US2053593A - Air compressor - Google Patents

Description

p s, 1936 v A. 2.5 m 2,053,593

AIR COMPRESSOR Filed Oct. 2, 1953 3 Sheets-Sheet 1 1/7 I INVENTORS ATTORNEY Sept. 8, 1936.

A. ZISKA r AL AIR COMPRESSOR 1933 3 Sheets-Sheet 3 Filed OCt. 2

I lllllllllllllllllllll Patented Sept. 8, 1936 PATEEEN'T, OFFICE v AIR COMPRESSOR Adam 'Ziska, Wauwatosa, and Conrad A. :Biebler,

Shorewood, Wis.

Application October 2, 1933, SeriaINo. 691,812 16-Claims. (o1. zen-58) contacts with the air either 'before, during, or

aitercompression, in which-means are'provided in which the construction is'such that seli-lubrieating material forms 'oneof-the relatively-sliding surfacesorrelatively-movable parts of the air compressor, so that the air is drawn in, compressed, and stored without contact with 'any oil whatsoever.

' Incertain classes-of work, forexamplesupplying compressed air or other gas in dispensing beverages, such, for example, as been it is highly desirable, though heretofore unaccomplished, to supply compressed air-absolutely free from any'oil or oil fumes or any smell of oil. Thisrequirement alsoexists in other 'types-ofcompressed-air work. Although this is-onlyone instance-of the need -of-compressed air free from oil fumes or oil, it is'obvious that there are numerous other conditions under which it is required, such for 'instance, as dental work, spraying, and'soforth.

Further objects are to provide a 'unitarystructure in which a motor and 'a compressor are formed as a unit and may be used "as such, if desired, but in which such composite unit formed of the motor and compressor "form, in effect, the relatively heavy base of the 'uriitary-structm'e, the upper portion of thestructure consistingof a storage tank mounted directly upon the compressor and surmounted by automatic control and indicating devices controlling the operation of the motor in accordance with the air pressure, and

" alsocontrolling the pressure of the discharged'air by means of an automatic pressure reduction valve, suitable gauges being provided and the entire upper structure being covered by a closure cap merginginto the outline-of'theta'nk.

Further objects are to provide a unitary construction in which the relatively heavy base formed of the electric motor and the compressor unit merge into the outline of the tank, such, for example, as a cylindrical tan'k, so that the entire structure has no exposed running parts, "but instead in which the unitary construction provides a substantially cylindrical unit which is complete in itself and which requires no additional fittings whatsoever.

of wiring with the motor forming a portionjof the base of the apparatua'such'wiring being carried in permanently mounted rcondu'it secured to the tank, and the *base and the'upper portion having interengaging'electrical connectors so that when the tank is removed, theconnection is automatically brokenwithouthaving 'anyloose wires whatsoever, and when the tank is "replaced, the connection isaga'in made, all without the need of disconnecting or reconnecting anywireswhat'soever;

Further objects are to provide a unitary air compressor construction inwhich the motor and air compressor constitute arelatively heavy 'base for the device, the lighter 'taiik structure being mounted thereon andfinithi's manner avoiding noise and vibration, the air'compres'soribeing also so constructed that a substantially perfect balancing of the moving parts is obtained, thereby additionally avoiding vibration and noise. Further objects are to provide a unitary'air compressor construction in which the air coni-' pressor unit is preferably annular, though ob 0 viously it maytake other shapes, and is provided with a plurality] of "radial cylinders and with a, floating centrally located crank shaitfor driving the pistons of the cylinders, such floating shaft being slidably coupled to the driving shaft of the lubricating materialjin'which the articulatedends o'fthe connecting rods are also hushed with this material, and :in which a driving head issup portedflthrou'gh the medium ofb'a'll bearings from the crank so that an oilless construction results, the 'cornpressofbeing divided off from the motor by a transverse 'partitiorrformed preferably .in'tegrally with the compressor" unit,su'ita ble ventilation for the motor being: provided by openings in the lower andupperportion of the structure that forms the housing for the motor, the upper por-' tion oi the air compressor unit constituting an intake t'cha'mber, the unit itself bein'gpreferably provided with an annular intake chamber equipped with a removable ring of filtering mai- I ter'ral. I i V r l f Further objects are to provide an air compressor'in' which removable valve guiding" means close the outer openingsthro'ug'h thebody portion 7 of the 'c'ompressor'in alignment with the 'radial'f cylinders and, inone' form'o'fthe' invention. in '55 which the valve itself directly seats upon the sleeve lining the cylinder, the construction pro- 'viding an annular chamber circumscribing the cylinders and into which the cylinders discharge past the valves.

