US3011720A

US3011720A - Gas valves

Info

Publication number: US3011720A
Authority: US
Inventors: Richard O Ives
Original assignee: Harper Wyman Co
Current assignee: Harper Wyman Co
Priority date: 1959-07-21
Filing date: 1959-07-21
Publication date: 1961-12-05
Anticipated expiration: 1978-12-05

Description

Dec. 5, 1961 R. o. lvEs 3,011,720

GAS VALVES Filed July 2l, 1959 3 Sheets-Sheet 1 y, ggg l/ j/rver off-J @rn/@java R. O. IVES GAS VALVES Dec. 5, 1961 3 Sheets-Sheet 2 Filed July 2l, 1959 Dec. 5, 196.1 R. o. lvEs 3,011,720

GAS VALVES Filed July 21. 1959 5 sheets-sheet s United States Patent O 3,011,720 GAS VALVES Richard Q. Ives, Flossmoor, Ill., assignor to Harper- Wyman Company, Chicago, Ill., a corporation of Illinois Filed July 21, 1959, Ser. No. 828,600 13 Claims. (Cl. 236 99) The present invention relates to gas valves and has for its primary object the provision of a new and improved locking type of gas valve.

A further object of the present invention is to provide a new and improved thermostatic gas valve in which a single handle and valve stem are used both to control the open position of the valve and the temperature setting to be maintained by the valve.

A further object of the present invention is to provide a new and improved valve of the character set forth in the preceding paragraph in which the gas ilow controlling valve element is connected to the handle and stem by disengageabe clutch means and including new and improved means for requiring the ow controlling element to be rotated a predetermined angular distance to insure at least a minimum iiow of gas before declutching can be effected.

In brief, the valve of the present invention is of the locking type. It includes a rotatable gas tlow controlling element, such as a disc, mounted in a housing. The element is adapted Vto be rotated by valve stem means extending outside of the housing and which is both rotatable and axially movable elative to the housing. The stem and element are connected by means enabling the element to be rotated by the stem means. The valve is locked against rotation until the stem means is axially moved a short distance by means including a at of short axial length on the stem and a at on the housing abutting against the flat on the stem means. The ats are movable out of abutting engagement upon axial movement of the stem means, after which the latter and the gas ow controlling element can be turned. The rotatable gas ow controlling element and stem means are connected Iby disengageable clutch means so that a thermostatic control element can be adjusted independently of the gas flow controlling element upon rotation of the stem means subsequent to disengagement of the clutch means. The valve is so constructed and arranged that the disengagement cannot be effected until after the stem means and ilow controlling element have been rotated a predetermined angular distance. This arrangement includes a iiat on the vdve stem means and a cooperating fiat on the housing, one of the iiat constituting structures being resilient in a radial dire-:tion to permit angular movement of the valve stem means. The flats ccnstitute cooperating abutment means permitting axial movement sufficient only to disengage the locking means before the valve stem means is rotated and subsequently permitting further axial movement of the valve stem means to permit declutching of the latter from the flow controlling element. This feature may be used independently of the locking means.

Other objects and advantages of the present invention will become apparent from the ensuing description of an illustrative embodiment thereof, in the course of which reference is had to the accompanying drawings, in which:

FIG. l is a side elevational view of a valve constructed in accordance with the present invention with the valve and thermostat actuating handle omitted and with the valve in an intermediate open position;

FIG, 2 is an end elevational view of the front end of the valve with the valve handle and associated bezel illustrated;

FIG. 3 is a front elevational view of the valve as illustrated in FIG. l, but with the valve in its o position;

ice

FIG. 4 is an enlarged axial cross-sectional View through the valve taken along the broken line 4 4 of PIG. 2 with the valve in an intermediate open position, but with the valve handle and stem means clutched to the gas valve controlling element;

FIG. 5 is a further enlarged fragmentary axial crosssectional View taken along the line 5 5 of FIG. 2 illustrating the operative positions of various operating parts when the valve is locked in its off position;

FIG. 6 is a fragmentary transverse cross-sectional view taken along line 6 6 of FIG. 5;

FIGS. 7 and 8 are views similar to FIGS. 5 and 6, but the valve unlocked in its off position ready to be turned; and

FIGS. 9 and l0 are views similar to FIGS. 5 and 6 but along line 4 4 of FIG. 2 with the valve unlocked, with the valve handle and stem means declutched from the gas ow controliing means and with'the valve on, as in FIG. 4 and with the temperature control in a different position of adjustment.

