US2249771A

US2249771A - Nozzle structure for spray guns

Info

Publication number: US2249771A
Application number: US292187A
Authority: US
Inventors: William B Macmartin
Original assignee: Binks Sames Corp
Current assignee: Binks Sames Corp
Priority date: 1939-03-06
Filing date: 1939-08-28
Publication date: 1941-07-22
Anticipated expiration: 1958-07-22

Description

July 22, 1941. w MacMARTlN 2,249,771

NOZZLE STRUCTURE FOR SPRAY GUNS Original Filed March 6, 1939 3 3 2915 1.5 4 35 16 d g 32 I .14

7 53 Z2 4 fl 11 I} 34 40 INVENTIOR. *3 5 hzffiam/fi 77km 7/Zagjua.

27 ifim ATTORNEY.

Patented July 22, 1941 NOZZLE, s'rauo'rurm FOR. srmr GUNS William B. MacMartin, Lombard, 111., assignor to Binks Manufacturing Company, Chicago, 111., a corporation of Delaware Original application March 6, 1939,

Serial No.

260,040. Divided and this application August 28, 1939, Serial No. 292,187

7 Claims. I (or. 299-1404 The present invention relates to nozzle structures for spray guns, and more particularly to the type having a nozzle unit secured to the front end of the gun body and which is located between said front end of the gun body and the air nozzle cap coupled to the front end portion of the body of the gun.

Such unit is of generally double cone form with the rear cone portion in seating engagement with the front end of the gun body and the forward cone portion in seating engagement with the nozzle cap, and being provided withpa central passage for the passage of the material to be sprayed from the gun body to the material tip of the nozzle and concentrically located air passages for the passage of atomizing air from the gun body to the air orifice in the nozzle cap. Heretofore, the passage of the auxiliary air for the horn or side jet ports has extended from the gun body to the horns carried by the nozzle cap by way of a chamber located outside the unit and within the coupling connecting the cap to the gun body, such chamber being provided between the rear end of the'cap and the front end of the gun body, whereby the auxiliary air will leak out by the coupling, thus rendering the control of the pressure and amount of air at the horn ports uncertain and difiicult.

An object of the present invention is to 'provide a passage in the unit itself for the flow of the auxiliary air from the gun body to the horns which passage is independent from the air chamber in the coupling and also is sealed off from such air chamber whereby there will be no possibility of the auxiliary air leaking out as in previous structures.

In units of the type mentioned, the rear cone portion of the unit comprises axially and radially spaced frusto-conic-al parts which seat against counterpart frusto-conical surface portions at the front end of the gun body, and a threaded part between the frusto-conical parts of the unit engageable with a threaded part between the frusto-conical parts of the gun body. The threaded parts are close to and of but very slightly greater diameter than the rear frustoconical parts so that the proper seating of the frusto-conical parts depends upon the accuracy of fit of the threads of the threaded parts. If the threaded parts are not exactly coaxial with the frusto-conical parts, the latter will not seat properly when the threaded parts are screwed home. Under such conditions, the frusto-conical parts will engage more or less eccentrically and,

the desired sealing of the parts is not effected.

. diameter.

Because both of the forward and rear frustoconical parts mentioned are machined to lie in the same cone surface, the eccentric engagement will apply to both.

The present invention has as another object the provision of means for avoiding such disadvantage .by more greatly spacing the frustoconical parts both radially and axially so that the threaded parts may vary from coaxiality within a fairly wide tolerance much greater than usually allowed in the manufacture of devices of this kind. The forward of the frusto-conical parts is of much greater diameter than the rear one thereof, and preferably at least twice the When the unit is being screwed into place, the frusto-conical parts self-center as they engage or seat before the threads of the threaded parts are tightened. This is possible because of the threaded parts being remote from the frustoconical parts, both radially and axially, and also because the threads extend for the full length of the threaded parts, there being no bottom to limit the threading movement.

Other objects, advantages, capabilities, features and the like are comprehended by the invention as will later appear and as are inherently possessed by the invention.

This is a division of the copending applicationof John Harrison and myself, Serial No. 260,040, filed March 6, 1939.

Referring to the drawing:

Fig. 1 is a side view in elevation of a spray gun embodying the invention;

Fig. 2 is a fragmentary longitudinal sectional view on an enlarged scale of the nozzle structure and the forward part of the gun body; and

Fig. 3 is a transverse sectional view taken in planes represented by line 3-3 in Fig. 2 of the drawing.

