US2489877A

US2489877A - Peening apparatus

Info

Publication number: US2489877A
Application number: US7261A
Authority: US
Inventors: Bert F Fowler
Original assignee: Studebaker Corp
Current assignee: Studebaker Corp
Priority date: 1946-05-02
Filing date: 1948-02-09
Publication date: 1949-11-29
Anticipated expiration: 1966-11-29

Description

Nov. 29, 1949 B. F. FOWLER PEENING APPARATUS Original Filed May 2, 1946 4 Shets-Sheet 1 IN V EN TOR.

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Nov. 29, 1949 B. F. FOWLER PEENING APPARATUS 4 Sheets-Sheet 2 Original Filed May 2, 1946 INVENTOR. M

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Nov. 29, 1949 B. F. FOWLER I PEENING APPARATUS 4 Shets-Shet 5 Original Filed May 2, 1946 INVENTORL @a/WW M' ATTORNEYS.

Nov. 29, 1949 B. F. FOWLER 2,439,377

PEENING APPARATUS Original Filed May 2, 1946 4 Sheets-Sheet 4 INVENT OR.

A BY

TTORNE YS.

Patented Nov. 29, 1949 The Studebaker Corporation, South Bend, 1nd, a corporation of Delaware Original application May 2, 1946, Serial No. 666,773. Divided and this application February 9, 1948, Serial No. 73261 11 Claims. (01. 51 -15) My present invention relates to an improve ment in peening apparatus of the type in which shot is caused to be projectedupon metal articles to remove fissures or other imperfections therein and thereby materially increase the mechanical strength of the article.

My present application is a division of my on pending application Serial No. 666,773 filed May 2, 1946 So far as I am aware most prior forms of apparatu's of the above character usually comprises a centrifugal Wheel upon which shot is caused to be fed and which wheel is rotated at high speed so that the shot is projected by centrifugal force with considerable force upon a metal article being peened.

These prior forms of apparatus are unsatisfac tory for several reasonsv Perhaps, the foremost disadvantage lies in the fact that it is diflicult to control Within narrow limits the desired peening of an article with the shot. This difficulty is due to the inability to effect the control in such apparatus of the amount of shot being projected upon an article with a predetermined amount of force so that the resultant peening of the article is not always uniform Further, such prior apparatus is only effective to project shot in the plane or ro tation of the centrifugal Wheel, and for irregular- 1y shaped articles is unsuitable in that only that part of the article caused to be passed through the plane of rotation of the wheel is caused tob'e peened.

It is an object of my present invention to provide peening apparatus having nozzle means through which shot is adapted to be discharged comprising Work supporting means of a character for subjecting substantially all portions of an article supported thereon to the shot discharged through the nozzle means.

A further object of my invention is to provide peening apparatus having nozzle means through which shot is adapted to be discharged comprising work supporting means for supporting an article to be peened, drive means for driving the work supporting means, and means under the control of the driving means for controlling the delivery of shot and air under pressure to the nozzle means for discharge of the shot through the nozzle means upon the article to be peened.

A further object is to provide an apparatus as last aforesaid having means for automaticany controlling the flow of shot and air u'r'iderpres sure to the nozzle means for a predetermined length of time providing a cycle of operation for the apparatus in the peening of article therewith.

In order to accomplish the aforesaid objects, I;

propose to provide an apparatus having a work supporting member for supporting an article to be peened. The apparatus further comprisesa hopper or other suitable receptacle for support ing shot to be uses in the eening operation, and

which shot through suitable valve means is adapted to be delivered to a conduit feeding into a nozzle means through which the shot is to be discharged 111 3911 th'wfifik SliiJiJbltd the work supporting member; The nozzie means further is' adapted to have Gr-ihetlhii through a conduit with a source of air under pressure with air under I ressure flowing through the nozzle means being e-Iie'ctive to discharge therefrom the shot being fed from the hopper to project the shot upon the article. Thus the shot to be projected upon the article is aused to be ueiiveredto the nozzle means, and the air under pressure is effective to cause the shot to be impinged upon the article with the force thereof being controllable by com predetermining the amount oi shot delivered to uienozzie means.