Further objects are to provide an air compressor which may be formed in any size, such, for example, as a small unit suitable for use in taverns, or in sand blasting, or in other work where a relatively small compressor is desired, although obviously as the description of the invention proceeds, it will be apparent that the compressor can be made in any size desired.

Further objects are to provide an air compressor in which novel means are used to secure the pins for the connecting rods to the driving head carried by the crank in a manner to provide an extremely compact and secure construction, and in which the construction lends itself to the looking of one piston rod rigidly to the driving head carried by the crank so that this piston rod forms a master rod for suitably holding the driving head, the other piston rods being articulated at each end.

Embodiments of the invention are shown in the accompanying drawings, in which:

Figure 1 is an elevation of the unitary air compressor, with parts broken away.

Figure 2 is an enlarged vertical sectional view on the line 2-2 of Figure 1, such view being broken away. i

Figure 3 is a plan view on the line 33 of Figure 2, with parts broken away.

Figure 4 is a view of the top of the apparatus with the cap removed.

' an air compressor unit or body portion 2, an

unit.

electric motor unit 3, a finishing support or base portion 4, and a cover 5 surmounting the storage tank, the compressor and motor, together with the finishing base portion 4, constituting,

in effect, the relatively heavy base of the apparatus. The air compressor unit is joined to the tank by means of a short pipe 6 provided with detachable fittings l and 8. It is also preferable to provide a drain cock 9 for the air compressor Referring particularly to Figures 1, 2 and 3, it will. be seen that the air compressor unit comprises a body portion 2, as' previously described, which is equipped with a downwardly extending annular flange I0 seating upon the stator ll of the motor, the motor stator in turn resting upon the finishing. base or support 4. The motor armature I2 is carried by the driving shaft l3 and a ball bearing or step bearing indicated generally at 4 is provided for supporting the lower end of the motor shaft.

In purchasing the motor for this apparatus, it is obvious that the end plates are not needed as the finishing base and the compressor together take the place of the end plates of the motor.

The three parts may be locked together in any suitable way, as -by means of the tie bolts |5, such bolts being threaded into lugs I6 carried by the compressor unit and being provided with nuts I! at their lower ends.

Referring in greaterv detail to the air compressor unit, it will be seen that the body portion is provided with a plurality of radial cylinders l8. Each of these cvlinders is equipped with a piston l9. The pistons are driven from a crank 20 which is counterweighted as indicated and which is carried by a floating crank shaft 2|. This crank shaft is carried by a ball bearing indicated generally at 22 in Figure 2, and has a sliding keyed fit with the upper end of the motor shaft. It is to be noted that the inner race of the ball bearing 22 is locked to the shaft 2| and that the outer race is locked by means of a plate 23 to the transverse partition wall 24 of the compressor structure. Thus this bearing is a floating or semifloating bearing and is so made that the shaft may be directly slipped over the driving shaft of the motor in assembling or disassembling the parts.

The crank 20, of course, may be replaced by an eccentric if desired, and it is to be understood that the term crank hereinafter used is intended to be interpreted in its broadest aspect.

Thiscrank 20 is provided with a shouldered portion 25 upon which the inner race of the lower ball bearing 26 rests. It is provided with a threaded reduced upper portion 21 which receives the nut 28 and washer 29 which holds the inner race of the upper bearing 30 in place. The driving head 3| is provided with an intermediate small flange which spaces the outer races apart and thus the driving head 3| is locked against displacement either in an up or down direction and yet is supported by ball bearings from the crank.

