Rimless recapping apparatus utilizing balanced air pressures

{
  "publication_number": "US3847695A",
  "country": "US",
  "kind": "A",
  "title": "Rimless recapping apparatus utilizing balanced air pressures",
  "abstract": "Tire recapping apparatus utilizes a hoop, larger in diameter than the casings to be recapped, over which the bent-up edge of a lower elastic membrane is everted, and the bent-down edge of a similar upper membrane is drawn, for sealing. A tire casing with recap strip in place, enveloped between the membranes, contains an inner tube preliminarily inflated to roundness through a hose leading through the upper membrane. the membranes are then evacuated to apply atmospheric pressure against the assembly, supporting the rounded tube between the beads. Thereafter free communication of ambient air is permitted through the hose to the tube; when vulcanized in a pressure chamber the tube pressure rises and falls with the pressure in the chamber, maintaining the shape of the casing undistorted without any air pressure connection from outside the chamber.",
  "claims": [
    "1. For use in a pressurizable chamber for vulcanizing a preformed tread strip to a tire casing containing an unvalved inner tube without any air inlet connection from outside the chamber, evacuable membrane apparatus comprising enveloping membrane means having upper and lower portions terminating in outer margins at which the membrane means is adapted to be sealed and hAving central portions which extend opposite each other to enclose the central circular space between the beads of such casing, an air evacuation outlet extending through said membrane means and having outwardly thereof check valve means to maintain vacuum between the membranes, and inner tube pressure-balancing means including an inflation inlet extending through said membrane means and having outwardly thereof an inlet connection and communicating through said membrane means to a pressure hose extending to an inner end coupling connectable to such inner tube, whereby, after the inflated rounding of such inner tube and subsequent evacuation of such central space, to provide pressure within such inner tube balancing increases and decreases of pressure within such chamber.",
    "2. The apparatus as defined in claim 1, wherein the inflation inlet and pressure hose are unvalved, whereby such balancing pressure is maintained substantially without lagging despite increases and decreases in pressure within the vulcanizing chamber, thereby maintaining unaltered the conformation of the tire casing.",
    "3. The apparatus as defined in claim 1, wherein the enveloping membrane means comprises an elastic lower membrane having an upward-extending margin and elastic upper membrane having a downward-extending margin, in combination with a rigid hoop having a diameter larger than such casing and larger than the marginal edges of said elastic membranes, whereby the lower membrane may be placed within such rim and its margin everted elastically thereover, the casing to be recapped with its tread strip thereon may be placed within the hoop on the lower membrane, and the upper membrane may be positioned thereover and its margin drawn elastically over that of the lower membrane margin outwardly of such hoop.",
    "4. The apparatus as defined in claim 3, together with means to seal the elastic membrane margins on the outer side of said hoop.",
    "5. The apparatus as defined in claim 4, wherein the means to seal comprises a sealing tape adhered around the periphery of the margin of the everted lower membrane and sealing the margin of the upper membrane thereto.",
    "6. The apparatus as defined in claim 4, wherein the means to seal comprises tension means drawn about the hoop externally of said membrane margins, whereby to bind them together.",
    "7. The method of recapping a tire casing without using a rim, comprising the old steps of removing the tread from the outer periphery of the casing and applying thereto a pressure-curable adherent and a pre-formed tread strip thereover in place for recapping, together with the steps of positioning an inflatable inner tube within the casing without support by any inner rim, positioning the casing, with the tube therein, between enveloping membrane means covering the tread strip, side walls and beads of the casing and the circular areas inwardly thereof, making a pressure connection from outwardly of said membrane means to the interior of said inner tube and inflating it to roundness, sealing the membrane means outwardly of the tread strip, evacuating the membrane means, whereby pressure external thereto will press the circular central areas of the membrane means together and supportively against the radially inner surface of the inner tube between the beads of the casing, and then, while maintaining the membrane means evacuated, and while permitting free communication through such pressure connection of air pressure between the inner tube and the atmosphere external to said membrane means, placing the assembly in a pressure chamber, increasing the pressure therein, curing the adherent means, reducing the pressure within the pressure chamber, and removing the cured assembly, whereby as the pressure is increased and decreased within the pressure chamber, balancing pressures will be maintained within the inner tube without connection to any source of pressure external to the prEssure chamber.",
    "8. The method as defined in claim 7, wherein the curing process involves vulcanization, together with the step of maintaining a vacuum connection from the evacuated membranes to the exterior of the pressure chamber during such vulcanization, whereby to remove gases generated on curing by vulcanization and to remedy any defective sealing of the membrane means."
  ],
  "cpc": [
    "B29D 30/542",
    "B29D 2030/582"
  ],
  "assignees": [
    "GROSS J"
  ],
  "filing_date": "1973-06-28",
  "publication_date": "1974-11-12",
  "grant_date": "1974-11-12",
  "priority_date": "1973-06-28",
  "application_number": "US-37467573-A",
  "family_id": "23477761",
  "citations": [
    "US3236709A",
    "US3325326A",
    "US3729358A",
    "US3730801A",
    "US3743564A",
    "US3745084A",
    "US3769121A"
  ]
}