The previousi'y referred to valve means con:

trolling delivery or shot to the conduit leading to the nozzle means together with valve means nozzle means are caused to be automatically closed upon the completion of a cycle of a predeconnecting the air pressure conduit with the termine'd length of time of treatment or an article with the shot. Upon completion or such cycle, the valve means for the shot and the air caused to be closed terminating the predetermined period of shot blasting of the article.

In the preferred form or my invention the valve means oontroning the delivery (if shot to the I nozzle means and the nozzle means are provided with replaceable orifice members for controlling the amount of shot adaptedto be delivered to the a nozzle means and the velocity of air under pressure adapted to be delivered there through to com trol the amount and force with which the shot is 5 caused to be impinged upon an article being 1 treated;

The aboveand other objects-anti advantages of my invention Will appear from the detail de i scription.

Now, in order to acouamt those skilled in the j art With the manner of constructing and utilizing j apparatus in accordance with my invention, I

shall describe in connection wit the accomw 3 panying drawings a preferred embodiment of my invention.

In the drawings:

Figure 1 is a front elevational view of apparatus constructed in acordance with my invention with the upper housing portion of the apparatus being broken away to illustrate the supply hopper for the shot and associated parts;

Figure 2 is a side elevational view with certain parts being shown in section, and with the enclosing housing of the apparatus removed to show the manner in which an article is adapted to be supported and rotated within the shot blasting chamber of the apparatus of Figure 1;

Figure 3 is a plan view of the portion of the apparatus shown in Figure 2;

Figure 4 is a detail vertical sectional view taken substantially on the line 44 of Figure 2 looking in the direction indicated by the arrows illustrating timing cam means for controlling the cycle of operation of the apparatus;

Figure 5 is a detail vertical sectional View taken substantially on line 5-5 of Figure 1, looking in the direction indicated by the arrows with certain of the parts being broken away and shown in section for clearness of illustration;

Figure 6 is a plan view of a portion of the control means for controlling the flow of shot and air under pressure to nozzle means for projecting the shot upon an article being treated; and

Figure 7 is a detail lengthwise sectional view through a preferred form of nozzle means of the apparatus of my invention.

Referring now to Figure 1,- the apparatus ll} of my invention comprises a supporting platform ll formed of suitable structural steel frame members for supporting a housing l2 which in the embodiment of my invention herein disclosed comprises a pair of shot blasting chambers l6l 6, in which articles to be shot blasted or peened are caused to be supported upon a work supporting platform means i'l, shown in detail in Figures 2, 3 and 4, with each of the chambers It being adapted to be closed at the front of the apparatus by doors Iii-i8 hingedly mounted as at It along opposite side edges of the front wall of the apparatus. Suitable known link locking mechanisms are associated with each of the doors l8l8 and are operable through the handle members 2| for opening and closing the doors and through which the work to be shot peened is adapted to be disposed within the chambers l6l5. The doors l8 are further provided with windows 2| through which peening of the articles may be observed. 7

In the particular form of apparatus i2 shown in the drawings a pair of chambers I6 are shown, and the description of my invention hereinafter will be limited to the means associated with the chamber at the left of Figure 1 for efiecting the shot peening of an article disposed therein, it being understood in the apparatus shown the parts hereinafter described are duplicated for the other or right chamber of Figure 1 to provide an apparatus in which two parts may be caused to be shot peened by a single operator of the apparatus.