The driving head 3| is provided with upper and lower flanges 32 and 33 between which the ends of the connecting rods 34 are received. All of these connecting rods are articulated at both ends at the points where they are connected to the driving head and the cylinders, except one. This connecting rod is shown in Figure 2. It is provided with an enlarged inner head 35 which is curved to fit the outer face of the driving head 3|. All of the connecting rods are secured by means of pins 36. The connecting rod just described is immovable with reference to the driving head 3| and constitutes, therefore, a master rod. From Figure 3 it is apparent that it is held against motion with reference to the driving head by means of the enlarged portion 35, as the enlarged portion 35 has an arcuate face which fits closely around the head and prevents rocking of the connecting rod 34 with reference to the head. This provides a very simple mode of locking the master rod to the head so that one rod does not rock with reference to the head.

Each of the pins 36 is provided with a grove which may be seen in Figure 2 and which is shown in dotted lines in Figure 3 and is indicated by the reference character 31. The upper flange 32 of the driving head is provided with an annular groove 38 in alignment with the grooves 37 of the pins. Cotter pins or split pins 39 are employed for locking the crank pins in place. These split pins are merely slipped into the round space formed jointly by the groove 38 in the driving head and the grooves 31 in the connecting rod pins, and consequently locks the pins in place, as shown most clearly in Figure 3. The inner ends of the connecting rods are joined by means of the pins 40 to the pistons l9. It is preferable to bush each end of the connecting rods with a self-lubricating bushing, as indicated at 4| in Figure 3. Obviously it is not necessary to bush the inner end of the master rod previously described.

The body portion is bored out radially for the cylinders and either the pistons or liners for the aouamaa cylinders are @fonmed :o :a self-lubricatin imateniatsuch as,an alloy, qtgraphiteandimetal,sthough obviously the invention is not to be limited to this. specific material, as any other :se1t-..luhrioat ingmaterial, having long wearmayabeused.

in the form of .the invention shown liners'liz (itself-lubricating material-:are provided for each cylinder. These liners are forced into the cylinders .from the outer .side -inwardly until they strike small flanges -,43 carried at ':the ,-inner ends of the cylinders. The pistons are ,preferabiy provided .with piston rings .as indicated and may be made of :any suitable materiel, such as least iron. These ,pistonsslide .freely within the :selflubricating sleeves and thus useof oil either (811 the pistons or at the crank or :at any of the joints, of :the connectingrods is wholly avoided.

.In-the preferred :form of the invention, a disk valve 44 is provided and is pressed inwardlyrhy meanscf a spring-.45. This valve ;is provided with a :guiding stem 46 integral therewithaand uided withina recess formed-in the valve plate-or valve guiding means 47. One of these plates is provided tor-each valve, as is obvious .frcm.-Fig ures this self-lubricating material. 7

I he body portion is provided with an annular discharge chamber 48 which circumscribes =the cylinders and which opens into an enlarged portion :49. communicating with the tank by means of the pipe .6 :as shown in Figure 2. Thus :acommon annular discharge passageway is provided in the body portion of the -compr.essor itself into whicheach radially 'disposed ic linder dischar es.

The inlet for each of the cylinders is provided by means of one or more apertures 5.0 which-are drilled downwardly through the -.cylinder wall, as shown in Figures 2 and 3. These apertures communicate with an annular intake passageway 51 and if desired, :the,annularpassageway 15.1 may open into the small segmental passages or spaces 52 between the cylinders. The annular passageway5-l is provided with a removable annular filtering pad or member 53 preferably supponted by a .gauze screen '54.

The inlet chamber of the -a.i r -;.compress or ;is thus completely separated ofi from the motor by means of the transverse wall 24. This inlet .por-

tion'receives 13111 from the outside through aperthrough the relatively large extensive area of the annular intake passagers'l with "the cylinders. The filtering pad or member '53thus presents a very extensive surface to the air entering the Qylinclers, although the actual apertures leading to the cylinders may be relatively much smaller as indicated. Thus there is no material .restric- I tion ,to the :free .air flow to the cylinders.