Referring now to the drawings and first primarily to FIGS. 1 to 4, the valve of the present invention is indicated as a whole by reference character 10. It is adapted to be mounted upon and supplied with gas from a gas supply manifold 12, the mounting being effected by an externally threaded dependent nipple 14 within which is a gas inlet passageway 16. The valve includes, in the main, a valve body 20 within which is a chamber 22 (see FIG. 4) in which is mounted a thermostatically actuated regulating valve indicated as a whole by reference character 24 controlling the ow o-f gas from a manually operable valve 26 including a rotary gas ilow controlling valve element shown to be a rotor valve disc 23. The disc is adapted to be adjusted Iby a handle 30 which is also utilized to select the temperature to be maintained. The valve and operating means may take various forms, that illustrated being of the type disclosed and claimed in the copending applications of Raymond F. Wiberg (case 2), Serial No. 817,519, filed June 2, 1959, and of Norman M. Huil", Serial No. 817,518, filed lune 2, 1959,A and Iboth assigned to the assignee of this application. Accordingly, the valve will not be described in detail, but only sufciently to provide an understanding of the present invention which, as indicated heretofore, is directed 'to improved valve locking means and improved means making it necessary to move the valve handle and gas flow controlling element a certain amount before the gas ow controlling element can be declutched.

The thermostatic valve 24 includes a relatively stationary valve seat 32 adapted to be moved axially for calibration purposes, as by a rotatable Calibrating screw 34. The valve includes also a movable valve member 36 biased away from the valve seat by a spring 38 and the position of which is varied by thermostatic actuating means. The position is varied as by a bimetallic lever 40 having one end 42 associated Wi-th the valve member 36 and its other end 44 operatively associated with the rotatable axially movable shaft 46 havingan intermediate threaded portion 48 movable lby the valve handle 30 to vary the temperature to be maintained by the valve. The position of the lever 40 and, thus, of the valve member 36 is controlled by a thermostatically actuated power device 50 which may be of the diaphragm type and connected as by a capillary tube 52 to a suitable sensing uni-t (not shown) which may include a thermostatic capsule maintained in Contact with the bottom of a cooking vessel placed on a burner to which the ow of gas is controlled by the valve 10. For convenience, the thermostatic power device 50 may be mounted upon an end plate 54 closing the recess 22 and supporting also an outlet hood 56 communicating with a gas outlet passageway receiving tongues 70A of the bezel.

58 and through which gas ows to the burner in conventional manner.

The flow of gas to the thermostatic valve is controlled by the ymanually operable rotatable rotor disc 28 which has a planar face 60 abuttingV against a planar face 62 formed on the valve body. The body and disc may be provided with suitable passageways interconnecting the passageway 16 and the recess 22 via the thermostatically operated regulating valve 24. The passageways may be such that they enable the valvepdisc 28 to be moved between olf and full on positions to provide a manually regulatable how of gas to the burner as between a low flame setting 64 and a high flame setting 66 indicated on the valve handle (see FIG. 2) in cooperation with an indicating dot 68 on a bezel 70 associated with the valve handle and supported upon a bezel mount 71 fixedly secured to the housing and having opposed slots 71A The off position of the valve is indicated by `a radial boss 72 on the handle when it is under the dot. In FIGS. 1, 2 and 4 the valve V is shown at an intermediate position to provide an intermediate height flame. In this position, gas ows from the inlet passageway to rotor passage 74 and to a passageway 76 in the valve body leading to the thermostatic valve 24 and, hence, to the recess 22. For additional details of a construction which may be used, see the above referred to Wiberg application.

The rotor valve disc 28 is mounted in a housing or casing 78 having a larger diameter inner portion 80 and a smaller diameter axially extending outer portion 82, which are interconnected by a front wall 84 spaced some distance forwardly of the rotor 28. The casing is secured to the valve body by suitable means such as screw bolts 86.