Referring now more particularly to Figures 2,

4 unit 24. The output shaft of the gear reduction unit has a pinion means suitably keyed thereto as by means of the intergral sleeve 25 thereof having drive fitting engagement with the output shaft of the gear reduction unit 24. A pinion 21 at the outer end of the sleeve portion 26 has meshing engagement with a gear 28 carried by a shaft 33, the opposite ends of which are suitably journaled in ball bearing assemblies supported within a pair of brackets 32, 32 carried on a horizontal extending frame or panel member 3!. A pinion means 33 is also suitably secured to the shaft and the teeth 34 integral therewith has meshing engagement with a gear 35 keyed to a shaft 36 which is journaled intermediate its ends inv a suitable bracket 31 and with the shaft 36 at its outer end being rotatably supported in a bracket 38 fixed to member 31. The shaft 36 at its inner end has a cam 39 suitably keyed thereto with the inner end of the shaft 36 having connection with a shaft 40 by means of a keying member 4! of known construction. The inner end of the shaft 40 has a bevel gear 43 fixed thereto with the inner end of the shaft 49 being saitably supported and mounted for rotation in a gear box housing 44 of known construction. The bevel gear 43 is adapted to have constant meshing engagement with a bevel gear 45 fixed to one end of a vertically extending shaft 48 which at its upper end is journaled in a ball bearing assembly 58, the outer race of which is supported in the upper end of a sleeve portion 53 extending coaxially of the shaft 43 of a supporting member 54, and which sleeve portion is enlarged to form a closure plate portion 55 forming part of the gear housing 44 and in which a second ball bearing assembly 56 is provided for rotatably supporting the shaft 48. The shaft 48 at its upper end is provided with a reduced end portion 51 adapted to fit in a socket formed in the work supporting member I? with the work supporting member I? being further formed with an annular enclosing housing portion 58 into which the upper end of the sleeve portion 53 surro ending the shaft 48 projects and providing a support for rotation of the work supporting member 11, together with the shaft 48 about the axis thereof. A cap member 69 is provided with an annular sleeve portion 6| fitting over the reduced upper end 59 of the shaft and a nut 62 is adapted to have threading engagement with the upper end of the shaft to secure the member in position to support an article 63 to be treated in the chamber it of the apparatus. The article 63 as shown in the embodiment of the apparatus of my invention herein disclosed is an articulating rod which is adapted to be secured in the position shown by the member 63 by the means described and in which the radially projecting arm portion 54 of the work supporting member I! is provided with a pair of upwardly projecting pins 65) between which the outer end of the articulating rod is disposed so that the articulating rod is caused to be rotated with the work supporting member I! when the shaft 48 is rotated.

As shown more clearly in Figure 5 the collar or sleeve portion 53 of supporting member 54 is provided with a plate portion 10 secured along opposite side edges thereof on a pair of spaced I- frame members 'H1I extending lengthwise of and parallel of the axis of the shaft 43 and resting upon a panel 12 closing the lower end of the chamber l6 and together with suitable framing members supporting the several parts last described.

Quasar it'ef erringinow more particularly: .to Figures 2;; 3; and 4, it will: be. observedzthat the cam member; 39: provided with a substantially-g. V-shaped, notch13 extending inwardly at al-pcrtion of-the. circumference thereof, and; into which notchasroller I4. carried by a pin fixed inanzear or lug 'I6 of alever "I5 is adapted to have engagement The-lever 82 is pivoted tothe angleiron member 83 as at 85, and at 86 has pivotal=connectionz with a horizontally extending rod 81 supported forhorizontal reciprocal movement in a blockv As shown moreclearly in Figure 6, the rod 81 has connection at its other 88- (See Figure 6) endwith-anarm 88' secured to a vertically extending shaft 89 supported in a collar member- 90 supported ona transversely extending plate or-panel member 92 forming the upper end of the chamber I; Alever 93 is connected-to the shaft 89 and has a link 94' pivoted at one end thereto and at its other end to a connecting joint 95 fixedto the valve actuating handle '96 of an air valve" 91-with a second link 98 extending fromthe connection 95 to a c0nnect0r-99 fixed to -a valve actuating handle member I00 for a second-air valve I 02. A rod or link I03 has pivotal connection adjacent the outer end of-the arm 88' atone end and intermediate its ends has pivotal connection with'an arm I fixed toshaft I06-with a second arm I01 alsofixed to shaft 106 having pivotalconnection at its other end with one end of alink I08, the other end of which has pivotal connection at I09 with a valve H0 pivoted at its opposite end as at III. The other opposite end of connecting link or rod I03 has pivotal connection with a link II3 fixed to shaft H4 and to whichis also fixed a second link I I-5 having pivotal connection at its outerend with one end of-a rod or link I I6, the opposite end of which has pivotal connection with one end of valve I I1 pivoted at its other-end as at I I8. A third-arm H9 is also fixed to shaft I I4 and has pivotal connection at its outer end with'a first link or rod-- '9' having pivotalconnections as at I with a'valve I2I pivoted as at I22 and with a rod or link' I23 extending from the pivotal-connectionof the link I IS with the valve I22,- having pivotal connection with one end of a valve I24 and with t e other end of valve I24 being pivoted as at I25; 7