V The bottom portion of the :tank fits over the should part 56 of the .cQmPIBSSOr unit and lobkedthereto'ibyzmeans:ofsscrewsfifi.seerfieurez, so zthat the=tank :is rfreelyiremovable.

to be understood. that other iforms of valves may ibe :used. for example, .as shown "in Figure 5., the valve ca-p. 59 :maybe :providedwith a hall waive 6D pressed'inwardly by means :of :a spring 151 acarried rby azremovable ccaplike member 62. .I'his-.valve "mayseat land plose an aperture '63 leading intowthe :cylindenand.dischargeapertures 6.4 may be :provided as shovm in Figure It is preferable, in the zeventsthis'ztyne iof. valve-is :used, to provide 3a small gasket 265 for each valve cap. tithe uppermortioneofithe tank carrieszapressure responsive automatic switch indicated generally atiGB in E'Eigure i4 and connected to the motor tm'ough; the medium Of the cable .61. This cable extends :outwardly ia-hovethe .top 168 vofxthe tank Tl. through an aperture in the sidewall and is covered :by 'ana ornamental qmeta'l :conduit 69 rigidly seonred.toitheztank, see "Figures land 4. This conduit mxtends downwardly and. carries a plug or other :member :fits a complementary member 51;! supported from .an enlargement .12 formedronthe ornamental bottom (or-base .por-

tion i4. Thus :when the tank :isremoved, it is obvious that :no thought :need be given the wiring as the tank and the :rigidiy :attached member 10' may he :lifted directly from the compressor. and may be .replaced, athus .reestablishing the motor circuit.

The top of the tank alsozcarries a reducing'valve l3,isee Figured, controlled by a :knob 14 projecting through-the can. It is :also preferable to provide Pfihfl :automatic pressure responsive :switch 66 with a manual cut-off :15 which .proj ects through the atop of :the cover'li, as-showrn in .Figlure ,1. Also it preferable :to provide a gauge '16 for indicating the pressure within the :tank and a;gauge I1 communicating :with :the discharge pipe 1-8 so :that thereduced pressure maya-lso be read. V

311; will abezseen zpartioularlyirom Figure 1 that the tank merges uniformly into the cap '5 at :the upper endiand at the lower end the compressor and motor unit and supporting base form, ineffect, a continuationof the :tank so that there are no exposed aoperatingparts -on the one :hand, and, on the, other hand, so that a very compact and ornamental structure results.

It is to be particularlynoted that the tankmay be most easi y removed .-f-rom ,the rest of the apparatus by merely loosening one of the fittings, for instance the fitting :8, see .Figure 1, and :removing thescrews 58, see Figure 2, which hold the tank to the compressor unit. Thereafter the tank may be lifted directly-tram the base portion of the device.

However, the apparatus isso made that no attention whatsoever is required .iora great length of time. All of the .parts of the compressor are oilless and require no attention whatsoever. Also the motor .is supported by ball bearings and if desired, these hearings may be packed with grease, though obviously this is not necessarily required. The lower bearing I4, see Figure 2, which supports the weight .of the motor, .is easily accessible :by merely removing the cap 19.and this.

hearing may be suitably lubricated.

.It is to be noted particularly .from reference to Figures 2 and 3, that the incoming air entering through the apertures .55 is filtered by the filtering pad 53 and passes :into the cylinders through the apertures 50. It leaves the cylinders and enters the annular aperture 48, -thereafter passing into the tank, preferably a check-valve indicated l-l ally at :80 .infi we 2 being provided, Pardoes not come in contact with theoil or with any oil surface or bearing at any part in its passage either into or outof the air compressor. This feature is of particular importance, as has been explained in detail hereinbefore. Obviously this principle could be used with any number of cylinders,one or more as desired. Preferably, however, the cylinders are multiple, as shown in Figure 3, and are so arranged as to assist in the accurate balancing of the device.

