US1309454A - Parker richardson bradley - Google Patents

Description

METHOD 0F DoPf'NG AIRCRAFT. APPLICAUON FILED DEC. 22. 1917.

1,309,454, A Patented my 8, 1919.

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UNITED srnrns Pn'rnnr ernten@ PARKER RICHARDSON BRADLEY, OF EAST ORANGE, NEW JERSEY, ASSG'NOR T0 AIRCRAFT FIREPROOFING CORPORATION, OF NUTLEY, NEW JERSEY, A. COPU P ORATION OF NEW JERSEY.

'METHOD 0F DOPING AIRCRAFT.

Specification of Letters Patent.

Patented July 55,

Application tiled December 22, 1917. Serial No. 208,448.

To 1H wlw/n, t muy concern.'

Bc it known that I, Pannen R. B'ixnLnY, a citizen of thelhited States, and a resident of East Orange, in the vcountyiof Essex and btate of New Jersey, have invented a new and Improved Method of'Doping Ain craft, ot' which the following is a full, clear, and exact description-.

This invention relates to an improved method Vot' applying dope`or tireproof coating liquid to wing and other surfaces-of flying machines. and the invention has for its general objects to improve the system of earrying on this work 'so as to'bc economical, expeditious, eliminate waste and at tlie same time prevent danger of poisoning the employees from noxious fumes or creating a nuisance to the neighborhoodin which the plant. is established.l

lVhile an aeroplane is very large and bulky, measuring fortyto seventy feet and more .from tip to tip of wings, `it is -made up ot' a number of comparatively small sections jointed one :to the other with metal attachmente.y These sections areconstrncted of small pieces of wood as a framework over which is stretched linen or other cloth. Ow-A ing togthe shape of the frame it is not possible to stretch the cloth on tightly, thereforea ydope or waterproof coating is used, which as it dries will contract and draw up the liueix cloth to a tight, drumlike surface.

lt is customary to apply anumber of coat-' ings ofdope, say six to ten coats, and when all are dry to apply one or more coatings of spar varnish, which stands the weather better than any` dope. 4

lleretofore all this ,work has been done by hapdemployingskilled painters, and

.each coating is dried in the workrooln, and

takes tive or more hours, depending on the During -the drying, poisonous gases or vapors are given oft' in great volume, which, if alarge business is done, invariably causes sickness among the einployees, and sometimes results in the death ot' yemployeev besides being an. offense to the entire neighborhood; and the aeroplane takes about `ten days for its completion.

The present methods when followed on a large scale have several serious objections, such as poisoning the employees; creating a nuisance in the neighborhood; labor dipping frames, submergiiig the frames and aeroplane parts in a tank containing a dope which is sufficiently liquid to permitof dipping, raising the frames and dipped parts out of the tank, and then conducting them through an air-tight drying chamber w 'ih has suitable means for drawing oft and condensing the vapor and fumes. Before the sections of the wing are dipped each is provided with a drain opening at the bottom so as to permity the surplus dope to drain olf the inner surface of the fabric.

For a more complete understaiiding` of the invention reference is to be had to the following description and claims taken in connectionwith the accompanying drawings, in whichsimilar characters of reference indicate corresponding parts in all the views, and in which Figure i is a plan `View of one of the cars on which the dipped parts hang dering ine dipping and drying operation; i

Fig. 2 is a vertical section showing a pire rality of wing sections suspended on car and submerged in a deep tank The carriage B on which the wing sections are supported while being (lipped or while drying, travels on rails 7 from the dippingl 'station to the drying room, and from the latter to a point of discharge. ln' the dipping room are track rails l2 on which is a tank 13 into which the wing sections are dipped.

The ear B comprises a horizontal car frame 15 having trolley wheels iti b which the car is suspended on the track rails. @n the car frame is an elevating fi une lll yembodying corner uprights Nrwhich have rack teeth 1S. rl`lie`seteeth mesh with pinions .19 on horizontal cross shafts 20, which latter are connected by gears E21 with a longitudinal shaft 22. On the shaft "2 is a .16 will be held raised.

'tank containingthe dope.

