US2605044A - Air compressor - Google Patents

Description

R. H; HILL AIR COMPRESSOR July 29, 1952 2 SHEETS-'SHW- Filed Dec. 22, 1945 y w n lINVENTOR.

L., f. L M E July 29,v 1952 R. H. H|| 2,605,044

AIR COMPRESSOR Filed Dec. 22, 1945 2 Sl-{EETS-SHEET 2 I N V EN TOR. 190.955 71K .//g L,

Patented July 29, 1952 UNITED. STATES xeri;1\.ifr f QFFIC Robert H. Hin. Fcri Wa f 'rpkiieim .oii'rank and y J Wayne, Ind.. a corporation of Indiana g Aiiiiieiincnnember-22, i945, scriaio. 636,864

" Y rioiaims. (o1. 23o-472V This invention relatesV to a positive displacement air compressor. K l K' v The object of the invention is to produce .a simple, compact air: compressor Whichwill oper'- ate quietly and Yeiiiciently'r `at a relatively high compressor speed lto deliver Vair with low pulsation, which compressor may be mounted Yon and direct connected to a Standard electric motor, to form a readily portable unit.

4 In'an illustrative embodiment `of myinvention,

a compressor crank Y'case 'is mountedv directly on the end of ,a standard electric motor, and the compressor head mounted onthat crank case. A cylinder 'is formed inthe head, and a -pistonris reciprocated therein 4thi'foug'h a rod driven by an eccentric crank-on the shaft of the electric motor. The piston isgenerally T-s'haped'in vertical section;k Vwithy the stern of the T ei'tending upwardly into a guide 'bore iii-'the head-to guide the piston and'perm'itit to be made-substantially skirtless. 1

Intake and discharge passages are formed in the head, communicating with the cylinder through valves in the lcylinder head.- The valve elements. are iformed Aas light-weight disks, carried With their seats and valve Ysprings in unitary assemblies pressed in suitable .bores in thecylinderhead.

The compressor desirably vreceives .air through a screened silencing .and .intake tube; .which is desirably positioned to vform a handle for'transporting the compressor. An inner intake screen is desirably kept'moist-and the crank-*casemaintained under slight vacuum, by venting the crank case through a valvedpassage which'open's to the intake passage outsidesuch -inner screen. The relatively high speed-cf the compressor delivers air with minimum pulsation, but preferably I forman absorptionlc-hamber in the com-Y pressor base, and deliver air therefrom through a tting which also embodies anoverload relief valve and a manual relief and clean-out valve.

While my compressorl Yis designed forA associa;V

tion with an electric motonland is yso shown v in the accompanying drawing,v it may be driven by other sources'of powr,as by substituting.- an internal'` combustion engine .for ythe electric-motor.

The .accompanying ldrawings,y illustrate my in- Vention.' In such drawing's ig.- Vlisan endelevation of Va compressor embodyingl my. invention; Fig..2' is a side elevationof the compressor shown innig.V 1, with 'the' .crank ca'sefhead'; and outlet fitting Shownin section; .Figfis la' horizontal setion thro'ugl'iV the head olftlieA compressor yne, Ind., assigner togy Pump Company, Fort Fig. v3, showing the Valve units; and Fig. .5 is .an

' elevation of the connecting rod and eccentric,

withV the big end o'f the rod shown in section.

The compressor is shown in the drawings as associated with an electric motor Il). The crank case VIl of the compressor is mounted directly on the end of the motorv l0, andthe compressor head l2 is mounted on the crank case Il.

An eccentric I5 is` mounted on the Shaft I6 of the motor i6, convenientlybyakey Il 'locked in the key Way of the shaft IE by'a set screw I8. The big end ofthe connecting "rod 2U is mounted on the eccentric fpreferablyby needle bearings il, and is heid against axial movementby 'counterweight disks .22 attached against -the's'l'des' of' the eccen'tr'icl as bylbolts" 23. The'sniallend ton by a sleeve hearingaiiiia pistcnpint. `Desirabiy, the ypiston pineis locked to the' piston by a cross pin 2.1; y

The piston 4is icrrri'e'ci of a ,carrier ,25 and `a head 30. Ihevcar'er extends upwardly' .to for-in a hollow guide Vrod'Z'slidableinfa central guide borel in the 'head 12. "The pistnY head '13.0 is mounted on the carrier "25, desir'ablylbyllocldng it against a suitable shoulder v'v'ith a lock' nuti which is pinned inlocked position. HThe pistonr head se is relatively shcrtwith its side wall's'cf sufiicieni length to fonte ring band and' some bearing surface .against the @cylinder ."35, but

with substantially no skirt. Vv'Ilieuse of tl'ieguide 28 fully prevents piston vvbble Without the .necessity for any extended skirt .on the piston. This permits the Di'stnafnd 'cylinder'.tobe .Short so that the cylinder can conve''nie'ritly be formed in the head; andreduces the Weightof the Inoving parts to facilitate operationat the relatively high speed `(for a coi'n'pressor)A .of a standard` electric-motorl. Y