The valve handle 3G is connected to the rotor valve disc 28 by valve stem means 90 and clutch means 92, whereby the rotor disc may be turned by or declutched from the valve stem means. The valve stem means 98 includes an outer stem portion 93 of generally D-shaped configuration provided by a fiat 94 and upon which the handle 30 is secured. It includes also a hollow inner larger diameter portion 96 having axial slots 98 therein and connected to the valve regulating shaft 46 by a pin 100 at the end of the shaft, the pin and slot connection permitting relative axial movement between the shaft and stem means. The stem means is constructed as an assembly including also a drive washer 102 tixedly secured to the inner end of the stem portion 96 as by peening 164 and having radially inwardly extending keys 106 extending into opposed slots 98.

The clutch means 92 includes the diametrically opposed forwardly extending drive ngers or projections 108 on the drive washer and the centralv generally annular portion 110 of a drive yoke 112. The portion 110 has apertures 113 adapted to receive projections 108 in the clutch engaged condition. rearwardly extending drive fingers 114 extending into oppositely disposed slots 116 in the rotor disc 28.

The drive yoke is rotatably mounted within the housing 78 as upon a tubular bearing element 120 iixedly secured within the smaller diameter forward extension 82 of the housing. The tube 12) has opposed outwardly extending front and

rear anges

122 and 124, the former of which abuts against the major portion of the front end of housing part 82v and the latter of which abuts against a shoulder 126-provided by counterboring at the region of the central opening inthe yoke 112.

In order to prevent undesired rotation of the yoke and valve disc after disengagement of the clutch means, breaking means in the form of a spring 130 is provided to fric- Y tionally restrain movement of the drive yoke, as described and claimed in the aforementioned Huff application, Serial No. 817,518. The spring 130 is disposed about the tubular bearing element 120 and between the annular part 110 of the drive disc and the vertical part 84 of the housing 78. The braking spring is constructed to havey a concavoconvex shape before assembly, thereby to prevent an effec- The drive yoke also has opposed tive frictional force for restraint of movement of the yoke.

The valve disc 28 is held against the valve body and thestern assembly is held in its axially outermost position by a spring 132, one end of which is seated against the outer surface of the valve disc and the other of which bears againstl the inside of the drive washer 102, the contact between the spring and drive, washer being through an annular spring guide 134. In the off positiony illustrated in FIG. `5, the stem assembly and valve handle are drivingly connected to the valve disc 2S through the drive washer and drive yoke through the engaged clutch means, the engagement being effected by disposition of the drive washer iingers 168 in the apertures 113 of the yoke 112. To declutch or disengage the drive washer from the drive yoke, the valve handle and stem are move-d inwardly against the force ofthe spring 132 thereby to disengage the drive projections 108 on the drive washer from the yoke, as shown in FG. 9; After such a disengagement, lthe valve and stem assembly can be turned independently of *he rotor disc valve 28 so that rotation of the handle turns only shaft 46 to adjust the temperature setting of the valve.

In accordance with the present invention, the valve is provided with improved locking means so that the valve handle cannot be turned until it has been pushed inwardly axially a predetermined angular distance. This locking means comprises a'pair of hat abutting surfaces on the valve stem means and housing. In the illustrated embodiment of the invention, the two flats are the hat on the housing and the at 142 on the stem. As indicated, see FEGS. 5 and 6, the flat 141B on the housing is provided by a radialiy inwardly extend-ing integral portion 144 of the housing and of which the flat 140 is -a chordal surface of the opening therein through which the stem 90 extends. The flat 142 on the stem is simply a milled flat effectively on the larger diameter portion .96 of the stem. Viewing particularlyvFIGS. 5 and 6, it will be noted that the surfaces 146 and 142 are in abutting relation so that the handle, the stem assembly and the Valve disc cannot be turned. To unlock the valve, the handle and stem assembly are pushed inwardly to the position of FIG. 7. The axial length of the flat 149' on the stem is about the thick ness, or slightly longer than the thickness of portion 144 of the housing, so that when the stem Vassembly is pushed inwardly to the position of FIG. 7 the stem assembly can be turned. Y