4is the lightestweight t'or sockets.

largegear wheel :23 whiehnieshes with a pinion il on a transverse operating shat't 25 that carries a brake wheel '.'i with which cngages a brake band or equivalent means 27 which normally is frictionally engaged with the brakewheel so that the elevatin frame ()n the en( ot the shat't 25 is a clutch element 28 which is adapted toA engage with a clutch element 2t on a power shat't 30 located in the tankroom 2. The shaft il() is moved longitudiually to engage oi'disengage the clutch elements and 2S) when a car B is in proper position over the dipping tank. 'hen so positioned the brake band ,slightly released, so that the elevating t'ranie can be lowered to subiiierge the parts to be coated in the tank. and after theI lapse o'l a proper Vpei'iod ot time the power may be applied to the sha t't` either by hand or motorrto gradually raise the elevating trame and i'emove the coated parts l'rom the tank. lVhen Ithe elevating frame lo -is t'ully raised the brake device is set and the clutch element .29 disengaged t'rom the clutch element 28, so that the car with the coated parts thereon can he moved into the' oven. Dipping trames ill are employed to support the aeroplane wing sections and the other parts that are to be coated, these frames being attached by suitable connecting devices 32 to the elevating frame 16. rlhe means t'or attaching the aeroplane parts to the dipping trames are not shown, as any suitable, devices mayy be employed.

The. operation is as l'ollows:

'lhe dipping frame loaded with-aeroplane parts is placed in dipping'rooiii over the 'l`he power is started andthe dipping trame lowers the aeroplane parts into the tank at the greatest speed possible without splashing and they Aremain a l'ew moments; they are then raised very slowly indeed. completely out of tank and'allowed to drain a t'ew moments. rI`he total time consumed in applying one coat to an aeroplane. should lie about fifteen ininutes, divided as follows: one minute to eriter; three minutes to soak: six minutes to withdraw: tlve minutes to drain. The door tothe drying room 4is then opened and the car with the dipping trame and contents enters oven and the dooi' is closed. llt may tak a longer or a shorter period ol' time.

The lowest. parts of the aeroplane sections are to have drain holes .r bored through the wood trames, with metal sockets; aluminum These sockets prevent the weakening of the Jframe. The first coat ot' dope soaks through, coating the back ot' the fabri' as nuich as the tace and thereby obtaining a' t'ar superior ett'ecty thanl is obtained ,by brushing on the dope by hand or any other way. `Otl course the dope inside the aeroplane frames must be A p moved into drying oven and the vapors arising from the dry'ing process are condensed into solvents. lt requires about an hour to dry. this period will be iiioi'e or less according to the boiling points otI the solvents used and the heat of the drying ovens. 'ith air locks and a partial vacuum in the drying ovens a solvent may be used ot a very low boiling point. whereas when the work is done by hand, as is now the invariable custom. 'in the open air ot' the ordinary work-v shop. a lai'ge proportion of high boiling point solvent must be used to oll'sct the daiiipness in the air. This is a very iiiipoi'- tanti point. as low boiling solvents are usually t'ai' cheaper than the high boiling solvents .ind are not ol" such an obnoxious odoi' and are not as poisonous.

'hen the surface ot' thecloth on wings is dope-tight` say after first or second dipping. the drain holes should be plugged with corks or plugs. as no further drainage is needed, as the dope will have ceased soaking through thil cloth. titer the desired number of coatings ot' dope have been applied. the dope tanh is replaced willi a tank ol' spar vai'- nish and the door between the drying oven aml dipping i'ooiii is opened so the temperatiii'e ol the dipping room is raised to ai'oiiiid Utl "ahrenheit, more orI less, and the doped t'rames are dipped into the spar varnish. The varnish and room must be warm and the dipping is done very slowly. taking at least twenty minutes and the ordinary commercial spar varnish may be thinned down with turpentine. A\tter the coating ot' spar 'an nish has been applied the. car is moved into the drying room a-iid dried two hours and then moved into open air of workshop.

rlhe solvents are condensed but are drawn ofi' into separat/e barrels from those containing dope solvents. 'lhc varnish requires six lioui's to dry sutlicieiitly so the wings may be removed Vt'rom dipping trame and hung up in storage lot'ts.

llaving thus described my invention. l claim as new and desire to secure by'Lette'rs lateut l. The method of doping a hollow aeroplane wing section having at'abric-covered lrame with drain openings in thetrame, which consists in dippingthe said section in a coating material long enough to permit the coating material to penetrate through the pores of the fabric, draining the surplus material from the outer and inner surfaces of the wing section, drying the coating inateriah and repeating the dippit'if, draining and drying steps a plurality of times.

2. The method ot' doping a hollow aeroi plane wing provided with drain nieanst'or tlw ('lxzmlbei of the wing. which consista in supportnngr lw wlng 1n position with the drum imams :it rlw'lmttom and dipping the wingr thus supported in n mmtinglf liquid, 1'0- nlovingf the win,f r from the liquid, Supporting' tlm wingr whereby the sui-plus llqxud can drip Oil" the outer surface of the wing and drain 'ont die drain means of the vlnnnbm'. closing' the drain nionnfs, und repeating' the dipping' and draining operation, wlwi'oby only the outer surfaces of the wing will receive :mother coating?.

PARKER RICHARDSON BRADLEY.

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