An intake .passage-37 lis ioimedj-inV the-head,

and to receive oneendlofan intaketube#3532` The Y passagelis shouldered-so that a lter screen 39 may .be received betweentheshoulder and the u v Desiiably; the screen 39 is formador,tvvohlayersjoiwiremesh,

y with an intervening layero f-.ffelt .An additienal ier-iai.

screen Qn'iay .be .placedin .the openend 4of the tube 33,.andi`f`desired thee3@ may Acontain Silemnngvv material, but I have foundY that'lthe compressor operate ""th remarkablequietness withoutthe neces. A,si-llene.ing @heavier @12de .ebefrl-isrsecured to 1the .motor |!J,. s.by.,a.b`racket 44,' sothattlfie tube may serve .a'handle 6r .transportingthe compressor.

Y'rheiritake passagearieas tcaipair, ci iiiieie,

valves. Each such valve is formed in an annular body 50, shaped to provide a valve seat 5l. A light-weight disk-shaped valve element 52 is associated with the valve seat 5l, and its displacement is desirably limited by a raised central portion Yof a holder 54, which portion may also serve to center a valve spring 53 supported by the holder 54. The valves are formed as units, and are pressed into bores in the top wall of the cylinder 35.

The outlet valves 55, which are similarly pressed in place, are similar in construction to the inlet valves 50-54 and have similar disk valve-elements 56, but may be of slightly smaller size. An outlet passage 51 leads from the outlet valves 55, and is connected to a pipe 58.

The Valve disks 52 and 5B are of light weight and of low inertia. Preferably, they are of spring steel about six to eight thousandths (0.006 to 0.008) of an inch thick, to give adequate lightness with sufiicient strength for long service.

A vent passage 42, drilled in the crank case and head, leads from the crank case to communication with the intake passage just outside the screen 39. A seat for a valve in this vent passage 42 is formed in a chamber 43 in the upper surface of the crank case, and a disk valve 4 is positioned in the valve chamber 43 against the seat when the compressor is assembled. The I head 45 of a screw in the lower surface of the head I2 overlies the valve disk 44 to limit its displacement.

The valved crank-case vent maintains the case under slight vacuum and leads normally escaping oil vapor to the intake, to moisten the filter screen 39. Such oil vapor also supplements the splash system of lubrication, especially when high pressure operation tends to dry the cylinder walls, for under those conditions oil-vapor escape tends to increase, and this is delivered through the intake for top-cylinder lubrication.

The cylinder head is secured to the crankcase, as by stud bolts, in a plane below the cylinder 35. The cylinder 35 and the bore for the piston guide 28 are thus formed in an integral head, for permanent alinement. This arrangement also serves to place the compression space within the integral head, where adequate air cooling may be obtained by a single set of iins carried by the head.

The compressor is carried by a base 68, preferably by mounting the motor I on a suitable bracket 6l on that base 6U. The base 68 is formed to provide an absorbing chamber G5, to which the pipe 58 leading from the outlet passage 51 of the compressor is connected.

The compressed air is delivered from the absorbing chamber 65 through an outlet connection E of a fitting 10, which also houses an overload relief valve and a clean-out and manualrelief valve. The over-load relief valve is formed in a boss 13 on the fitting 10. It has a plunger 12 spring-pressed inwardly to urge its bluntly tapered inner end against a seat formed in the fitting 1G, to normally close a passage 14 which is in open communication with the absorbing chamber 65.

A clean out tube 15 leads from near the bottom wall 64 of the absorbing chamber 65 upwardly through the fitting 10 out of communication with the normal air delivery passage, to a valve 16 which is normally held in closed position by the spring 11. A head on the stem of the Valve 16 may be manually depressed to open the valve 16 4 and release air through the clean-out tube 15 to a relief opening 18. Normal operation of the relief valve 16, as when starting the compressor, will automatically give clean-out action to remove any accumulation of moisture and oil condensation. A 1

My compressor may, be direct connected through the connection 66 to a device requiring compressed air, such for instance as a spray gun, a grease gun, etc.

The design of my compressor, and the low weight of its moving parts, contribute to make it operate quietly and eiiiciently at high speed, as at the standard high speed of the electric motor i0, or even at substantially higher speed. Oil vapor unavoidably escaping from the crank case is carried by the vent-passage to the intake and utilized to moisten the filter and for top lubrication, especially when operation at high pressures tends to reduce normal top-cylinder lubrication.

