US2176691A - Fluid compressor - Google Patents

Description

Oct. 17, 1939. R. T. SIMONS I FLUID COMPRESSOR Filed April 9, 1957 .11: I M12 A W/,//////% L alllw m 0 J lia /6222221 fibert 11522120706 Patented Oct. 17, 1939 UNITED STATES PATENT OFFICE FLUI COMPRESSOR Illinois Application April 9, 1937, Serial No. 135,861 9 Claims (91.230-172) This invention relates to compressors and more particularly to machines of this kind for compressing air.

Generally stated, the object of the invention is to provide a novel and improved construction, whereby a comparatively inexpensive but at the same time satisfactory compressor is provided which has certain specific details of construction that tend to increase the general efficiency and desirability of a compressor of this particular character.

To these and other useful ends, the invention consists in matters hereinafter set forth and claimed and shown in the accompanying drawing, in which- Fig. 1 is a vertical section of a compressor having a construction embodying the principles of the invention.

Fig. 2 is a horizontal section on line 2-2 in Fig. 1 of the drawing.

Fig. 3 is a perspective of an oil baflie, on a smaller scale, shown in Fig. 1 of the drawing.

As thus illustrated, the invention. comprises a vertically disposed cylinder section 1, which 5 is provided at its lower end with a flange 2, and at its upper end with a flange 3, together with an enlargement 4 at the bottom thereof. The flange 2 is bolted to the flange 5 of the crank casing 5, which latter is provided with a bearing l for the crank shaft 8, which is driven by the pulley 9 fixed thereon. The said crank casing is partially filled with lubricating oil, and the side of the crank casing is provided with a double louvre H] which permits air to pass through, but

which prevents the oil from splashing out of the casing.

The vertically reciprocating plunger H is connected by a pitman l2 with the crank l3 on the inner end of the previously mentioned crank shaft 8, so that this plunger H is reciprocated up and down to compress air or any other fluid. The lower end of the plunger has a reduced portion forming an annular flange l4, and a metal oil baflle l5 has its lower end provided with a flange l6 that. is suitably held between the flanges 2 and 5, previously mentioned, and the cylindrical portion of this baffle I5 is of such diameter that it telescopes freely within the annular flange it previously mentioned, when the plunger moves downward. Preferably, the flange 14 does not actually contact or rub on the b ame !5, but the two are preferably quite close together. Holes l! are provided in the flange Hi to permit any oil that splashes into the enlargement 4 to run back into the crank casing. In this way, sufiici'ent splash lubrication is provided for the crank axle and its bearings, and for the reciprocating plunger as well, but without danger of flooding the interior of the cylinder and the consequent escape of oil into the portions of the machine 5 above the plunger.

The valve mechanism at the top of the machine comprises a sort of head casting l8, which is practically flat on its top and bottom having its bottom provided with a lateral flange l9 that is 10 bolted flatwise to the flange 3, previously mentioned. A cap 20 is held by a central screw 2| in place on the casting i8, as shown in Fig. 1 of the drawing, with an air filter plate .22 between them. Thus, the air enters. above this 15 filter plate 22, and passes. downwardly into the space immediately above the inlet valve 23, which latter is simply a disk adapted to close upwardly against the integral lower edge of the inlet opening 24, in the head l8, and which opens down- 20 wardly within the spider ring 25, which latter has screw thread mounting to hold it in place, it being observed that the plate 20 is formed at its outer edge toclamp the peripheral portion of the filter plate 22, so that the latter is firmly g5 clamped in place in the top of the cylinder head. The formation of the plate 20 is such as to provide air inlets, as indicated by the arrows, to admit air to the space between the two plates, so that airmay then pass downwardly through 30 the filter plate and into the space immediately above the inlet valve 23, which space thereby forms an air inlet. As shown, the air first passes up through the margin of the plate 22 and thendown through the latter. In addition, it will. be 35 seen that a bushing portion encircles the screw 2!, just under the plate 20, and has its lower end firmly seated on atop portion of the cylinder head, so that When the screw is tightened in the head the plate 20 will be rigidly seated on the 40 said head, with enough pressure on the filter plate 22 to hold the latter in place. The air thus admitted to the cylinder l, above the plunger H, is then compressed by the upward movement of the latter, and forced out through the outlet 45 valve comprising the disk 26, which latter opens. upwardly against the reduced lower end of the screw threaded plug 21, which latter is removable. When the disk 26 moves downward, it engages the integral upper edge of the outlet 50 opening 28 in the machine head I8, whereby the valve 23 opens when the plunger I! moves downward, and the Valve 26 opens when the plunger moves upward, thus alternately drawing air into the machine and forcing it out. A pipe 29 con- 55 nects with the outlet opening 30 in the side of the cylinder head !8, and from this pipe the compressed air may be transmitted to any suitable or desired apparatus. For example, the machine can be used for furnishing compressed air to the spraying apparatus with which paint or similar liquids can be sprayed onto any desired surface.