Referring more in detail to the drawing, the embodiment selected to illustrate the invention is shown with a spray gun comprising a body i having a handle 2 provided at its lower end with a connection 3 for the connecting of an air duct (not shown) which supplies air under pressure to the gun by way of a suitable duct (not shown) in the gun handle and leading to a. valve controlled air passage 4 in the body of the gun, the air passage 4 leading to the forward end portion 5 of the gun body. To the body I is pivotally connected a trigger 6 operatively associated with a needle valve 1 which controls the flow of material to be sprayed through the material nozzle tip and the' incidental flow of the material through a material passage 8 provided in the forward end portion of the gunbody. The cap between the seats'36 and Man annular air passage 8 has an inlet comprising a connection channel 38 which registers with the air channel 9 for the connecting thereto of a material duct 32. The cap 34 has a pair of horns having (not; hown); I l I ports 40 from which are projected side jets of The forward end portion or; the gun body is 5 air to flatten the atomized stream of material provided with a forwardly widening socket having and airprojected fromthe material tip 20 and a mouth portion ID, a .base portion ll of smaller h e eriflce 4l-\-reSD et ely;, Ports diameter, and an intermediate threaded portion ca s W t n u a i channels 32-" 12 of intermediate diameter. Between the month, y W y Of p se-s zfprovided in the horns 39. portion i0 and the threaded portion-I2 is an an- It w l t us be seen'that the unit referredto is nular air channel l3, and between the base por 1 "g nerally 01 double cone form with a pair of tion Ii and the threaded portion I2 isan annular

V reancone seats

22 and 3! sea-t ns up the c n air channel l4. Both the mouth portion Ill and s" and respectively of the gun body, and the base portion H are provided respectively with W a ei e

forward eone'seats

28 and 30 seatflaring annular or frusto-conical seats l5 and I-B 5r n penzthe cone seats 3E and 31; of the air disposed in the same conical surface and forming nozzle l). wh by e il ry hit for the horn spaced parts thereof, with the channels I3 and Ports W l pass 'through the. part 29 by way of I4 and the threaded portion l2 cut into said 'pe gesiland notpass through the space conical surface and locatedbetween said seats Within the couplinging and-between the rear l5 and iii. Theair channel I4 communicates .end of the nozzle .capj d e, front d t with the air passage 4 by way of a valve chamber H gun body whereby le' egewould occur, the seats I! to be later described. In the body portion 5 l dit-electing toseal on and prevent is also provided an air passage l8 connecting with the entering n o-su h, a e W n the c011- valve chamber 43 for establishing communication v l i ng." Because of the m nner, of ee n e between the valve chamber l1 and passage 4, and? the n e to th'e' unib'ody b'y a coupling t air channel |3 ring betweenthe rear. end of the cap and the Fitted to the socketed forward end portion of r a d end of h n b dy -there s an annular the gun body is a nozzle unit comprising a ma-- Space between t 'iee i he E dy w ch s terial nozzle portion and an air nozzle portion; no -e i yi led f y the a s 01 t e and having the general form of a double cone.1 O iP n d th ring connectionwiththe cap The material nozzle portion comprises a central 'tejp event leakage of air. n p s tubular part IS, the rear end of which co munies.fth t ehoml-portspassed through cates with the material passage 8 and the'for-r. ie space e e t e a e of a from ward end of which tapers into a material tip 20' "5 th a e h t 36 9 8 t P ope p essure for the passage of material to be sprayed-there-z 5 Q i h a h .10 to o ld t be Well mainthrough, such passage being controlled byfthemj eiiied'he ie i di; :By Present, invention, the valve tip 2| of the needle valve 1. The rear end ,1 :j hyP e 1 bo ch "space "and sealin of the tubular part l9 has a tapering annular or m ans is'fprovided between such space and the frusto-conical seat 22 which seats upon and seals 1 pas sa geii the fl with the seat IS in the socket base portion'l l.' 40 P e of h o the'heih 'D tS end The tubular part l9 has a concentric portion PesSeeetheretofmm the f P sa 4 e e 23 which is provided at its rear end with a threadcontrolled; by aside valve shown in Fig. 3. This ed portion 24 for securement with the th'readed Valve d ic comprises 8 Cross-bore in the 8 m portion l2 of the forward portion 5 of the gun Ibedy Providing. a chamber "r d a valve chambody, and which is provided at its forward end e va e Se b t theme with an annular part 25 provided with a for-Q i wp ss e j ii a s f o the c a e 43 to e wardly tapering annular or frusto-conical seat" n l e Channel h pe t t e Valve 25, Extending longitudinally through t seat 44- is controlled by a valve '45 carried at the centric part 23 is a series of airpassages 21 for d Stem having til-Smooth Stem P o establishing communication between air channel a threaded portion and a knob e readand an annular air chamber 28 provided at d o fl being Operative in pe k g nut 49 the front end of the unit parts l9 and 23. In- 1 secured into the outer end of the chamber IT at termediately of the length of the concentric porj a i O e g y- At t s de of the nut tion 23 is integrally provided an annular part 29 49 1s a p c s d y a p essu e plate which has a forwardly tapering annular or frusto- 5| ed. 1113011 by a Spring o a ng conical seat 30 and which further has rearwardly' the pack ng leak-ti ht a ou the Smooth DOI'tiOII of the seat 30 a rearwardly tapering annular or of the Stem, the Spring 53 reacting against W e frusto-conical seat 3| of larger diameter than 53 011 the m Portion 45 and k d by a cross the seat 30 and which seats upon and seals with P 54 P v in the Stem y turning he the seat [5 at the mouth ill of the socket portion knob 48 e ve. "-45 maybe adjusted to conof the gun body. The

