Air compressor

Claim 2

In a compressor, a cylinder defining a compression chamber in its interior, inlet means communicating with said comrpession chamber for admitting into the latter gas to be compressed therein, outlet means communicating with said comrpession chamber for discharging compressed gas therefrom, piston means situated in said cylinder for reciprocation therein along suction strokes during which gas enters into said comprssion chamber through said inlet means and compression strokes during which gas discharges from said compression chamber through said outlet means, said piston means being made substantially entirely of a plastic material and defining with an inner surface of said cylinder a gap surrounding said piston means and remaining at all times substantially dry and free of lubrication, a piston rod fixed to and projecting from said piston means, and drive means operatively connected with said piston rod for reciprocating the latter an said piston means therewith in said cylinder along said strokes, said piston means having a head end sitant from said piston rod and forming the working end of said piston means, and blade means of a material substantially harder than said piston means carried by the latter at said head end thereof for acting on the gas to promote a sealing effect at said gap, said blade means being made of metal and being in the form of a cylindrical member carried by said piston means at the head end thereof at theouter periphery of said piston means, said piston means being formed at its head end with an annular groove and with a central boss surrounded by said annular groove so that the latter together with said blade means promote the sealing effect.

Claim 3

In a compressor, a cylinder of predetermined bore diameter defining a compression chamber in its interior, inlet means communicating with said compression chamber for admitting into the latter gas to be compressed therein, outlet means communicating with said compression chamber for discharging compressed gas therefrom, piston means situated in said cylinder for reciprocation therein along suction strokes during which gas enters into said compression chamber through said inlet means and compression strokes during which gas discharges from said compression chamber through said outlet means, said strokes each having a length greater than said cylinder bore diameter, said piston means being made substantially entirely of a plastic material, having a smooth exterior side surface of constant diameter extending between opposed ends of said piston means and defining with an inner surface of said cylinder a gap surrounding said piston means and remaining at all times substantially dry and free of lubrication, a piston rod fixed to and projecting from said piston means, and drive means operatively connected with said piston rod for reciprocating the latter and said piston means therewith in said cylinder along said strokes at a speed of at least 1,500 strokes per minute, said inlet means including an annular wall portion of said cylinder formed with permanently open, uninterrupted inlet openings passing therethrough and distributed about the axis of the cylinder, said inlet openings being tapered and forming inlet nozzles and said inlet openings respectively having axes inclined to the axis of said cylinder.

Claim 4

In a compressor, a cylinder of predetermined bore diameter defining a compression chamber in its interior, inlet means communicating with said compression chamber for admitting into the latter gas to be compressed therein, outlet means communicating with said compression chamber for discharging compressed gas therefrom, piston means situated in said cylinder for reciprocation therein along suction strokes during which gas enters into said compression chamber through said inlet means and compression strokes during which gas discharges from said compression chamber through said outlet means, said strokes each having a length greater than said cylinder bore diameter, said piston means being made substantially entirely of a plastic material, having a smooth exterior side surface of constant diameter extending between opposed ends of said piston means and defining with an inner surface of said cylinder a gap surrounding said piston means and remaining at all times substantially dry and free of lubrication, a piston rod fixed to and projecting from said piston means, and drive means operatively connected with said piston rod for reciprocating the latter and said piston means therewith in said cylinder along said strokes at a speed of at least 1,500 strokes per minute, said inlet means including an annular wall portion of said cylinder formed with permanently open, uninterrupted inlet openings passing therethrough and distributed about the axis of the cylinder, said inlet openings being tapered and forming inlet nozzles and said inlet openings respectively having axes inclined to the axis of said cylinder.

Claim 5

In a compressor, a cylinder of predetermined bore diameter defining a compression chamber in its interior, inlet means communicating with said compression chamber for admitting into the latter gas to be compressed therein, outlet means communicating with said compression chamber for discharging compressed gas therefrom, piston means situated in said cylinder for reciprocation therein along suction strokes during which gas enters into said compression chamBer through said inlet means and compression strokes during which gas discharges from said compression chamber through said outlet means, said strokes each having a length treater than said cylinder bore diameter, said piston means being made substantially entirely of a plastic material, having a smooth exterior side surface of constant diameter extending between opposed ends of said piston means and defining with an inner surface of said cylinder a gap surrounding said piston means and remaining at all times substantially dry and free of lubrication, a piston rod fixed to and projecting from said piston means, and drive means operatively connected with said piston rod for reciprocating the latter and said piston means therewith in said cylinder along said strokes at a speed of at least 1500 strokes per minute, said piston means being formed at its head end with an annular groove and with a central boss surrounded by said annular groove.