Thus, the pitman I2 has a bearing at both ends, as shown, and hence the plunger II has vertical sliding reciprocation in the cylinder I, and at the same time the oil baflle means provided by the elements I4 and I tend to minimize the danger of having the lubricatingoil creep upward and enter the air compressing chamber of the machine, as, by the bafile constructionshown and described, the splash lubrication of the inner sides of the cylinder, and the sides-of the plunger, is limited to the minimum necessary for lubricating the reciprocating plunger, and it will be understood that the oil which thus lubricates the plunger serves also to lubricate the wrist-pin connection 3| between the plunger and the upper end of the pitman I2, as indicated in the drawing. The inlet and outlet valves in the machine head are easily accessible, by simply removing the cap 20 and the filter plate 22, and the head I8 can be removed in order to remove the inlet The crank case only has one bearing to lubricate, and preferably the crank has a counterweight 32 to more or less balance the weight on the crank I3, and thus reduce friction of the shaft in its bearing, and to reduce vibration. And

it will also be seen that the double louvre Ii] not only forms a breather for the machine, when the plunger II reciprocates up and down, but also provides an opening through which the crank shaft 8 can be inserted in its bearing I, when the parts of the machine are assembled. Springs can be provided for closing the valves, if desired. As shown, each valve has a seat formed by an integral portion of the section I8 that forms the cylinder head.

Preferably, as shown in Fig. 1 of the drawing, the cylindrical and downwardly extending flange M is spaced a distance from the interior surface of the cylinder I, so that the area of contact between the cylinder and the sides of the plunger is not increased by the provision of this depending flange on the lower end of the plunger. This not only reduces friction, but it also tends to insure better or cleaner drainage of the oil from the cylinder and plunger back into the crank case, and thus tends to contribute to the prevention of excess oil in the cylinder, for while the plunger and cylinder are dependent upon the splash systerm, for adequate lubrication thereof, it is not desirable to run the risk of flooding the cylinder, for the reasons previously explained.

Thus it will be seen that the flange I4 is entirely additional to the normal size and height of the piston or plunger, and is entirely frictionless, and it will also be seen that the stationary cylindrical bafiie I5 is entirely frictionless, so that the said flange and bafile do not add any friction to the machine, and with this construction boththe inner and outer surfaces of the flange I4 are free to drain the oil downwardly, so that it will drip freely from the lower edge of the flange into the space between the baffle and the sides of the cyl-| inder, in order that it may then return through the opening H to the interior of the crank case.

Obviously, the proportions are such that the splash occurs, or may occur, after the lower end of the flange I4 has telescoped a distance over the ai'racoi upper end of the baflie- I5, the initial telescoping beginning before the splash occurs, so that the cylinder is not flooded.

It is of the essence of the invention, therefore, that the cylindrical baffle I5 is to permit oil to enter the cylinder, from the splash chamber below, and that it is not equipped with any provision that would in any way interfere with this function of lubricating the plunger inthe cylinder. The lower edge of the flange I4 and the upper edge of the bafiie I5 co-operate, of course, as explained, to prevent flooding of the walls of the "cylinder with oil from the crank case, but

there is essentially nothing in the formation of the bafile'itselffor in the interior thereof, to prevent the'free passage of oil upwardly into the cylinder. To that function, therefore, is added the other function of permitting air to pass up into the cylinder, for breathing purposes, for there are no other provisions for this breathing function, and for that purpose air passes upwardly through the body of the baflie I5, and also upwardly through the holes ll, so that this baiiie in one way or another provides the only means for admitting and discharging air below the plunger, to insure the necessary breathing action of the compressor.

And, as clearly shown and described, this cylinder I5 has the further and additional function of permitting practically free and unrestrained passage of the splash oil upwardly into the cylinder I, as the cylinder is made of sufiicient diameter for that purpose, and such oil is controlled by the flange I4 to prevent flooding of the cylinder, and the oil then drains downwardly from the chamber 4 through the opening I I and into the crank case 6 in which the oil is contained, so that the cylinder I5 is a conduit for the free passage of both splash oil and breathing air for the interior of the cylinder.

What I claim as my invention is:

1. In a fluid compressor, a cylinder section, a plunger reciprocating therein, and a valve section removably attached to the cylinder, forming a hollow head therefor and having an inlet and an outlet valve therein, with integral portions of the section forming a seat for each valve, the head being practically flat on its top and bottom and having an inlet opening in its top, removable screw threaded means for limiting the opening action of each valve, screwed into the top of said head for said outlet valve, and into the bottom of the head for the inlet valve, so that the screw threaded means for the outlet Valve is removable upwardly from the head, while that for the inlet valve is removable downwardly therefrom, and axially fastened clamping means resting flatwise on the top of the head and serving to admit air to said inlet opening, said clamping means being readily removable from the top of the head, while the latter remains attached to the cylinder.

