Sept. 18, 1934. 1'. M_ THQRSEN ' '_ . 1,9735783 STREAM LINE STERN POST BLOCK AND RUDDER ASSEMBLY Filed July so, 1932 2 Sheets-Sheet 1 Fig.1 21 22. 2s 40 4 9 2 d 3 as 18 V40 5 A} . 37 . a 36 :12'-—- A - v - - -‘—12 31 ML. " - -'-_ - ‘$40’ I ’ 32 ‘x 0 13 L- _ ’ -- - ~13 4 . \ ob 191535 18 17 B35 v I as‘ E 5 - 35 13.9.7 6 _ c3 B35 - ‘335 I ' , ‘335 I? 35 ~ Fig.T 8 ' as _ ‘33$ ' ' ' ‘(II . 1119.235 142$!’ _ . , 35 _ INVENTOR, I Theodo/ieM.Th0rse/1. BY . ' , . A TTORNEY. - ' Sept. 18, 1934. T. M. THORSEN 1,973,783 STREAM LINE‘: STERN POST BLOCK AND RUDDER ASSEMBITIY Filed July so. 1952 2 sheets-sheet . 2 INVENTOR, Theoc‘ZoreM. Thor-sen.‘ A TTORN . ‘ Patented Sept. 18, 1934 1,973,783 UNITED STATES ‘PATENT OFFlCE 1 STREAM LINE STERN-POST BLOCK AND . >RUDDER. ASSEMBLY '7 :Theodore M. Thorsen, Bellingham, Wash. Application July so, 1932, Serial No. 626,695 1 Claim. _'(01. lug-162) "" My invention‘relates to improvements in con ‘tion of ‘Fig. 1 with the propeller and rudder tra-propeller, stream-line, stern-post block and omitted drawn on a larger scale, Fig. 6 is a rudder assemblies for wooden hull boats and has horizontal section of Fig. 5 on theline 6+6, for an object to provide stream-line parts for Fig. 7 is a horizontal section of Fig. 5 on’the, ‘ 5 removable attachment to the stern-post and line 7-7, Fig. 8 is a horizontal section of 'Fig. \ml rudder of such boats to occupy the open space 5 on the line 8—'—8,-‘Fig. 9 is a horizontal section 'usually found between the stern-post and the of Fig. 5 on the line 9-9,>Fig. 10 is a transverse propeller thereof and to buildup the rudder into section of Fig. 1 on the line 10—10, drawn ‘on stream-line shape. ‘ a larger scale, as viewed from above the said . ' 10 - ‘Another object of my improvement is to pro 'line 10—10, Fig. 11 is a transverse section of 35; ;vide wooden stern-post blocks and ruddercheek the rudder, segregated, on the line 10-10 of Fig. 'pieces in order that they may be easily con 1 ‘as seen from below 'the' said line drawn on a formed to fair stream-line surfaces for [the stern larger scale, Fig. '12 is a transverse section of of each particular boat. Fig. 1 on the line 12—-12, (drawn on a larger ., ' 15 Other objects of my improvement will appear scale) Fig. 13 is a transverse section of Fig. 19. as the description proceeds. 1 on the line 13-—13 drawn on a larger scale, ‘In the hulls of Wooden boats it is the prac and Fig. 14 is a diagrammatic representation of tice to allow a considerable free space between the fairreverse curve along which the water is the stern post and the propeller blades, and also ~720to use a’ relatively thin metal plate of plane impelledblock and betweenmy stream-line my stern-post rudder above stream-line the pro- ‘75 shape for the rudder. The said free-space pro peller axis by the revolving propeller, and ‘the » vides for the occurrence of local whirls and eddies curved‘surfaces of the said block and rudder in the water at this place which oppose the pass between which the said current of Water passes. , ing flow of water impelled by the propeller rev- ’ Similar characters refer to similar parts ._ . ‘ 25 olutions. Also the plane surfaces of the rudder throughout. encourages the forming of local whirls in the -With more particular reference to the desig water next the surfaces thereof which hinder nated parts: A wooden boat hull 16 has the the rearward ?owof water» thereover, and in ‘keel 17, the stern-post 18, the skeg 19 with crease the turning radius of the'boat. rudder bearing 20 thereon, the rudder shaft ., ' 30 - Because of the individual characteristics of the _'21, the rudder shaft bearing 22, the rudder shaft '85 hullsof wooden boats the dimensions and shapes coupling 23, the rudder 24, the rudder stem of the ‘parts thereof about which this inven 28, the rudder stem shank 01.28, the rudder - tion is concerned vary to a degree making it un gudgeon 29, the propeller shaft 30, the propeller practical to provide metal castings for the pieces shaft 'outbearing 31, the propeller hub 32, the ., > 35 which my improvement‘ require because nearly propeller blades 33 and 1133 and the stream-line ‘90 - each boat would require special patterns for these propeller shaft nut 34. ‘ pieces thus adding considerably to the cost of The rudder 24, which in boats of this char the