Claim 6

In a compressor, a cylinder of predetermined bore diameter defining a compression chamber in its interior, inlet means communicating with said compression chamber for admitting into the latter gas to be compressed therein, outlet means communicating with said compression chamber for discharging compressed gas therefrom, piston means situated in said cylinder for reciprocation therein along suction strokes during which gas enters into said compression chamBer through said inlet means and compression strokes during which gas discharges from said compression chamber through said outlet means, said strokes each having a length treater than said cylinder bore diameter, said piston means being made substantially entirely of a plastic material, having a smooth exterior side surface of constant diameter extending between opposed ends of said piston means and defining with an inner surface of said cylinder a gap surrounding said piston means and remaining at all times substantially dry and free of lubrication, a piston rod fixed to and projecting from said piston means, and drive means operatively connected with said piston rod for reciprocating the latter and said piston means therewith in said cylinder along said strokes at a speed of at least 1500 strokes per minute, said piston means being formed at its head end with an annular groove and with a central boss surrounded by said annular groove.

Claim 7

In a compressor, a cylinder defining a compression chamber in its interior, inlet means communicating with said compression chamber for admitting into the latter gas to be compressed therein, outlet means communicating with said compression chamber for discharging compressed gas therefrom, piston means situated in said cylinder for reciprocation therein along suction strokes during which gas enters into said compression chamber through said inlet means and compression strokes during which gas discharges from said compression chamber through said outlet means, said piston means being made substantially entirely of a plastic material and defining with an inner surface of said cylinder a gap surrounding said piston means and remaining at all times substantially dry and free of lubrication, a piston rod fixed to and projecting from said piston means, and drive means operatively connected with said piston rod for reciprocating the latter and said piston means therewith in said cylinder along said strokes, said inlet means including an annular wall portion of said cylinder formed with inlet openings passing therethrough and distributed about the axis of the cylinder, said inlet openings being tapered and forming inlet nozzles and said inlet openings respectively having axes inclined to the axis of said cylinder, said cylinder being also formed along a second annular wall portion thereof, spaced axially from said inlet openings in the direction in which said piston means moves during a compression stroke, with a plurality of bores passing through the cylinder and providing balancing gas for stabilizing the movement of said piston means, said bores also respectively having axes inclined to the cylinder axis, and the axes of said bores bbeing inclined with respect to the axes of said inlet openings at an angle which enables gas flowing through said inlet openings to retard leakage out of said cylinders through said bores.

Claim 8

In a compressor, a cylinder defining a compression chamber in its interior, inlet means communicating with said compression chamber for admitting into the latter gas to be compressed therein, outlet means communicating with said compression chamber for discharging compressed gas therefrom, piston means situated in said cylinder for reciprocation therein along suction strokes during which gas enters into said compression chamber through said inlet means and compression strokes during which gas discharges from said compression chamber through said outlet means, said piston means being made substantially entirely of a plastic material and defining with an inner surface of said cylinder a gap surrounding said piston means and remaining at all times substantially dry and free of lubrication, a piston rod fixed to and projecting from said piston means, and drive means operatively connected with said piston rod for reciprocating the latter and said piston means therewith in said cylinder along said strokes, said inlet means including an annular wall portion of said cylinder formed with inlet openings passing therethrough and distributed about the axis of the cylinder, said inlet openings being tapered and forming inlet nozzles and said inlet openings respectively having axes inclined to the axis of said cylinder, said cylinder being also formed along a second annular wall portion thereof, spaced axially from said inlet openings in the direction in which said piston means moves during a compression stroke, with a plurality of bores passing through the cylinder and providing balancing gas for stabilizing the movement of said piston means, said bores also respectively having axes inclined to the cylinder axis, and the axes of said bores bbeing inclined with respect to the axes of said inlet openings at an angle which enables gas flowing through said inlet openings to retard leakage out of said cylinders through said bores.

Claim 9

The combination of claim 4 and wherein a substantially bell-shaped housing is fixed to and surrounds said cylinder at said annular portions thereof so that said bores and openings are surrounded by said bell shaped housing, and a filter situated between said housing and cylinder for filtering gas entering into said bell-shaped housing to reach said bores and openings.

