces of the bag. These ribs 2|, besides reinforcing. the bag,
.prevent the sides of th bag from sticking together.
As best shown in Figures 5 and 6, after the bag I 3 has been removed from the vulcanizing mold it is turned wrong-side-out to present nubs I 9 to the exterior thereof and then it is stretched over a suitable fiat board or form 22. By rubbing suitable straight edged tool or scraper or knife 23 over the surfaces of the bag to engage under nubs IS, the latter may rapidly be separated from the bag, by virtue of the thin web l9 being easily disrupted or torn away from bag adjacent the perforations.
When the nubs l9 have been removed from both sides of the bag l3 the latter is turned right sideout to present the reinforcing ribs H to the exterior of the bag, as shown in Figures 7 and 8.
Thus has been provided a simple, economical procedure and apparatus for producing an improved perforate rubber article, such as the rubber laundry bag shown and described. It is to be understood that the perforations or other openings formed in the article may be any desired shape. For example, rectangular openings I 1, usually provided adjacent the closure end of the bag to receive suitable closure fastening means (not shown) may be formed in the same manner as the perforations I'I.
Modifications of the invention may be resorted to without departing from the spirit thereof or the scope of the appended claims.
What is claimed is:
1. 'That method of making perforate bags which comprises providing a core with recesses therein where perforations are desired, forming and vulcanizing rubber or the like about the core with openings by pressing the rubber into said recesses, the bag thus formed having projecting nubs on-the inside surface thereof pressed out of said openings and connected to said edges of said openings by comparatively thin webs of rubber, removing the bag from said core, turning inside out, and disrupting said webs of rubber to remove said nubs from the surfaces of the bag.
2. That method of making perforate bags which comprises providing a core with recesses therein where perforations are desired, forming and vulcanizing rubber or the like about the core with openings by pressing the rubber into said recesses, the bag thus formed having reinforcing ribs circumsoribing said openings and having projecting nubs on the inside surface thereof pressed out of said openings and connected to said edges of said openings by comparatively thin webs of rubber, removing the bag from said core, turning inside out, and disrupting said webs of rubber to remove said nubs from the surfaces of the bag.
3. That method of making perforate flexible rubber articles which comprises forming an article with one or more openings having one or more hollow nubs connected thereto by thin, frangible, elastic webs of rubber about the edges of the openings, mounting said article on a support with said nubs extending outwardly and rubbing the outer surface of said article to flex and exert tension upon said frangible elastic webs to tear the nubs free from the article.
ALBERT E. SIDNELL.