improvement. ~ acter usually is a relatively thin plate of iron In practice I have found that suitable pieces vor ‘steel, preferably for my purpose is cleft at "4740 made of wood can be especially shaped for each 26 in its ‘counterbalance edge in line with‘ the "95 ‘boat at ‘a small expense and fastened in place axis‘of the propeller shaft, and the said edge ' in'a manner insuring a reasonable term of serv above the cleft is bent outward as at 25 inv one ice. “ - ~ ~ - > ' direction while the edge 27 below the cleft at - I attain these and other objects of my im 26 is bent outward in the‘ other ‘direction, and. 45 provement with devicesillustrated in the two theven'ds of the bent over parts at: the cleft “100 ‘ sheets of accompanying drawings in which Fig are bent at a larger angle than the ends thereof ure 1 is a side elevation of a portion of the stern at the top and bottom of the rudder as shown of a wooden‘ boat hull,‘ the remainder thereof in Figs. 2‘ and 4. _ ' being broken‘ away, showing my stream-line - > '50 blocks in place thereon and also the cheek pieces the'It'is stern-post, the custom'to of those make boats the with aft’ which surface this"1°5 of for the rudder thereof in place thereon, Fig. 2 invention is concerned, straight transversely; . is a top-plan view of the rudder before my cheek thus failing to complete the stream-line shape pieces are attached thereto, Fig. 3 isa side eleva Yof the hull at the stern thereof, and providing tion of Fig.2, Fig. 41s an elevation view of the "a place into which the water may not quickly , . I‘ ~55 forward end of the rudden'Fig- 5 iSa real‘ eleva ‘enter as the boat moves forward, thus com- "110 1,973,788 pelling a quantity of water to- follow along with vertical opposite the propeller but follows the the boat aft of the stern-post while it is being shape of the hull and curves rearward above revolved by the main body of the water past the same, and my stern-post block follows the which it is being carried and more especially direction of the aft surface of the stern post 18 by those parts of the main body of the water and consists of the part 935 below the shaft out 80 which are deflected to pass between the stern bearing 31, the hub part 36 around the said out post and the rudder as impelled by the revolv bearing, the central part 35 above the hub part ing propeller blades. _ _ n . I . and the top part 3'7 above the propeller. For Thestern-post?“stream-line‘block 3'5, Q35 and. ‘(convenience of construetion the top part 3'7 is 10 the stream-line'rudder 40, i140, H40 and'b40, f40 made separately from the other parts to which 85 provide stream-line surfaces between which the“ ‘it is‘joined opposite the top of the propeller. said de?ected currents of water may ?ow in ‘fair,’ _ The peak a3’? of the top part of the block is curves unhindered by the eddying waters being nearly medial thereof and this part of my block carried along with the aftgpartsiofithesaid is relatively. .thin making the fastening thereof 15 boats when built as usual. 1 - tov the stern post easily attained by the nails The diagrammatic drawingshown in Fig. 14 .39 driven through the‘ block and into the stern will aid in explaining the" way in’which the" ‘post against which it is placed. The lower parts desired stream-line surfaces are-Tdet'ermined. ‘In of. the block which are opposite the propeller are Fig. 14 o—o is the center line of the boat being thicker and are fastened to the stern-post by 20 improved by the addition of my devices." The the'staples 38 alone. 95 ,line :c—-a: ,is_,drawn_through. the center of the The peak 035 of the-part 35at the top there propeller blades at‘right angles with 0-0. , The of is near the center but it curves toward the "line 'y—y is'drawn through the rudder axis at right hand,“ as’. onev faces forward, and vjoins ‘right angles with the line o_—o. Two positions the hub part 36 near the right-hand side of of ajpropeller 'blade'above the axisthereof are the block. The peak ‘e35 ofi the partvd35 at the 100 ‘given the one in solid lines at, 33 is,_in rotation, lower end of the block is, near the middle of the "in front, of the propeller. axis and the one in block aty-its bottom and curves toward the left dotted lines’ at 33'_ is,’ in rotation, behind the to join with the hub part 36 near the'left side ‘said axis.