seats

26 and 30 are dis- 15101 e m n a the P s e of the air to posed in the same conical surface and form the homports and e t desired flattening spaced parts thereof, there being an annular air 7 of e material Stream from the p 0- channel 32 cut into the unit between the seats In assembling t un t. which is of generally 25 and 3n w t t annmar t 29 is prodouble cone form, it is connected to the forward vided a series of forwardly converging air pasend Portion o the un, body by screwing the sages 33 which establish communication between threaded P on 410f the unit into the threaded the air channe1s |3 and 32 V vportion ll of the socketed portion 5 of the gun An air nozzle cap -34 is applied to the forward body. As'the cone seats 3| and ii at the mouth end of the unit and is held tightly ,in place by it of the socket and the'cone seats 22 and I6 at the means of a coupling ring 35 screwed to the base of Socket ge and self-center the threaded forward end portion ID of the gun body. ilinit. further turning of the unit eiieete a W g- The cap 34 has interiorly thereof spaced forwardn a ti n between t t eads of the threaded ly tapering annular or frusto-conical seats 36 and D ts and W further a al movement 31 which seat upon and seal with the seats 26 0f the t. thus h y securing the unit with and 30 respectively, there being provided in the all cone seats exactly. coaxial'and' sealed. If the threads are not coaxial they will be engaged or wedged together with sumcient eccentricity so that all the cone seats will be precisely coaxial. The thread of the threaded part I2 is longer than the thread of the threaded part 24 so that there is no possibility of the rear end of the part 24 seating before the seating of the cone seat parts l6 and 22, and I and 3|, as would be the case if the part l2 had the usual socket base against which the rear end of the part 24 would seat. The seating home of the unit is controlled and made exact by the cone seats, which, as above stated, are in the same or a common cone surface.

The air cap 34 isthen coupled to the front end portion of the gun by screwing the coupling 4 ring 35 into place, thus bringing the cone seats the auxiliary air passage comprising the components I8, I3, 33, 32, 3'8, 42 and 40.

In operation, when the trigger is pressed to open the air and needle valves, the air passes through the passage 4, thence through the chamber ll always in communication with the annular channel l4, from the channel 14 through the passages 21 to the chamber 28, and out through the annular orifice 4|. The needle valve opens later and the material projected through the tip 20 is atomized by the air issuing from the orifice 4|. With the side valve 4445 adjusted as desired, the air passes from the chamber ll parts and the base seal and a forward air channel between said threaded parts and the mouth seal whereby said channels are separated by said threaded parts, said rear channel being in'communication with the air passage in the body and the air passage in the unit being in communication with said rear channel, said body having an auxiliary air passage communicating with the air passage in the body and with said forward channel, said unit having an auxiliary air passage therein communicating with said forward channel and with said air nozzle part.

2. In nozzle structure for a spray gun having a body provided with material and air passages leading to the forward end of the body, an air nozzle part connected to the forward end of the body by a coupling means, and a material and air nozzle unit connected between the air nozzle part and the forward endof the body and having material and'air passages communicating with the material and air passages in the body, said body and unit having spaced annular seats which form outer and inner seals of different diameters, and also having spacedly intermediate said seals threaded parts of an intermediate diameter, said threaded parts when joined providing outer and inner air channels which are separated by said joined threaded parts and which are respectively between said joined threaded parts and said outer through the valve 44-45, chamber 43, passage l8, channel l3, passages 33, channel 32-38, passages 42 and side ports to project side Jets to flatten the material and air stream proceeding from the tip 20 and orifice 4|. The passage of the auxiliary air through the passages 33 is within a nozzle part, as 29, which is sealed from the space within the coupling ring and between the nozzle cap and the forward end of the gun body so that there is no chance of leakage of air to'such space.