Thearrangement is such that upon rotation of the timing cam 39 the roller I4 is adapted to ride on'the periphery of the disk or cam element 39 inwhich position the connecting rod 'or link 80 is urged upwardly and which movement of the rod 65 of-therod 81 to the right; as viewed in Figure 6, rotating the several arm members described in 'a afl through the lever member 82 effects movement clockwise direction as viewed "in this figure, and

in -which position air under pressure is causedto be delivered from a manifold I through thepair of; valves Q-I'and I02; and with'the several valvemembers H9, H1, HIV and [Mr-being moved $01 open pcsitionthe purpose of whichwill be referredto hereinafter. It will be understood that" thexmanifold I 30- 1 has; suitable: connection .to: a-

781mg .orificermember' :I 63 in position in the nozzle source of: air underpressure; I as -for example :a suitable air-compressor (not'showmfto provide for the flow of air under pressure through :the I valves Bland I02 forv apurDose-to be described. Uponvcontinuedrotation of the cam member 39 the roller 14 drops into the. vl-shapedinotch I3 extending; inwardly of the periphery thereof whereupon the lever member 15 is caused to I assume theposition shown in Figure 4, and inwhich gposition downward movement oflthei rod or link- 80 effects closingnoffthe air valves 91, I02 and the several valve membersIIU, II'I, I21, and I24tcclosed positiontby movement ofthe rod 81 to the r-l left-as-shown in Figure 3 through the-linkageabove described.

Referring now more particularly to Figure 5,

it will besobserved that a hopper I40 is disposed* at'the'upper end of theframe of the apparatus: and is adapted to contain the shot-usedforpeen- I ingof the articulating rod 63 supported on the work: supporting member I1.

The hopper I40 has disposed-in thelower bottom wall thereof a plurality. of discharge metering members I42 mounted in brackets I43 suitably" secured thereto and at-the lower ends one each of which the valve-members II 0, H1, I2I' and I24; previously described, are disposed'below the discharge ends of .the bores I44 which are'adaptedto be opened and-closed by-these several valve members, and

which valve members'in their open position as when the roller I4 is engaged with the outer pe-' ripheral surface of-the timing cam member '39 are in their open position so that shot is adapted tobe' dischargedtherethrough into the funne1-- shaped members I45 disposed therebelow.- The funnel members I45 extend into the open upper ends of a plurality of conduits I46-of rubber or other suitable flexible material, and which at their outer ends aresupported in metal sleeve members ll suitably secured in the annular brackets I50 securedto the upper surface of the transversely extending panel member 92' enclosing-the upper end of-chamber I6. The conduits I46'eachextend to a nozzle I5|','shown in detail .inFigure 7. Also, as shown-in Figure 5, a pluv rality of a air hoses I53, extend from air'valves such as the air valves 91 and I02, previously described, with each of-the air conduits also ex-' tending to one ofthe nozzle means I5I. In the embodiment disclosed each of the air valves 91 r and l02'have connection with a pair of conduits I53 one of which extends to a nozzle I5I. Suitable angle bracket'means indicated generally at I55 provides for the support of the several nozzles I5I-of which there are four in the embodiment of the apparatus disclosed, in theposition shown in Figure 5, and in a position to direct shot upon thearticulating rod 63 'for peening the latter;

The supporting "bracket means further provides. 1 for adjusting the positions of the nozzles within the chamber l6.