In accordance with a further feature of the invention, the valve is so arranged that the handle stem assembly cannot be declutched from the rotor valve disc 28 until after the former had been turned a predetermined angular extent, as of about 40 degrees. To accomplish this, cooperating abutment means are provided on the housing and stem assembly limiting axial movement ofthe stern assembly in the limited angular :region so that declntching cannot be effected. Referring now particularly to FIGS. 7 and 8, theV abutment means on the housing isconstituted by a downwardly and forwardly extending tongue 150 on the. bezel mount 71 and that on the stem by. an abutment or shoulder 152 in the smaller diameter portion 93 of the stem which is formed as by slotting aportion 154 of theV stem. The abutment 152, as shown in FIG. 7, is solocated that the tongue engages it and prevents inward movement of the stem assembly suicient to declutch the drive washer from the drive yoke. From FIG. 7 it wiil be noted that the tongue 150 is in engagement with abutment 152 and the drive fingers 168 remain in the apertures 113 in the drive yoke, thereby to drivingly couple the drive washer and the drive yoke.

In accordance with the present invention, the declutching is permitted after the stern assembly and valve disc having rotated a predetermined angular distance from the ot position. This is accomplished by making the slot 154 a chordal slot as shown in FIG. 8 so that, upon rotation of the stem, the. tonguev is moved radially outwardly to lie on a circular part of the stem. Thus, referring now to FIGS. 9 and 10, after the valve handle and stem assembly have been rotated so the tongue 150 is effectively moved from the slot 154, then the valve handle, stem assembly and drive washer 102 can be moved inwardly to declutch the drive washer from the drive yoke, as shown in FIG. 9. When declutched, the drive ngers 108 engage the rear surface of the drive washer and are no longer in effective driving engagement therewith.

It should be noted that the feature of preventing declutching of the handle and stem from the valve disc until the latter has been turned a predetermined extent can be utilized independently of the locking means. This can be accomplished by omitting the locking

ats

140 and 142 or only the portion 144 of which the fiat 140 is a part. When this change in construction is made, the valve handle and stem still have to be turned a predetermined extent before declutching can be effected.

Reviewing brieliy the operation of the valve, it will be assumed first that the valve is in its off position as illustrated in FIGS. v and 6. At this time, the tongue 150 is in the slot 154, the locking

flats

140 and 142 are in abutting relation to each other and drive washer 102 is fully coupled to the drive yoke 112, all as indicated in FIGS. 5 and 6.

In order to unlock the valve, the valve handle and stem assembly are pushed inwardly to the position illustrated in FIGS. 7 and 8. The inward movement is limited so that declutching cannot take place. However, the

ats

140 and 142 are moved out of abutting relationship and hat 140 bears against the circular outer portion of the stem portion 93 so that the valve handle stem assembly and valve disc can be rotated. Movement of the drive assembly suicient to permit declutching is prevented by engagement of tongue 150 against abutment 152, as shown in FIG. 7.

Once unlocked, the valve handle and parts connected thereto can be turned. During the turning operation, the tongue 150 is moved radially outwardly by the at surface of slot 154 and once the tongue moves out of the slot, see FIG. l0, the valve handle can be pushed inwardly to effect declutching by movement of the drive iin'gers 108 out of the apertures 113 in the drive yoke, see FIG. 9'. Once declutching is effected, the thermostat can be adjusted as desired wit-h the valve disc disposed anywhere in the range between the declutching point and the high or full on position of the valve element. Thereafter, the temperature adjustment can be effected as desired.

To return the valve to off position, the valve handle is turned back toward oit until the drive ngers 10S are moved into the apertures 113 by the action of the spring 132. Thereafter all the parts move in unison. It may be noted that :lingers 108 are movable into the apertures 113 when the valve is being turned toward off even in the angular region in which declutching is prevented by engagement of tongue 150 against abutment 152. This results from the fact that upon return movement toward oi position the tongue 150 can ride on the smaller diameter portion 93 of the stem with the aforesaid axial region, after which the stem can move axially outwardly to eiect clutching.

While the present invention has beeu described in connection with the details of illustrative embodiments, it should be understood that these details are not intended to be limitative of the invention, except insofar as set forth in the accompanying claims.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A locking type thermostatic gas valve, including in combination, a rotatable control element, a housing for said element, axially extending valve stem means extending into said housing and being rotatable and axially movable relative to said housing, means including normally engaged clutch means disengageable upon a certain axial movement of the stem means and interconnecting said stem means and element whereby said element can be rotated, means for locking said stem means against rotation including abutting ilat surfaces generally facing the axis of the stem means on the stem means and housing, said flats being movable out of abutting relation uponaxial movement of the stem means after which the latter can be rotated, and means requiring rotation of said stem means through a predetermined angle before said clutch means can be disengaged.