The incoming air enters the respective cylinders when the pistons have been drawn to their inner position, as shown in Figure 2, as the ports or entrance apertures 50 are then uncovered. Thereafter on the compression stroke, the piston covers these openings and the air isdischarged past the valve 44. 1

It is to be noted also that the heavy parts of the apparatus constitute the base, that is to'say,

. the motor and the compressor unit. These heavy parts tend to stabilize'th'e apparatus and the relatively lighter tank structure is supported therefrom. Obviously, vibration is not reinforced by the tank as would have been the case had the compressor and motor been supported by the tank. In actual practice this device has been found very quiet in operation and although of small size, it nevertheless is highly efiicient and can deliver any required volume of air depending on the proportions of the device.

- It .is a portable apparatus, although if in stalled in taverns or similar places, it would be bolted down to its support, such, for example, as the bar, as the device itself is ornamental in appearance. It will be seen further that the apparatus is simple to manufacture and readily lends itself to quantity production.

Although this invention has been described in considerable detail, it is to be understood that such description'is intended as illustrative rather thanlimiting, as the invention may be variously embodied and is to be interpreted as claimed.

We claim:

1. An air compressor comprising anelectric motor having a vertical'shaft, an air compressor supported fromand driven by said motor, a storage tank supported from and fed by said compressor, said motor, compressor and tank forming a unitary structure, pressure responsive automatic control means carried by said tank and controlling said motor, said motor and compressor being detachable from said tank and constituting a base structure, and interengaging detachable electrical connecting means carried by said tank and base structure and respectively connected to said control means and to said motor.

'2. An air compressor comprising a unitary structure having an air storage tank, an air compressor including a rotary shaft, a body portion surrounding said shaft, a. plurality of radially arranged cylinders in said body portion, pistons within said cylinders driven from said shaft, said body portion being located below said tank, and an electric motor mounted below said compressor and operatively coupled to said shaft, the axes of,

said shaft, a plurality of radially arranged cylinders in said body portion,pistons within said' cylinders driven from said shaft,'said body'portion ticular emphasis is laid on the fact that the'air' being located below said tank, and a motor mounted below said compressor and operatively coupled to said shaft, the axes of said tank, said body portion and said motor being in alignment, said tank, said body portion and said motor having external surfaces which approximately align to form a vertical, approximately cylindrical structure.

4. An air compressor comprising a unitary structure including an electric motor, an air compressor supported by said motor and driven by said motor and having a suction compartment, at least one of each relatively movable portion of said air compressor being formed of a material that does not require oiling, a transverse division wall separating said air compressor from said motor and constituting one wall of said suction compartment, and a storage tank supported from said air compressor, the inlet to said suction compartment being located above said compressor.

5. An air compressor comprising a storage tank, an air compressor supporting said tank, an electric motor supporting said air compressor and operativelycoupled thereto, a pressure responsive electrical means carried on top of said tank and controlling said motor, and a cover for said electrical means, said cover, tank, compressor, and motor forming a substantially cylindrical, vertical unitary structure and providing a substantially continuous vertical, cylindrical side wall for the entire structure.

6. An air compressor comprising a body portion having a plurality of radial cylinders, pistons in said cylinders, and a centrally arranged crank for reciprocating said pistons, said body portion having an annular inlet portion provided with a ring of filtering material and having apertures extending from the annular portion into said cylinders and uncovered by the respective pistons when said pistons are at one extreme limit of their stroke.

7. An air compressor comprising a body portion of approximately annular contour and having a plurality of radially arranged cylinders, said body portion having an annular outlet passageway surrounding said cylinders, valves for said cylinders opening into said annular passageway, said body portion having a second annular passageway constituting an inlet portion for said cylinders and having a plurality of apertures communicating with said last mentioned passageway and with the respective cylinders, said apertures being uncovered by the respective pistons when said pistons are at the inner limit of their strokes, and a centrally arranged crank for reciprocating said pistons.

8. An air compressor comprising a body portion of approximately annular contour and having a plurality of radially arranged cylinders, said body portion having an annular outlet passageway surrounding said cylinders, valves for said cylinders opening into said annular passageway, said body portion having a second annular passageway constituting an inlet portion for said cylinders and having a plurality of apertures communicating with said last mentioned passageway and with the respective cylinders, said apertures being uncovered by the respective pistons when said pistons are at the inner limit of their strokes, a centrally arranged crank for reciprocating said pistons, and an annular filtering pad carried within said last mentioned annular passageway.