Referring now more particularly to Figure 7; it willbe observed that the shot supply conduit I46 in the nozzle shown is secured in an annular sleeve-portion I 51 formed integrally of nozzle housing member I58 with the housing I58 being v formed with a bore I59 in alignment with'the bore of the conduit I46. An air conduit I53 also has connection with a tubular metal sleeve I60 A lock screw. I provides forsecuring the'meter" which, as shown in Figure 7, is-provided with an enlarged "end portion I62 having threaded en--- gagement with a metering orifice member I63 fitting in-ta bore I64: in the nozzle housing I58-.

7 housing I58. The nozzle housing member I58 is provided with a cylindrical member I65 having threaded engagement with a'tapped counterbore I1I' extending coaxially of a bore I66 intersecting the bore I59. An annularwasher I61 is disposed adjacent and seats upon a shoulder formed at the outer end of the bore I66 and is secured in position by means of the aforesaid threaded engagement of member 165' with the nozzle housing. A sleeve member I13 is disposed withinthe member I65 and is retained therein by the turned in outer end of the sleeve I65. The sleeve I13 is provided with a discharge bore I14 which, at its inner end, is provided witha funnel shaped portion I15 maintained in alignment witha circular opening or passage I11 formed in the washer I61 and into which the outer projecting end of the reduced cylindrical portion I18 of the metering element I63 projects. A resilient nozzle member I86 fits over the sleeve member I65 and at its inner end over the projecting end of the housing I58 at the counterbore I1I thereof receiving the member I65 and at its outer end is provided with a flared opening I 82 through which the shot is caused to be projected upon the articulating rod 63 shown in the work supporting member I1. It will be observed upon air under pressure being admitted to the several conduits I53 to ,each of the nozzles I5I that the shot being fed through the conduits I 46 into the bores I59 and the intersecting bore I66 that it is caused by the air being discharged through the reduced portion of the metering orifice members I63 to be discharged through the bores I14 of the members I13 upon the articulating rod 63.

The shot being discharged through the nozzle means I5I may be controlled by the provision of adesired metering member I44 at the lower ends of the hopper for eifecting a predetermined rate of flow of shot into the several conduits I46 and together with the incorporation of the nozzle means I5I of an orifice member I63 providing for the delivery of air under pressure at a predetermined velocity to effect the discharge through the nozzle means of the combined air and shot through the bore I14 of the member I13 I to provide for the peening of the articulating rod- 63 with a predetermined amount of shot and propelled at a predetermined force.v The screw 65 provides for the ready substitution of metering orifice member I63, as desired, and the metering orifices I44 at the lower ends of the hopper are suitably carried in the detachable supporting bracket members I43 to provide for the substitution thereof to provide for a predetermined delivery of shot into the conduits I46.

It is believed that from the above description of the embodiment of an apparatus constructed in accordance with my invention that the operation thereof will be readily understood. However, briefly, it will be seen that with the apparatus disposed in the position .of the timing cam 39 shown in the drawings that the air valves such as that shown at 91 and I82 for the vdischarge nozzle member means I5I, and together with the 7 valve members for the shot discharge metering elements M2 associated with the chopper con- 5 taining the shot in closed position that the door I 8 may be opened and an articulating rod or; other article to be treated suitably assembledupon the work supporting member I1. After the 'r': article to be treated has been arranged on the. work supporting member the door I8 to the se- I lected chamber I6 is closed and a tripping switch (notshown) is actuated to cause theelectricmois being rotated within the chamber I6 with theshot being projected in predetermined amount and with predetermined force upon the articulating rod 63. Preferably, the gear ratios between the pair of bevel gears 43 and 45 and the cam member 39 are such that upon one rotation of the cam member 39 the work supporting member is caused to be rotated once, or more if desired, and when the cam member reaches the position shown in Figure 3 the roller 13 drops into the V-shaped notch 14 shutting off the supply of air under pressure to the several nozzles I5I and of shot to the conduits I46 leading to the nozzles I51. As