Air delivery is smooth and prompt, to provide air at high pressure, or in greater quantities at lower pressure, as its use may require.

I claim as my invention:

1. An air-compressor, comprising a motor having a frame and a power shaft, a compressor crank case mounted on said frame, an eccentric crank mounted on said shaft within said crankcase, a compressor head on said crank-case, a cylinder formed in said head, a piston in said cylinder, a piston rod connecting said piston to said eccentric crank, a flat base supporting said motor and compressor, said base having spaced upper and lower walls joined at4 their edges to form a flat absorption chamber substantially coextensive with the base, said discharge passage being connected in open communication with said absorption chamber, and an air delivery fitting on said absorption chamber.

2. An air-compressor, comprising a motor having a frame and a power shaft, a compressor crank case mounted on said frame, an eccentric crank mounted on said shaft within said crankcase, a compressor headv on said crank-case, a cylinderformed in said head, a central guidebore in said head yat the end of said cylinder, a piston in said cylinder having a guide slidably received in said guide-bore, -a piston rod connecting said piston to said eccentric crank, a screen in said intake passage, a vent passage leading from said crank case and discharging to said intake passage outside said screen, and a check valve in said vent passage opening toward said intake passage, said crank case being closed save for said vent passage: I y

3. An air-compressor, comprising a motor, a compressor includinga piston and cylinder, an eccentric crank connected for op-eration at motor speed to reciprocate said piston through short strokes insaidV cylinder, a dat Vbase supporting said motor and compressor, -a flat absorption chamber formed in said base, means connecting vthe discharge from said compressor in open communication with said absorption chamber, and an air delivery fitting on said absorption chamber.

4. An air-compressor, comprising a motor having a frame and a power shaft, a compressor :crank case mounted on said frame, an eccentric crankmounted o n said shaft Within said crankcase, a compressor head on said crank-case and having an intake passage, a cylinder'forrned in Vsaid head, a piston in said cylinder,` a piston rod connecting said piston to said eccentric crank,

a' screen in said intake'passage, a vent passage leading from s-aid crank case and discharging to s-aid intake passage outside said screen, and a check valve in said vent passage opening toward said intake passage, said crank case being closed save for said vent pass-age.

5. An air-compressor, -comprising a crank case and a crank mounted for rotation therein, a compressor head on said crank case, a cylinder formed in said head, a piston connected to the crank for reciprocation in the cylinder, an intake passage formed in said head, a crank-case vent passage in said head extending from said intake passage through the face of the hea-d joint with said crank case, a -connecting vent passage in said crank case, .a valve chamber in said vent passages at said joint, and a check valve `in the valve chamber opening toward said intake passage, said -crank-case being closed save for said valved vent passage.

6. An air-compressor, comprising a crank-case, a shaft mounted `for revolution therein, an eccentric sleeve mounted Ion sai-d shaft, a cylinder supported on said crank-case, a piston therein, a connecting rod having its big end rotatably received on said eccentric sleeve, counterweigh-t disks secured on the ends of said eccentric sleeve and preventing axial displacement of said connecting rod therefrom, said -connecting rod being connected -to reciprocate said piston, and valved 1ntake and disch-arge passages to and from said cylinder.

7. An air compressor, comprising a crank case and a crank mounted for rotation therein, a compressor head on said crank-case and having an intake passage, a cylinder formed in said head, a piston in said cylinder, a piston rod connecting said piston to said eccentric crank, a screen in 6 said intake passage, la vent passage leading from said crank-case and discharging to said intake passage outside said screen, anda check valve in said ven-t passage opening vtoward said intake pas-sage, said crank case being closed save for said vent passage.

ROBERT H HILL.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTSn Number Name Date 527,787 Heath Oct. 23, 1894 893,854 Lock-e et al July 21, 1908 1,137,877 Manly et a1. May 4, 1915 1,187,031 Black et a1 June 13, 1916 1,305,758 Warnock -June 3, 1919 1,376,359 Quigley Apr. 26, 1921 1,555,287 Howe Sept. 29, 1925 1,556,040 Shvely Oct. 6, 1925 1,789,395 `Summers Jan. 20, 1931 1,820,732 Davey Aug. 25, 1931 1,844,416 Bacher et al. Feb. 9, 1932 1,872,805 Peterson Aug. 23, 1932 2,109,718 Bayers Mar. 1, 1938 2,136,098 Browne Nov. 8, 1938 2,136,339 Halleck Nov. 8, 1938 2,155,236 Newell Apr. 18, 1939 2,163,391 Aikman June 20, 1939 2,267,479 Sturm Dec. 23, 1941 2,336,240 Gavin Dec. 7, 1943 FOREIGN PATENTS Number Country Date 869,859 France 1941

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