9. An oil-free air compressor comprising a body portion-having a plurality of radially arranged cylinders, each cylinder having a liner of self-lubricating material, a piston positioned within each cylinder, a centrally arranged crank, means connecting said crank with said pistons, said means having articulated portions, said articulated portions being lined with a self-lubricating material, and a valve for each cylinder, said valves, in their open positions, being out of contact with said liners. V

10. An air compressor comprising a body portion having a plurality of radially arranged cylinders, pistons mounted within said cylinders, a centrally arranged crank, an antifriction head mounted upon said crank and having annular spaced flanges, a piston rod constituting a distinct and separate unit from said head and rigidly locked to said head, and a plurality of piston rods connected to the remaining pistons and pivotally mounted between said overhanging flanges.

11. An air compressor comprising a body portion having a plurality of radially arranged cylinders, pistons mounted within said cylinders, a centrally arranged crank, an antifriction head mounted upon said crank and having annular spaced flanges, a piston rod constituting a distinct and separate unit from said head and rigidly locked to said head, and a plurality of piston rods connected to the remaining pistons and pivotally mounted between said overhanging flanges, the articulated ends of said piston rods being lined with a self-lubricating material.

12. An air compressor comprising an electric motor having a projecting driving shaft, an air compressor comprising a body portion supported directly by said motor and having a floating shaft slidably and operatively coupled to the free end of said driving shaft, said shaft having an overhanging crank thereon, a driving head mounted upon said crank, said body portion having a plurality of radially arranged cylinders, pistons mounted within said cylinders, piston rods connecting said driving head with said pistons, one of said rods constituting a master piston rod and being rigidly coupled to said driving head, the remainder of said piston rods being articulated with said head and their respective pistons, the articulatedend of said piston rods being provided withliners formed of self-lubricating material, and pins passing through said liners and joining said head and the pistons to said piston rods.

13. An air compressor comprising a unitary structure including an air compressor unit having an annular body portion, an electric motor having an annular field structure directly bolted to said body portion and in axial alignment therewith, said electric motor having an armature and a driving shaft, said air compressor having a floating shaft coupled to said driving shaft and having an overhanging. crank, said body portion having a plurality of radially arranged cylinders, pistons within said cylinders operatively coupled to said crank, said body portion having openings'extending outwardly and in alignment with said cylinders, valves located at each opening, and a valve guiding means closing each of said openings, said body portion having an annular passageway circumscribing said cylinders and into which said valves open.

14. An annular compressor unit comprising a ring-like body portion, a shaft centrally arranged and carried in a floating manner by said body portion and having an overhanging crank, a driving head carried by said crank, said body portion having a plurality'of cylinders provided with liners and having openings in alignment with said cylinders closed by caps, valves guided by said caps and controlling the discharge of the said cylinders, pistons mounted within the cylinders and operatively coupled to the said driving head, said body portion having an annular passageway surrounding said cylinders and into which said valves open, said body portion having an annular inlet passageway provided with openings communicating with said cylinders and uncovered by said pistons when said pistons are at the inner end of their strokes, and filtering material carried within said annular inlet passageway.

15. An air compressor comprising a body portion having a plurality of cylinders, a shaft pivotally mounted within said body portion and having a crank, a head carried by said crank, said head having a groove formed therein, pistons Within said cylinders, connecting rods joining said pistons and said head, at least one of said connecting rods having a pivot pin operatively connecting such rod and said head,

said pivot pin havinga notch formed therein registering with'the groove formed in said head, and a locking pin carried jointly by said groove and said notch for locking said pivot pin to said head.

16. An air compressor comprising an electric motor having a vertical shaft, an air compressor unit supported and driven by said motor, and

7 an air storage tank supported and fed by said compressor, said motor, compressor, and tank forming a unitary structure and each being substantially symmetrical about a vertical axis, said tank being complete in itself and having a closed bottom, said air compressor unit being a complete unit independent of said tank.

ADAM ZISKA. CONRAD A. BIEBLER.

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