shown in Figure 4 the cam 39 has a switch actuating member I96 associated therewith and which is adapted to trip a switch I9I to stop the electric motor 23 and thus completing one cycle of operation for the apparatus so that the door I8 may now be opened and the treated article removed and another article to be treated arranged upon the work supporting member I1. The lower end of the apparatus is provided with a suitable collector pan I85 for collecting the spent shot which after being cleaned and graded is returned by suitable known means to the hopper. Also, as shown in Figure 5, a suitable conduit 186 to dust collector has connection with the chambers I6. It will be understood as previously related that the mechanism is duplicated for the other compartment I6 shown at the right of Figure 1, so that if desired a single workman may cause the alternate operation of the shot blasting apparatus associated with each of the chambers so 'that, during the removal and insertion of one article in one of the chambers an article in the other of the chambers is undergoing shot peening.

I have above described the general nature and arrangement of an apparatus constructed in accordance with my invention, and it will be observed that the several nozzles may be readily adjusted upon the angle iron supporting bracket means I 55 to provide for the arrangement of the nozzles with respect to the work to achieve the most advantageous shot peening of the metal articles being treated. It will be understood that I44 providing for the feeding of a predetermined amount of shot through a conduit leading to a discharge nozzle which has associated with it a conduit for directing air under pressure thereto,

and which-by means of the association therewith of; selected metering orifice members I63 provides for the. discharge'from the nozzle of the shot ldelivered thereto with a predetermined amount of force to provide" for a predetermined peening of a metal article.

' Thus while I have shown'what I consider to be the preferred embodiment of my invention, it

" tion of work supporting means for rotatably supporting an article to be peened, drive means for rotating said work supporting means, nozzle '-means for discharging shot upon said article,

means including first valve means for delivering shot to said nozzle means, means including second valve means for controlling flow of air under pressure to said nozzle means to discharge the shot delivered thereto by said last named means,

and said drive means including means for conjointly' controlling opening and closing of said first and second valve means.

2. Peening apparatus-comprising the combination of a rotatably mounted work supporting member for supporting an article to be peened, drive means for rotating said work supporting member, nozzle means for discharging shot upon the article adapted to be supported on said work supporting member, a hopper for supporting a supply of shot, first valve means associated with said hopper and operable in its open position to efiect discharge of shot from said hopper, first conduit means for receiving shot discharged through said first valve means and conducting the same to said nozzle means, second conduit means for conducting air under pressure to said nozzle means for discharging therefrom shot delivered thereto through said first conduit means, second valve means associated with said second conduit means and operable for closing the same to prevent flow of air under pressure therethrough, and cam means associated with said drive means and said first and second valve means for effecting conjointly opening and closing of said first and second valve means.

3. Peening apparatus comprising the combination of work supporting means for rotatably sup-' porting an article to be peened, drive means for rotating said work supporting means, including a shaft means having gear means between the latter and said rotatably mounted work supporting member for rotating the latter, nozzle means for discharging shot upon the article adapted to be supported on said work supporting member, a hopper for supporting a supply of shot, first valve means associated with said hopper and operable in its open position to effect discharge of shot from said hopper, first conduit means for receiving shot discharged through said first valve means and for conducting the same to said nozzle means, second conduit means for conducting air under pressure to said nozzle means for discharging shot delivered thereto through said first conduit means, second valve means associated with said second conduit means and operable for closing the same to prevent fiow of air under pressure therethrough, and means associated with said drive means and said first and second valve means including a cam member rotatable with said shaft means for conjointly controlling opening and closing of said first and second valve means in predetermined positions of said work supporting member.

