US1831284A

US1831284A - Variable pitch propeller

Info

Publication number: US1831284A
Application number: US489655A
Authority: US
Inventors: Borchardt Stanley
Original assignee: Individual
Current assignee: Individual
Priority date: 1930-10-18
Filing date: 1930-10-18
Publication date: 1931-11-10
Anticipated expiration: 1948-11-10

Description

Nov. 10,1931. s. BORCHARDT v I 1,831,284

VARIABLE PITCH PROPELLER Filed Oct. 8, 1930 3 Sheets-Sheet l Q By Atlomey S. BORCZHARDT wmmam PITCH PRQPIS-W- Shets-Sheet 2 Filed fist. 18. 193- Nov. 10, 193i.

Nov, 10, 1931. s. BORCHARDT TECH PJEQPE' LIABLE P 3 Sheets-Sheet 3 Filed 06%.. 18, 1938 Inuenior Era/Zed?- Patented Nov. 10, 1931 UNITED STATES PATENT OFFIC STANLEY BORCHARDT, OF WAUWATOSA, WISCONSIN VARIABLE PITCH PROPELLER The present invention relates to a variable pitch propeller for aeroplanes and the like and has for its prime object to provlde a propeller in which the pitch of the blade may be changed at will in an easy and expeditious manner.

Another very important object of the invention resides in the provision of a variable pitch propeller of this nature which is simple in its construction, strong and durable, thoroughly efficient and reliable in use and operation, compact and convenient 1n its arrangement of parts, easy to assemble and d1sassemble, and otherwise well adapted to the purpose for which it is designed.

With the above and numerous other objects in view as will appear as the description proceeds, the invention resides in certain novel features of construction, and in the combination and arrangement of parts as will be hereinafter more fully described and claimed.

. In the drawings:

Figure 1 is a fragmentary slde elevation of an aeroplane showing a propeller structure associated therewith embodying the features of my invention,

Figure 2 is a longitudinal section through the propeller structure, I

Figure 3 is a sectional view taken substantially on the line 33 of Figure 2,

Figure 4 is a sectional View taken substantially on the line 44 of Figure 2,

Figure 5 is a detail view of the slidable block,

Figure 6 is a transverse section taken substantially on the line 66 of Figure 3,

Fi ure 7 is a transverse section taken substantially on the line 7-7 of Figure 3,

Figure 8 is a perspective view of one of the shoes, and

Figure 9 is a detail sectional view through a portion of the hub and showing how the disk which is connected to the propeller shank is held in a recess in the hub.

Referring to the drawings in detail it will be seen that the numeral 5 denotes a propeller shaft having an elongated squared portion 6 terminating in a reduced rounded terminal 7, the extremity of which is threaded as indicated at 8. A hub 9 is provided with a bore,

a portion of which fits snugly over the rounded terminal portion 7 and over an adjacent part of the squared portion 6.

At opposite points this hub is formed with radially ends of which are disposed disks 11 each being between 'a pair of washers 12. Shanks 14 extend outwardly from the centers of the disks 11 through the outer washer 12 and at their outer ends merge into of nuts 16 are disposed about each shank 14 and threaded inside the recesses 10. Cap nuts 17 are threaded in the outer ends of the recesses about the shanks 14 and form bearing therefor. The outer surfaces of these nuts 17 have hexagonal extensions 18 so that a wrench or the like may be used thereon.

The rear portion of the hub is provided with slots 19 leading to the disks 11 and cranks 20 are engaged withthe disks 11 and extend rearwardly through the slots 19.

An elongated block 21 has a longitudinally extending square bore to receive the squared portion 6 and to permit the block to rotate therewith and to be slidable thereon.

The rear end of the block 21 has an annular groove 22 with which is engaged a fork 23. A pull and push rod 24 is engaged with the fork 23 and is operable from a convenient point within the aeroplane as is clearly indicated in dotted lines in Figure 1 so that the block may be slid back and forth.

The forward portion of the block21 is of a square construction and has opposed faces formed with diagonal grooves 26 disposed obliquely with respect to each other. These grooves 26 are mortised as isindicated in Figure 6 and slidably receive shoes 27' having ribs 28 extending into the mortises of the groove. Studs 29 the shoes to receiye the rear ends of the cranks. Now when the block'is moved longitudinally of theshaft it will be readily appreciated that the shoes will be moved laterally with respect to the axis of the shaft thereby oppositely swinging the cra'nks and varying the pitches of the propellers 15.

A sectional housing 30 is formed with an inturned flange 31 at one end fitting in an annular groove 32 on the rear portion of the disposed recesses 10 inthe inner 55 propellers 15. A. pair 60 project outwardly from 90 hub 9 and at the rear end of the housing is an inturned flange 33 terminating circum acent the slidable block 21 to the rear of its squared forward end portion. A nut 34;- on the threaded terminal 8 holds the hub in place on the shaft and any suitable locking means such as a cotter pin or the like may be used in connection therewith.

It is thought that the construction, utility, operation and advantages of this invention will now be quite apparent to those skilled in this art without a more detailed description thereof.

The present embodiment of the invention has been described in considerable detail merely for the purposes of exemplification since in actual practice it attains the features of advantage enumerated as desirable in the statement of the invention and the above description.

It will be apparent that changes in the details of construction, and in the combination and arrangement of parts may be resorted to without-departing from the spirit or scope of the invention as hereinafter claimed or sacrificing any of its advantages.

Having thus described my invention, what I claim as new is:

In a variable pitch propeller construction, a hub having oppositely disposed recesses therein, disks in the inner ends of the recesses, shanks projecting outwardly from the disks and merging into propellers, means for rotatably holding the disks in the recesses, cranks extending radially from the disks, a shaft on which said hub is mounted, said shaft having a squared portion, a block slidable on the squared portion and having oppositely disposed fiat surfaces formed with diagonal grooves, shoes slidable in the grooves and connected with the cranks, and means for sliding the block.

In testimony whereof I affix my signature.

STANLEY BORCHARDT.