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PNEUMATIC DOOR CLOSER

  • US 3,593,367 A
  • Filed: 08/15/1969
  • Issued: 07/20/1971
  • Est. Priority Date: 08/15/1969
  • Status: Expired due to Term
First Claim
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1. A pneumatic door closer comprising:

  • a. an elongated casing having an inner cylindrical wall surface, a closure member at one end, and an axial opening at its other end;

    b. a plunger rod extending axially through said axial opening for movements axially of said casing and having inner and outer ends respectively within and axially outwardly of said casing;

    c. means on said plunger rod outer end and said closure member for connection one to a doorframe and the other to a door hingedly mounted in the doorframe;

    d. piston means on the inner end of said plunger rod comprising;

    1. body structure including a disclike washer element having a flat radial wall portion and air passage means extending in a direction axially therethrough, and a generally cup-shaped valve seat element having a conical wall portion diverging radially outwardly with respect to said flat radial wall portion and defining therewith a radially outwardly opening annular channel, the body structure having radially outer marginal portions inwardly spaced from said cylindrical wall surface, said washer element being disposed between said valve seat element and said closure member;

    2. a sealinG ring in said channel concentric with and in close fitting sliding engagement with said inner cylindrical wall surface and movable toward and away from sealing engagement with said conical wall portion;

    3. and a porous lubricating ring in said channel in closely fitting sliding engagement with said cylindrical wall surface axially adjacent said sealing ring and positioned to engage said flat radial wall portion;

    4. said channel having an axial dimension greater than the combined axial dimension of said sealing and lubricating rings to permit limited axial movement of said body structure relative to said rings e. and yielding means in said casing urging said piston means and plunger rod in a door-closing direction toward said closure member;

    f. said valve element being formed to provide an axial hollow boss defining a recess for reception of the inner end of valve seat plunger rod, said inner end of the plunger rod and said washer being welded to said boss. 2. The door closer defined in claim 1 in which said washer element includes axially projecting flange means telescopically received over said boss to axially align said washer element with said valve seat element.

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