2. A locking type thermostatic gas valve, including in combination, a rotatable control element movable through a predetermined angular range between olf and full on positions, a housing for said element, axially extending valve stem meansy extending into said housing and being rotatable and axially movable relative to said housing, means including normally engaged clutch means disengageable upon a certain axial movement of the stem means and interconnecting said stem means and element whereby said element can be rotated, means for locking said stem means against rotation including abutting flat surfaces generally facing the axis of the stern means on the stem means and housing, said flats being movable out of abutting relation upon axial movement of the stem means after which the latter can be rotated, and angularly extending labutment means requiring rotation of said stem means through a predetermined angle substantially less than the angular extent of said range before said clutch means can be disengaged.

3. A locking type thermostatic gas valve, including in combination, a rotatable control element, a housing for said element, valve stem means extending into said housing and being rotatable and axially movable relative to said housing, means including normally engaged clutch means disengageable upon a certain axial movement of the stem means and interconnecting said stem means and element whereby said element can be rotated upon rotation of said stem means, means for locking said stem means against rotation including a at of short axial length on said stem means and a fiat on said housing abutting against the iiaton the stem means, said flats being movable out of abutting relation upon axial movement of the stem means after which the stem can be rotated, and means including opposed abutment structures on said stem and housing and one of which is radially movable and requiring rotation of said stem means through a predetermined angle before said clutch means can be disengaged.

4. A locking type thermostatic gas valve, including in combination, a rotatable control element, a housing for said element, valve stem means extending into said housing and being rotatable and axially movable relative to said housing, means including normally engaged clutch means disengageable upon predetermined axial movement of the stem means and interconnecting said stem means and element whereby said element can be rotated, means for locking said stem means against rotation including a at or" short axial length on said stem means and a flat on said housing abutting against the first flat, said flats being movable out of abutting relation upon axial movement of the stem means after which the latter can be rotated, and means including an abutment on said stem means and a resilient abutment on said housing engaging said first mentioned abutment on said housing requiring rotation of said stem means through a predetermined angle before said clutch means can be disengaged by said predetermined axial movement of said stem means.

5. A locking type thermostatic gas valve, including in combination, a rotatable control element, a housing for said element, valve stem means extending into said housing and being rotatable and axially movable relative to said housing, means including normally engaged clutch means disengageable upon predetermined axial movement of the stem means and interconnecting said stem means and element whereby said element can be rotated, means for locking said stem means against rotation including a flat of short axial length on said stem means and a iiat integral with said housing abutting against the first hat, said 'Hats being movable out of abutting relation upon axial movement of the stem means after which the latter can be rotated, and means including an abutment on said stem means and a resilient abutment on said housing engaging said first mentioned abutment on said housing requiring rotation of said stemmeans through apredetermined angle before said clutch means can be disengaged by said predetermined axial movement of said stem means.

6. A locking type thermostatic gas valve, including in combination, a rotatable control element, a housing for said element, valve stem means extending into said housing and being rotatable and axially movable relative to said housing, means including normally engaged clutch means disengageable upon predetermined axial move-y ment of the stem means and interconnecting said stem means and element whereby said element can be rotated, means for locking said stem means against rotation including a flat of short axial length on said stem means and a at on said housing abutting against the rst flat,

'said flats being movable out of abutting relation upon axial movement of the stem means after which the latter can be rotated, a bezel mount on said housing and means including an abutment of predetermined arcuate extent on said stem means and a resilient abutment integral with saidbezel mount engaging said first mentioned abutment on said housing requiring rotation of` said stem meansthrough a predetermined angle before said clutch means can be disengaged by said predetermined axial movement of said stem means.

7. A gas valve, including .in combination, a rotatable control element, a housing for said element, valvestem means extending into said housing and being rotatable and axially movable relative to said housing, means including normally engaged clutch means disengageable upon a certain axial movement of the stem means and interconnectin7 said stem means and element whereby said element can be rotated uponrotation of said stem means, and means including opposed abutment structures on saidv stem and housing and one of which is radially movable and requiring rotation of said stem meansV through a predetermined angle before sadtclutch means can be disengaged.

