Inflatable rubber goods

Jan. 6, 1942. j. _H jqhnson 2,269,342

INFLATABLE RUBBER GOODS Filed May 31, 1938

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72/ β John H. John son

Patented Jan. 6, 1942 2,269,342

UNITED STATES PATENT OFFICE

2,269,342

INFLATABLE RUBBER GOODS

John H. Johnson, Toronto, Ontario, Canada, assignor to K &amp; W Rubber Corporation, Delaware, Ohio

Application May 31, 1938, Serial No. 210,876

Claims. (Cl. 5—350) rubber sheets 2 and 3, to permit the marginal portions thereof to contact, and such paper sheet is provided with openings 5 at a plurality of suitably spaced points which may be representative 5 of the tufting zones 6, and discs 7 and 8 of rubber are placed concentric with the openings 5 on respective sides of the separating sheet 4 as illustrated in Figure 3.

Discs 9 and 10 formed of a suitable strong 10 fabric and of smaller size than the discs 7 and 8, are interposed respectively between said discs of rubber and the outer rubber sheets 2 and 3 and concentrically of the openings 5, and extra reinforcing rings 11 of rubber may, in cer15 tain cases, be applied on the outward side of the sheets 2 and 3 to provide a more enhanced thickening in the peripheral zone of the fabric inserts.

When the assembly has thus been effected heat and pressure are applied in a suitable man20 ner and the strata of rubber and fabric in register with the openings 5, as well as the marginal portions of the sheets 2 and 3, will be permanently united and bonded under vulcanizing conditions so that a locally reinforced zone, such as 25 shown in Figure 4, will be produced.

In Figures 5 and 6 the above principle of reinforcement is shown applied to the marginal edge portion of a pair of rubber sheets (2 and 13, the fabric being in the form of a pair of ^:) strips (4 and (5, which, as shown in Figure 5, have placed therebetween, a pair of rubber strips 16 and (7 and the separating paper strip 4' extends between the latter for a suitable portion of the width, leaving the remaining portions free ³ to vulcanize together and to permanently bond with the fabric and with the marginal portions of the outer sheets, resulting in an effectively reinforced edge construction as shown in Fig₍ ure 6.

⁴⁰ In Figures 7 and 8 a further modified form of connection is provided between superimposed sheets 12' and 13', in that the fabric reinforcement is shown as comprising a single strip of fabric (8 doubled upon itself and having two ^4,1 strips of rubber 16' and 17' placed therebetween and separated for a substantial portion of their width by the paper-separating strip 4'. This results in a reinforced connection as shown in _ Figure 8.

’ It will be understood of course that the fabric may be first treated or coated with rubber compound in any well known manner prior to incorporation in the structure and while I have _r_ shown this preferred form of structure incorpor^C,J ating the present invention, the invention is not

The principal objects of the invention are to obviate inherent weaknesses in an inflatable structure such as used in mattresses and cushions or the like and to provide local reinforcements at the points of greatest strain, to thereby prolong 5 the effective life of the structure.

The principal feature of the invention resides in the novel construction and manner of fabricating an inflatable structure of the multiwall type, whereby a flexible reinforcing agent 10 is incorporated in the zone where the multiwalls are connected by vulcanization.

In the drawing,

Figure 1 is a miniature perspective view partly in section showing a pneumatic mattress con- 15 structed in accordance with the present invention.

Figure 2 is a transverse sectional view through the inflatable element of Figure 1.

Figure 3 is an enlarged fragmentary elevation 20 showing a preferred relative arrangement of the component parts of one of the locally reinforced zones.

Figure 4 is a transverse sectional view through the locally reinforced zone after vulcanization and in substantially inflated condition.

Figures 5 and 6 illustrate the present invention applied to the edge construction of an inflatable device.

Figures 7 and 8 show a modified form of re- ·^:)inforced edge connection between respective walls of an inflatable device.

In my earlier United States Patent 1,970,803, granted August 21, 1934,1 disclosed an inflatable structure formed from superimposed sheets of ° rubber separated in certain zones by the interposition of a sheet of paper or the like, so that only the zones not so separated would vulcanize together to form a multiplicity of inter-connected air cells. ⁴⁰

It has been found in practice that the greatest strains are localized about the zones which are vulcanized together, resulting in premature deterioration at this point and the present invention has been devised to obviate this inher- ^4,1ent objection.

Referring to the drawing, I have shown the present invention applied for purposes of illustration to a pneumatic mattress construction comprising an inflatable element I formed of superimposed rubber sheets 2 and 3 which are fabricated in the following manner:

Between the sheets 2 and 3 is placed a separating sheet of paper or other suitable mate- _r_ rial 4, which is of smaller dimension than the ^C,J

1,342 having a pair of spaced apart fabric reinforcement discs internally Incorporated therein and diverging therebeyohd in a balanced manner in embodied relation to the said .diverging portions > of said sheets to reinforce the structure against stresses localizing in said zones.

4. In an inflatable rubber device having juxtaposed sheets converging to vulcanized connections In tufting zones, said tufting zones only 10 having spaced apart discs of reinforcing fabric internally incorporated therein and bonded therewith, the edge portions of such spaced discs diverging and extending into said respective juxtaposed sheets and terminating marginally of the tufting zone.

5. In an inflatable rubber device, juxtaposed sheets vulcanized together at a plurality of zones in such manner as to diverge from said zones forming a multiplicity of air cells, and strata 20 of reinforcing fabric incorporated locally in said connected zones and extending therebeyond in diverging paths in embodied relation to said diverging portions of the sheets, the divergent wall portions of said sheets each being of pro25 nounced but gradually increased thickness as they approach the zones of vulcanized connection and said, strata Of reinforcing fabric terminating marginally within the thickened wall portions adjacent the zones of vulcanization leav30 ing the non-thickened wall portions of the air cells free to normally expand on inflation of the device.

JOHN H. JOHNSON.

2,2 to be construed as limited in this regard but broadly resides in the co-operative incorporation of a flexible reinforcing agent where strains originate between two wall portions of an inflatable device subjected to separating stresses.

In Figure 4 the locally reinforced zone is shown perforated at β' for the passage of tufting cords therethrough, such as when the pneumatic element is provided with a felted covering I'.