Claim 10

In a compressor, a cylinder of predetermined bore diameter defining a compression chamber in its interior, inlet means communicating with said compression chamber for admitting into the latter gas to be compressed therein, outlet means communicating with said comprssion chamber for discharging compressed gas therefrom, piston means situated in said cylinder for reciprocation therein along suction strokes during which gas enters into said compression chamber through said inlet means and compression strokes during which gas discharges from said compression chamber through said outlet means, said strokes each having a length greater than said cylinder bore diameter, said piston means being made substantially entirely of a plstic material, haviNg a smooth exterior side surface of constant diameter extending between opposed ends of said piston means and defining with an inner surface of said cylinder a gap surrounding said piston means and remaining at all times substantially dry and free of lubrication, balacing means for stabilizing the movement of said piston means in said gap spaced from said inner surface of said cylinder, said balancing means being axially spaced from said inlet means in the compression direction in which said piston means moves during a compression stroke, and said balancing means being constituted by a circumferential wall portion of said cylinder means which has an inner surface defining part of said gap and an outer surface communicating with the surrounding atmosphere, said wall portion being formed with a plurality of bores circumferentially distributed about the axis of said cylinder means and each incliend to said axis with each bore having inner and outer ends respectively at said inner and outer surfaces of said wall portion, and said inner end of each bore being displaced from its outer end in said compression direction, a piston rod fixed to and projecting from said piston means, and drive means operatively connected with said piston rod for reciprocating the latter and said piston means therewith in said cylinder along said strokes at a speed of at least 1500 strokes per minute.

Claim 11

In a compressor, a cylinder of predetermined bore diameter defining a compression chamber in its interior, inlet means communicating with said compression chamber for admitting into the latter gas to be compressed therein, outlet means communicating with said comprssion chamber for discharging compressed gas therefrom, piston means situated in said cylinder for reciprocation therein along suction strokes during which gas enters into said compression chamber through said inlet means and compression strokes during which gas discharges from said compression chamber through said outlet means, said strokes each having a length greater than said cylinder bore diameter, said piston means being made substantially entirely of a plstic material, haviNg a smooth exterior side surface of constant diameter extending between opposed ends of said piston means and defining with an inner surface of said cylinder a gap surrounding said piston means and remaining at all times substantially dry and free of lubrication, balacing means for stabilizing the movement of said piston means in said gap spaced from said inner surface of said cylinder, said balancing means being axially spaced from said inlet means in the compression direction in which said piston means moves during a compression stroke, and said balancing means being constituted by a circumferential wall portion of said cylinder means which has an inner surface defining part of said gap and an outer surface communicating with the surrounding atmosphere, said wall portion being formed with a plurality of bores circumferentially distributed about the axis of said cylinder means and each incliend to said axis with each bore having inner and outer ends respectively at said inner and outer surfaces of said wall portion, and said inner end of each bore being displaced from its outer end in said compression direction, a piston rod fixed to and projecting from said piston means, and drive means operatively connected with said piston rod for reciprocating the latter and said piston means therewith in said cylinder along said strokes at a speed of at least 1500 strokes per minute.

Claim 12

The combination of claim 6 and wherein said cylinder has the form of a seamless drawn steel pipe.

Claim 13

The combination of claim 6 and wherein said piston means is made of a material selected from the group consisting of polyethylene, polypropylene, polybutene, polytetrafluoroethylene, polyamide, polyoxymethaline, and polycarbonate.

Claim 14

The combination of claim 6 and wherein said piston means is operated at a speed of approximately 3,000-6,000 strokes per minute.

Claim 15

The combination of claim 6 and wherein a housing encloses said drive means and has a wall portion formed with an opening and a filter located in said opening for cleaning air which enters said housing through said opening.

Claim 16

The combination of claim 6 and wherein said piston means has a head end distant from said piston rod and forming the working end of said piston means, and blade means of a material substantially harder than said piston means carried by the latter at said head end thereof for acting on the gas to promote a sealing effect at said gap.

Claim 17

The combination of claim 11 and wherein said blade means is made of metal.

Claim 18

The combination of claim 1 and wherein said piston rod also is made of a plastic material, said piston means and piston rod being in the form of a single body and said piston rod carrying a reinforcing member.

Claim 19

The combination of claim 13 and wherein said reinforcing member is in the form of an elongated tube extending axially of said rod.