US2048529A - Plasterer's center ribbed aluminum darby - Google Patents

Description

July 21, 1936. A. s. WILLIAMS 2,048,529

PLASTERERS CENTER RIBBED ALUMINUM DARBY Filed Oct. 17, 1955 mi E' I Am a MW/ mf Patented July 21. 1936 1 'UNITED STATE/S,

PLASTERERS CENTER RIBED, UMINUM" I g This invention has general reference to improvements in plasterers darbies; and it consists, essentially, in the novel and peculiar combination of parts and details of construction, as '5 hereinafter first fully set forth and described, and

thenpointedout in the claims.

I The principal object of this invention is to provide a darby wherein the blade of the darby consists of a flat strip of aluminum that is re- 10 inforced by a wood rib arranged on the aluminum strip along the longitudinal center line thereof. v

Another object of the invention relates to a metallic reinforcement for the wood rib torex- 15 tend the full length thereof. v a

A further object of the invention resides in the manner of mounting the handle; and fin of the darby on thewood rib. v

A still further object of the'invention relates 2Q to the roughening or fluting of the longitudinal edges of the aluminum blade of the darby to provide a proper key for the finishing coat of plaster.

With the foregoing and other objects in view 25 which will appear as the description proceeds, it is. to be understood that changes in the precise embodiment of the invention herein disclosed may be-made within the scope of what is claimed without departing from the spirit of the inven- 30 tion.

In the accompanying drawing the preferred form of the invention has been shown.

In said drawing: Figure 1 is a perspective view of the improved 35 plasterers darby,

Figure 2 is a cross-sectional view thereof taken on line 2-2, Figure 1,

Figure 3 is a cross-sectional view thereof taken on line 3-3, Figure 1, 40 Figure 4 is a perspective view of a portion of one edge of the darby blade showing the transverse serrations or grooves thereon, and

Figure 5 is an end elevational view showing the longitudinal grooves or flutings on the underface of the blade.

Referring again to the drawing, the darby shown in its entirety in Figure 1, comprises the usual blade H) which in this case is preferably made of a strip of aluminum or other suitable 50 preferably non-ferrous metal having a thickness of A a width of 3%" and a length of 40". These dimensions have been found most satisfactory for general use of a darby though it is obvious that the blade thereof may assume 55 other dimensions if so desired. The metallic blade I0. is fiat throughout itsentire extent'and of rectangular formation with the longitudinal edges H and [2 parallel.

jDisp'osedon one side l3 of the blade l along the, longitudinal center thereof is a wood rib l4,

the 'ends'of which terminate short of the transverse edges of the bladev It] as clearly shownin Figure 1. Encasing the wood rib [4 which preferably is of square. cross-section" is a metallic channel reinforcement li that is adapted to snuel0 ly receive the wood'rib M. .The legs or sides I6 of the channel. [5 are of a'length less than the height of the wood rib so that the same are spaceda slight distance from the surface l3 o'f-the'blade ii], for a 'purposeto be hereinafter described. The channel? I5 is preferably made of aluminum or' otherlnon-ferrous metal, of rolled or cast stock andiof not less than thickness throughout.

- 'The blade' I, wood rib. l4; and metallic chanher I'5'are secured rigidly together by the spaced screws or rivets I8.

. Adjacent one end: of thejblade l0 is arranged an upright wood" handle 20'that. is preferably seated on the channel l5 and rigidly secured in place: byfthe' screw '21, that passes upwardly thro'iighthe fbl'ade I 0, wood rib '14; channel l5 into threaded engagementwitha threaded metallic bushing 22 provided axially within" the handle '20 all as clearly shown in Figure3. If desired the wood handle 20 may be replaced with a metallic handle in which case the bushing 22 may be replaced with a threaded bore within the handle.

Also adjacent the other end of the blade I0 is arranged a fin 25 of wood or metal seated on the channel I5 and rigidly secured in place in the same manner as the handle 20 is secured in place.

The rivets or screws l8 and the screws 2| are provided with counter-sunk heads that are flush With the under surface of the blade l0, and are also made of a non-ferrous metal to obviate any corrosion taking place.

