US1364196A

US1364196A - Apparatus for making propellers

Info

Publication number: US1364196A
Application number: US234960A
Authority: US
Inventors: Heath Spencer
Original assignee: Individual
Current assignee: Individual
Priority date: 1918-05-16
Filing date: 1918-05-16
Publication date: 1921-01-04
Anticipated expiration: 1938-01-04

Description

S. HEATH.

APPARATUS FOR MAKING PROPELLERS. APPLICATION FILED MAY 16, 1918.

1 ,364, 1 96. Patented Jan. 4, 1921.

Pitt TENT l FICE.

APPARATUS FOR MAKING PBOPELLERS.

Application filed May 16, 1918.

To all whom 2'23 may concern:

Be it known that I, Srnnonn I'IEATI-I, a citizen of the United Eltates, residing at Baltimore, State of Maryland, have invented new and useful Improvements in Apparatus for lllaking Propellers, of which the following is a specification.

My inventionrelates to the making of propellers, particularly the wooden propellers designed and constructed for aerial propulsion, and it relates especially to apparatus for use in outlining a propeller blank or propeller or the step of outlining in the gen oral apparatus and method of making such propellers.

Owing to the nature of the material of which these propellers are constructed, it is diificult to successfully cut the various parts to the exact desired shape, and it is also ditlicult to properly hold the work while being operated upon. A suitable blank is first made, preferably by gluing together laminations of wood or other suitable material. These laminations are of the general shape of the propeller, and the blank so constructed has roughly the general form desired for the finished article, which is produced by cutting the blank down to the exact outline and shape of blades and hub desired.

@n account of the greater strength of the various parts of the blank, while in the rough I prefer to cut the work to the exact outline before the faces of the blades are worked down to the final shape, thereby reducing the chance of splitting or breaking to a minimum, although my apparatus and method are operative in another sequence of operations.

The invention resides principally in the mounting and holding of the work in such a manner that the propeller as a whole will be accurately centered and the two or more blades will be correctly outlined so that the structure as a whole will embody that peculiar relation of the parts, that nicety of balance, and that equality oi function which are necessary for the successful operation of an aerial propeller.

Apparatus for carrying the invention into effect is illustrated in the accompanying drawings, in which Figure l is a perspective view of apparatus for outlining a propeller or propeller blank, said apparatus including the pattern Specification of Letters Patent.

Patented Jan. 4:, 1921.

Serial No. 234,960.

and propeller or blank, a three-bladed propeller being shown;

Fig. 2 is an edge View of the pattern and propeller blank on an enlarged scale, the parts including the end supporting and fastening devices being shown displaced from their operative positions;

Fig. 3 is a sectional view on a greatly enlarged scale, showing the hub centering and mounting portion of the pattern and blank;

Fig. 4 is an enlarged View of one of the supporting and fastening devices; and

Fig. 5 is a similar View of a modified form ot' said suporting and fastening device.

Referring to the drawings, 10 indicates the pattern which is preferably of wood or other suitable material and which has the contour which it is desired to give to the finished propeller. The pattern is adapted to rest upon a table ll provided with cu ters 12 adapted to outline the edge of the propeller or the propeller blank in accordance with the pattern, immediately below the cutters being provided a smooth nonrotating follower member 13 for engagement with the pattern.

Each pattern is provided with a hub portion 14 and a plurality of blade portions 15, three of which latter are shown in the drawings, although any other desired number may be provided according to the style of propeller under construction.

At the hub portion, the pattern 10 is pr0- vided with means for centering the work upon the pattern, this means being shown as a pin 16 mounted in a suitable socket l7 and extending upwardly the proper distance to permit of the application of nut 18 or other fastening means alter the work has been put in place. Surrounding the pin 16 is preferably employed a sleeve 19 adapted to fit snugly within the central bore of the hub portion 20 of the propeller or propeller blank 21. This central perforation in the propeller blank accurately centers the blank upon the pattern, and as the pattern has been accurately cut to provide the exact length and shape of each blade, the propeller will be evenly balanced for accurate revolution.

Each blade portion 22 of the propeller blank is supported upon the pattern by a suitable combined holding and supporting device 23, one form of which is shown in Figs. 2 and 4:. This form consists of a socket or bushing 24 suitably mounted near the outer end of each of the blade portions of the pattern, and the under surface of the pattern is chambered at 25 beneath this bushing. A sleeve 26} has a sliding engagement with the bushing and extends through a perforation in the pattern. The upper end of this sleeve 26 is provided with sharpened projections or tines 27 for engagement with the propeller blank and the lower end of said sleeve is split as shown at 28 for a distunes from the lower end. The extreme lower end the sleeve 26 is provided with inclined s rfaces which are engaged by a locking member 29 having at its upper end a threaded portion 30 to be screwed into the propeller blank, and at its lower end a handle or other turning means 31 and a conical surface 32 for engagement with the inclined surface of the sleeve 26.

In the production of a propeller, the blank is preferably built up of laminations shown in Figs. 2 to 5, these laminations overlapping to provide the general form of the propeller. A central aperture is provided, and the blank is centered upon the pattern by slipping the blank upon the sleeve 19 which snugly fits the central perforation and accurately centers the blank upon the pattern. After securing the blank in place by means of nut 18 or any other suitable device, the blade portions 22 are supported and secures after they have been brought into proper position over the blas portions of the pattern, by slipping the looking sleeve 26 and pin 29 up through the socket 24 until the threaded portion of the locking pin 30 engages the blank when it may be screwed into the blank by turning the end 81. The parts are so proportioned that when the threaded portion 86 of the locking pin has taken a firm hold of the blank, the cone surface 32 engages the lower inclined or conical surface of split sleeve 26, when continued upward movement of the locking pin 29 spreads the split portion of the sleeve 26 sufficiently to securely lock the entire device. At the same time that this upward locking pressure of the cone surface is exerted, the sleeve 26 is pushed upward to a certain extent to cause the tines 27 also to engage the blank. The combined action is therefore that the sleeve 26 is prevented from turning by its engagement with the blank and is then looked securely in the adjusted position. locking are therefore substantially automatic, and the blade portion of the blank is both supported and held in the proper position.