4. The combination of claim 3 characterized a 10 by said drive means including said cam member beingadapted to effect closing of the first and second valve means upon a single revolution of said work supporting means. 7

5. Peening apparatus comprising the combination of a rotatably mounted work supporting member for supporting an artice to be peened,

driving means :including a shaft means having gear meansbetween the latter and said rotatably mounted work supporting member for rotating the latter,nozzle means for discharging shot-upon the article adapted to be supported on said work supporting member, a hopper for supporting --a supply. of; shot, first valve means associated with said hopper and operable in its open position to effect-discharge of shot from said hopper by gravity,,-first--conduit means forreceiving shot discharged through said first valve means and for conducting the same by-gravity tosaid nozzle means, second conduit means for conducting air under-pressure to said nozzlemeans for'discharging therefrom shot delivered thereto through said first conduit means, second valve means associated with said secondconduit'means andxoperable for closing the same to prevent flow Ofiflll under pressure therethrough, and means associated with said drive means and said first and second valve means and including a cam member rotatable with said shaft means for conjointly controlling opening and closing of said first and second valve means in a predetermined position of said work supporting means.

6. Peening apparatus comprising supporting means for rotatably supporting an article to be peened, means for rotating said supporting means, nozzle means for discharging shot upon the article adapted to be supported by said supporting means, means including first valve means for delivering shot to said nozzle means, means including second valve means for delivering air under pressure to said nozzle means, and means associ ated with said driving means for conjointly opening and closing said first and second valve means at a predetermined position of said work supporting means.

7. Peening apparatus comprising the combination of movable Work supporting means, drive means for driving said work supporting means, nozzle means for discharging shot toward said work supporting means, a, hopper for supporting a supply of shot, valve means associated with said hopper and operable for discharging shot from the latter at a predetermined rate, first conduit means for receiving shot discharged through said valve means and conducting the same to said nozzle means, second valve means adapted to be associated with a source of air under pressure, second conduit means extending from said second valve means to said nozzle means for conducting air under pressure to the latter to discharge therefrom shot delivered through said first conduit means, and said drive means including means for conjointly opening and closing said first and second valve means.

8. Peening apparatus comprising the combination of movable work supporting means, drive means for drivin said work supporting means, nozzle mean-s for discharging shot toward said work supporting means, means including first valve means for delivering shot to said nozzle means, and means including second valve means for controlling flow of air under pressure to said nozzle means to discharge the shot delivered to said nozzle means by said first means, and said drive means including means for conjointly cOntrolling, opening and closing of said first and 1 second valve means. '9. Peening apparatus comprising the combination of movable work supporting means, drive means for driving said work supporting means,

noz zlemeans for discharging shot toward said work supporting means, a hopper for supporting a supply of shot, first valve means associated for discharging therefrom shot delivered 'thereto "through said first conduit/means, second valve means associated with saidsecond conduit means and operable for closing the same to prevent the iiow of air under pressure therethrough, and said 'drive' means including means for conjointly controlling opening and closing of said first and sec- "ond valve means. 1

10. Peening apparatus comprising the combination of movable work supporting means, drive means for driving said work supporting means,

nozzle means for discharging shot toward said work supporting means, means including first valve means for delivering shot by gravity to said nozzle means, and means including second valve means for controlling the fiow of air under pressure to said nozzle means to discharge the shot delivered to said nozzle means by said first means, and said drive means including means for conjointly controlling opening and closing of said first and second valve means.

l1. Peening apparatus comprising movable supporting means for supporting an article to be peened, drive means for driving said work supporting means, nozzle means for discharging shot upon said article, means for delivering shot at a predetermined rate to said nozzle means, and meansfor delivering air under pressure at a predetermined velocity to said nozzle means to discharge the shot delivered thereto with a predetermined force, and said drive means including means for conjointly preventing fiow of shot and air under pressure to said nozzle means.

BERT F. FOWLER.

No references cited.

Certificate of Correction Patent N 0. 2,489,877 November 29, 1949 BERT F. FOWLER It is hereby certified that errors appear in the above numbered patent requiring correction as follows:

In the rant, line 1, address of inventor, for Vero Beach, California, read Vero Beach, Florzda; in the heading to the printed specification, line 3, for Vero Beach, Calif. read Vero Beach, Fla.;

and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 28th day of March, A. D. 1950.

THOMAS F. MURPHY,

Assistant Oommz'ssz'oner of Patents.