The longitudinal edges II and I2 of the blade 745 ID are roughened, vertically serrated or grooved as indicated by the reference character 21 so as to provide when the darby is used on. the first brown coat of mortar a'proper key thereon for the application of the second or white coat of plaster. In Figure 4, the vertical'grooves 21' along the edges of the darby blade are formed by pressing the same in with a suitable tool with a consequent deformation of the metal at the ends of the grooves and edges of the darby as at "28 As these raised portions 28 wear off in use there' will still be left the grooves 21' to provide the proper key. If desired the roughened edge or vertical serrations may be dispensed with entirely and small grooves or flutes 29, see Figure pro vided on the under face of the blade ashort distance from each of the edges II and I2; This the first plaster coat.

is anothermethod for accomplishingthe same purpose for the provision of' the proper key on I I desire it understood however each of the above indicated keying means are not strictly necessary to the operation of the derby) as the same may in the'hands of a' skillful plasterer be used successfully; In some cases the edges of a the blade I]! mayjbe supplied trueeandismooth' in the manufacture thereof and the sameioughened by the plastererf'if s'o'desired, by merely hacking the edges with .the plasterers pointing trowel whichhe has at hand at all times. This will in no v way affect the durability of thefdarby.

'f The invention as above'set forth has theadvantageover a wood darby or a wood darby pro lvided withrmetlallic edges in that by virtue of the aluminum blade employed thesam'e will not hang to the mortar with'the consequent pulling off of the mortar; the aluminum blade sliding over the rmortar with greatergease as well'as acting to fill fin all-'unevenfportions. 'Anotheradvantage of the invention relates to the fact that the'darby may be manipulated without ajsprinklin'g 'of wa t'er on the plaster or mortar as is done beforeusing a'wood darby; the useof water acting to 'd'estroy'the hardness of the'surface 'of'the plaster or Imortarlto someextenti Therdarby of this invention retainsat all times'apermanent straighthess when applied against the plaster in the natrural position by being held by the handle and fin.

. Atthe same time it can be'fiexed by the application of" the proper pressure to the handle and Vfin. "It'is' evident that because the walls It of the channel l5 are. clear of the upperjsurface 13 of th'elblade 10, the reinforced rib "construction will permitof, this flexing of the darby. I 'Inasmuch as the handle and fin are secured to the wood rib and channel there is no, dangerv of the same pulling away or turningon the compara- 7 means for rigidly --securing said fblade; crib and handling means together.

Having thus set forth and disclosed the nature of thisinvention, what is claimed is: V

1. A darby comprising a single elongated fla blade of non-ferrous metal, a rib extending substantially the full length of said blade terminat- 5 ing short of the ends thereof and positioned thereon along the longitudinal. axis 7 thereof, spaced handling means arranged on the rib adjacent the ends thereof, and? comn ongf astening 12. A darby comprising an elongated flat blade of non-ferrous'metal, a wood'rib' extending sub' 'stantially thefull'length of said bladeand arranged on the longitudinal axis thereof, reinforce ing means for said wood rib, spaced handling means arranged von the rib adjacent, th'e'ends thereof; and common'fastening means for rigidly securing said blade, wood rib, reinforcing and handling means togethern 3. In the-"darby as; set man atem 2; said,

reinforcing means comprising a' non-ferrous me-V tallic channel snug'l'y embracing said wood; rib 7 over itsentire length the legs 'ofsaidchannel being of {a length less thanthe height-ofsaid rib and spaced fromthe upper face ofsaid blade and separate spaced fastening means for rigidly" V securing together said blade, wood rib and chan nel reinforcement.-

" 4: In the 'darby asset forth 'in -cl airn' 2,-said spaced handling: means} comprising ahandle at one end of said darby and an elongated mi-at the otheriend thereof: I o

' '5. In'the darby as' set'forth in 'claimfl, the a longitudinal edges of said'bladebeing roughened V or serratedwfl' a i 6. In the-'darby as set rqr'mm claim 2, the V longitudinal edges of said blade being roughened or serrated. '7 5 Y f I 7; In thedarbyras setlforth in claim 1', anda plurality of longitudinal grooves or flutes fprovidedon the'under face of said bladeadjacent' j the longitudinal edges thereof.* q I V 8. In the darby as set forth in 'claim2,"and' grooves or; flutes provided' on V the under face' of said blade adjacent the longitudinal 'edgesithere

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