While Ihave herein described and upon the drawing shown an illustrative embodiment of the invention, it is to be understood that the invention is not limited thereto but comprehends other constructions, arrangements of parts, details, features, or the like, without departing from the spirit of the invention.

Having thus disclosed the invention, I claim:

1. In nozzle structure for a. spray gun having a body provided with material and air passages leading to the forward end of the body, an air nozzle part connected to the forward end of the body by a coupling means, and a material and air nozzle unit connected between the air nozzle partand the forward end of the body and having material and air passages communicating with the material nd air passages in the body, the combination 0 said forward end of said body being provided with a socket of general cone form with cone seats at the mouth and the base of the socket and with a threaded part between said seats, and an end of said unit being of generally cone form to fit in said socket and having cone seats to form mouth and base seals with said cone seats of the body and also having a threaded part between the seats of the unit to join with the threaded part of the body, said joined threaded parts being spaced from said seals to provide a rear air channel between said threaded and inner seals, said inner channel being connected to the air passage in said body and the air passage in said unit, said body having an auxiliary air passage connected to the air passage in the body and said outer channel, and said unit having an auxiliary air passage therein connected to said outer channel and said air nozzle part.

3. In nozzle structure for a spray gun having a body provided with material and air passages leading to the forward end of the body, an air nozzle part connected to the forward end of the body by a coupling means, and a material and air nozzle unit connected between the air nozzle part and the forward end of the body and having material and air passages communicating with the material and air passages in thebody, said body and unit having axially and radially spaced seats which fit together to form forward and rear seals, and also having spacedly between said seals threaded parts which when united form a. joint, said joint being so located as to provide between it and said seals forward and rear annular air channels, said rear channel being connected to the air passage in the body and to the air passage in the unit at a point between said joint and rear seal, said body having an auxiliary air passage between said passage in said body and said forward channel, and said unit having an auxiliary air passage therein between said forward channel and said air nozzle part.

4. In a spray gun structure provided with passages for material and for main and auxiliary air and having a body, a nozzle unit and an air nozzle cap; a sealing means comprising spaced seating means between the rear end of the unit and the forward end of the body, and securing means intermediate said spaced seating means for securing. the unit to the body and being spaced from said seating means to provide main and auxiliary air channels which respectively form parts of said main and auxiliary air passages, said cap being seated on the forward end of the unit.

5'. In a spray gun structure of the character disclosed and which comprises a body provided with material and main and auxiliary air passage portions therein, a nozzle unit provided with material and main and auxiliary air passage portions therein, and an air nozzle cap on the unit and provided with an auxiliary air passage portion; a securing and sealing means comprising .spaced seating means each having counterpart seats on the unit and the body, and securing means spacedly between said seating means for securing and sealing the unit to the body and for providing main and auxiliary air channels between said securing means and said seating means, which main and auxiliary air channels communicate respectively with the main and auxiliary air passage portions in said body and said unit, said auxiliary air passage portion in said unit communicating with said auxiliary air passage portion in said cap.

6. In a spray gun structure of the character disclosed and which comprises a body provided with material and main and auxiliary air passage portions therein, a nozzle unit provided with material and main and auxiliary air passage portions therein, and an air nozzle cap on the unit and provided with an auxiliary air passage portion; a securing and sealing means comprising spaced seating means each having counterpart seats on the unit and the body, and securing means spacedly between said seating means for securing and sealing the unit to the body and for providing main and auxiliary air channels between said securing means and said seating means which main and auxiliary air channels communicate respectively with the main and auxiliary air passage portions in said body and said unit, said securing means comprising threaded portions of said unit and said body 0! which the threaded portion of said body extends for the full distance between said main and auxiliary air channels for aiIording full and exact seating of said seating means, said auxiliary air passage portion in said unit communicating with said auxiliary air passage portion in said cap.

7. In a spray gun structure of the character disclosed and which comprises a body provided with material and main and auxiliary air passage portions therein, a nozzle unit provided with material and main and auxiliary air passage portions therein, and an air nozzle cap on the .unit and provided with an auxiliary air passage portion, a securing and sealing means comprising spaced seating means each-having counterpart seats on the unit and the body, and securing means spacedly between said seating means for securing and sealing the unit to the body and for providing main and auxiliary air channels between said securing means and said seating means, which main and auxiliary air channels communicate respectively with the main and auxiliary air passage portions in said body and said unit, said securing means comprising threaded portions of said unit and said body of which the threaded portion of said body is longer than the threaded portion of said unit for effecting exact seating of said seating means, said auxiliary air passage portion in said unit communicating with said auxiliary air passage portion in said cap.

WILLIAM B. MACMARTIN.