2. A structure as specified in claim 1, said clamping means comprising a filter plate over the said inlet for said cylinder head, and a cap plate for removably holding the filter plate in place.

3. A structure as specified in claim 1, said clamping means comprising a filter plate over the said inlet for said cylinder head, and a cap: plate for removably holding the filter plate in place, having a single center screw for holding the cap plate in place, with lower edges of the cap plate clamping the annular edge of the filter plate, and with an outlet at the side of said valved cylinder head section in communication with said outlet valve.

4. A structure as specified in claim 1, said screw threaded means comprising a screw plug having its head covered by said clamping means, so that by removing this plug a valve can then be removed, with the lower end of said plug formed with a reduced end portion to engage the top of the valve, for limiting the upward opening movement of the outlet valve, and also comprising a screw threaded spider for limiting the opening movement of the inlet valve, said head having a lateral outlet leading from between the plug and the valve, sothat said outlet is independent of said clamping means.

5. In an air compressor, a cylinder having a reciprocating plunger therein, a flat plate forming a cylinder head for closing the upper end of the cylinder, inlet and outlet valves in said head, a lateral air outlet leading through the side of said head from said outlet valve, means integral with the head to form the closing seat of each valve, a plug screwed into the top of the cylinder head, above the outlet valve, forming a stop to limit the opening movement of this valve, and whereby the latter can be removed by first removing the plug, so that said outlet extends from the space between the upper side of the valve and the lower end of said plug, means screwed into the under side of said cylinder head to retain the inlet valve in place, said head having an air inlet in its upper side, above said inlet valve, a filter plate disposed flatwise upon the top of said cylinder head, covering said air inlet and the top of said plug, said inlet valve preventing air from being expelled through said filter plate, but permitting air to be drawn in through the latter, a clamping plate formed to engage the periphery of said filter plate, and a central screw extending downwardly through both plates and into said cylinder head, at one side of said plug, thereby removably holding the filter and clamping plates on the top of the cylinder head.

6. A structure as specified in claim 5, said filter plate and clamping plate being spaced apart to permit air to enter between them at their outer edges and pass down through the filter plate, and the clamping plate being seated on top portions of the cylinder head.

7. In a machine with a cylinder having imperforate sides and a reciprocating piston or plunger therein, fluid inlet and outlet valves for the top of the cylinder, through which valves all fluid that enters and escapes above the piston or plunger must pass, a crank case having a breather opening in the wall thereof, to allow air to enter and escape during the reciprocation of the piston or plunger, the open bottom of the cylinder being mounted upon the open top of said casing, so that when the piston or plunger moves upward air enters through the breather, and whereby air escapes through said breather when the piston or plunger moves downward, a vertical cylindrical flange depending from the bottom of said piston or plunger, a vertical cylindrical baflle open at top and bottom and fixed at its lower end, spaced from the sides of the cylinder and providing a vertical conduit for the free flow of air from and to said breather, into and out of the cylinder, and for the free admission of splash oil from inside said casing, the lower edge of said flange and the upper edge of said baffle co-operating to regulate or restrict the amount of oil entering the cylinder from said crank case, to lubricate the piston or plunger in the cylinder, so that all air that enters and escapes from the cylinder below the piston or plunger must pass through the open bottom of said cylinder, and whereby all oil that enters the cylinder for lubrication must also pass upwardly through said open bottom, together with a crank in said casing, and a link having free play in said baffle to connect the crank with the piston or plunger, said flange telescoping over the bafile when the piston or plunger moves downward, for preventing excess of oil in the cylinder and thereby preventing oil from reaching the space above said piston or plunger, while precluding any pocketing of air below the latter.

8. A structure as specified in claim 7, said vertical bafile having a flange at its lower end formed with openings to drain the oil back into said casing, and through which some air may enter and escape from the cylinder.

9. In a reciprocating machine having an upright cylinder and a piston or plunger reciprocating vertically therein, a frictionless flange forming an extension on the bottom of the piston or plunger, a stationary cylindrical frictionless bafiie disposed in position to telescope within the said flange, when the piston or plunger moves downward, preventing any friction whatever between the baffleand any other portion of the machine, and preventing any friction between the flange and any other portion of the machine, together with a crank case having splash means for splashing oil upwardly through said b aille, into the cylinder, the lower edge of said flange and the upper edge of said baffle co-operating to regulate or restrict the amount of oil entering the cylinder from said crank case, so that the battle serves as an oil conduit for admitting oil to the cylinder to lubricate the said piston or plunger therein, and said flange and baffle serving to prevent excess oil in the cylinder.

ROBERT T. snvrons/

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