In place of the automatic adjusting and locking device shown in Fig. 4:, I may employ a more simple arrangement such as shown in Fig. 5, in which a locking pin 33 is mounted in the socket 24 and is provided The adjustment and incense with a threaded portion 34 at its upper end. This pin is secured in its adjusted position by means of a set-screw 35.

After the propeller has been securely mounted on the pattern, as above indicated, the combination as a whole may be slid around and manipulated upon the table 11 so as to bring all of the pattern into engage ment with the smooth portion 13 of the cutters, in order to accurately cut the edge or outline of all parts of the blank. After the blank has been treated in this way, it is removed from the pattern and the faces of the hub and blade portions are finished in any suitable or known manner, thus completing the method of construction.

An important function of the described method of outlining aeroplane propellers of two, three, four, or any number of blades is that by thedescribed means, after having bored the center hole in the rough propeller block thereby establishing its precise geometrical center, it is possible by means of an accurately made follower pattern to out line the blades with perfect geometric accuracy as regards not only their uniformity of size and shape but the precise and accurate space of the blades equidistant from each other. This eliminates the very tedious and expensive process of trameling the blades for spacing them and for accurately locating outlining patterns for marking off their contour before reducing them to size by hand-cutting or other method previously employed.

A further important feature relates to the spur holders near the extremities of the blades. These are so made that at the same time the spur is inserted in the propeller block or immediately thereafter, the height of the spur is adjusted to accommodate the correct relation between the outline blank and the propeller block. Without this provision for vertical adjustment the outline blank would in most cases be distorted either by drawing its ends up toward the propeller block or by pushing them away from it. Any distortion of the outline blank in this measure would prevent the said blank from lying flat upon the table 11 of the machine and permit it to rock to and from the cutters 12 in such a way as to prevent accurate and uniform work.

While I have shown and described one form of apparatus for carrying my invention into efiect, it is understood that many modifications may be made without departing from the invention, and all such modifications, ll consider within the scope and purview of the invention and aim to cover by the appended claims.

I claim 1. In apparatus for making propellers, an outline pattern having the peripheral contour desired for the propeller, means carried neeanee by said pattern for centering a propeller or propeller blank upon said pattern comprising a shaft adapted to extend through a central hole in the hub portion of the propeller blank and having fastening means for clamping said propeller blank on said pattern, a combined supporting and holding device carried by said pattern for supporting in fixed position each blade portion of the work upon the pattern, a table upon which said pattern rests and is capable 01" sliding, a cutter on said table, and rotatably mounted on an axis parallel to the central bore of the propeller blank for cutting the edge of the work, and a smooth surface associated with said cutter for contact with said pattern.

2. ln apparatus for making propellers, an outline pattern having the peripheral contour desired for the propeller, a centering pin uprising from the central portion of said pattern to extend through the center of the hub portion of a propeller or propel le'r blank, means carried by said pattern for securing said propeller or propeller blank upon said pin and on said pattern, and an adjustable support carried by and extending upwardly from said pattern to engage and hold each blade portion of said propeller or propeller blank.

in apparatus for making propellers, an outline pattern having the peripheral contour desired for the propeller, centering pin carried by and uprising from the central portion of said pattern to engage and center the hub portion of a propeller or propeller blank, a sleeve surrounding said pin and adapted to engage the bore of the hub portion of said propeller or propeller blank, means carried by said pattern for securing said propeller or propeller blank in position upon said sleeve and on said pattern, an adjustable support carried by and extending upwardly from said pattern to engage and hold each blade portion of said propeller or propeller blank, and a cutter member adapted to trim the edges of the propeller blank, said cutter being rotatabl mounted on an axis parallel to the bore of said propeller blank.

l. in apparatus for making propellers, an outline pattern having the contour desired for the propeller, means for centering a propeller or propeller blank upon said pat tern comprising a shaft adapted to extend through a central. hole in the hub portion of the propeller blank and having fastening means for clamping said propeller blank on said pattern, and an adjustable support extending upwardly from said pattern and having means for engaging and holding the blade portion of the work at the proper height above said pattern.

5. ln apparatus for making propellers, an outline pattern having the contour desired for the propeller, an adjustable holding support for the blade portion of the work comprising a socket mounted upon said pattern, a split sleeve slidably mounted in said socket and having roughened engaging means at its upper end, and a locking member having an edged portion in engagement with the split part of said sleeve and a threaded end for engagement with the work.

6. ln apparatus for making propellers, an outline pattern having the contour desired for the propeller, an adjustable holding sup port for the blade portion of the work comprising a socket mounted upon said pattern, a split sleeve mounted in said socket and having a conical inner surface at the split portion, and a locking member having a conical surface engaging said conical portion of the sleeve and a screw-threaded upper end for engagement with the work, and means for turning said locking member to draw the sleeve into engagement with the wdrk and to lock said sleeve in said socket.

In testimony whereof I have hereunto set my hand.

SPENCER HEATH.