8. A gas valve, including in combination, a rotatable control element, a housing for said element, valve stem means extending into said housing and being rotatable and axially movable relative to said housing, means including normally engaged clutch means disengageable upon predetermined axial movement of the stem means and interconnecting said stem means and element where- 9. A gas valve, including in combination, a rotatable control element, a` housing for said element, valve stem Vmeans. extending into said housing and beingy rotatable and axiallytmovable relative to said housing,` means including normally engaged clutch means disengageable uponV predetermined axialA movement of the stem means and interconnecting said stem means and element whereby said element can be rotated, and means including an abutment on said stem means andV a radially movable resilient abut-ment on said housing engaging said first mentioned abutmentV on said housing requiring rotation oi said stem means through a predetermined angle before said clutch means can be disengaged by said predetermined axial movement of said stem means.

l0. A gas valve, including inV combination, a rotatable control element, a housing for Said element, valve stem means extending into saidv housing and being rotatable and axially movable relative to said housing, means including normally engaged clutch meansY disengageable upon predetermined axial movement ofthe stem means and interconnecting said stem means and element whereby said element can be rotated, a bezel mount on said housing, and means including an abutment of predetermined arcuate extent on said stem means and a resilient abutment integral with said bezel mount engaging said first mentioned abutment on said housing requiring rotation of said stem means through a predetermined angle before said clutch means can be disengaged by said predetermined axial movement of said stem means.

1l. A gas valve, including in combination, a rotatable control element movable betweeny off and on positions, a housing for said element, valve stem means extending intoY said housing and being rotatable and axially movable relative to said housing, means including normally engaged clutch means disengageable upon predetermined axial movement of said stem means and interconnecting the latter and the element whereby said element can be rotated, and means including cooperating abutmentsV on said stem means and housing, of which one is effectively radially resilient, requiring rotation of said stem means through a predetermined angular distance away from off before said lstern means can be moved axially to disengage said clutch means and permitting rotation` of the stern. means toward off position within said predetermined angular distance with the stemy means inv axial position to dis.- engage the clutch means. i

12. A gas valve, including in combination, a. rotatable gas ow controlling element movable between off and on positions, an adjustable thermostatic valve, manually operable means for rotating said element and adjusting said thermostatic valve, disengageable clutch means operatively connecting said manually operable means to said element, said manually operable means being rotatable to move said element and adjust said thermostatic valve, and

being axially movable to disengage said clutch means, and means including cooperating abutment structures on said valve and manually operable means, of which'oneis eectively radially resilient, requiring rotation of said means through a predetermined angular range when moving from oli toward on position before said means can be moved axially to disengage said clutch means and permitting movement of said means toward off position` in saidl range in axial position to disengage said clutch means.

13. A locking type thermostatic gas valve, including in combination, a rotatable control element movable between. olf and on positions, a housing for said element, valve stem means extending into said housing and. being rotatable and axially movable relative to said housing, means including normally engagedclutch means disengageable upon predetermined axial movementy of said stem means and interconnecting the latter and: the element' whereby saidv element canl be rotated, means for locking said stem means against rotation including a flat of short axial lengthy on saidv stem means and aat on said housing abutting against theiirst mentioned' at, said ats being movableV out of abutting relation upon axial movement of the,stemmeans after which the latterl can be ro` tated, and means including cooperating abutments on said stem means and housing, of which the one on the housing is effectivelyradially resilient, requiring rotation of said stem means throughv aVv predetermined angular distance away from oif before said stem means can be movedl axially to disengage said clutch means and' permitting rotation of the stem means toward oft position Within said predetermined angular distance with the stem means in axial position to disengage the clutch means.

References Cited in the tile of this patent UNITED STATES PATENTS 2,826,368 Winslow Mar. 11 1958;

FOREIGN PATENTS 27,5'16' Great Britainl T Dec. 13, i907" ',UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N0. 3,011,729 December 5, 1961 Richard O, Ives It s hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Coumn 6, line 63, column 7, lines 7 and 8, 29, 55, 69, and column 8, line 9, ior "housing", each occurrence, read stem means Signed and sealed this 26th day of February 1963.

(SEAL) Attest:

ESTON Go JOHNSON DAVID L. LADD Aitesting Officer Commissioner of Patents