US3420177A

US3420177A - Time delay mechanism

Info

Publication number: US3420177A
Application number: US502749A
Authority: US
Inventors: Frank H Swaim
Original assignee: US Department of Navy
Current assignee: US Department of Navy
Priority date: 1965-10-22
Filing date: 1965-10-22
Publication date: 1969-01-07
Anticipated expiration: 1986-01-07

Description

Jan. 7, 1969 F. H. swAlM TIME DELAY MECHANISM l of 2 Sheet Filed Oct. 22, 1965 H llllllldllllllllll..Illllllllllllllllr IIIII INVENTOR Frank H. Swam ATTORNEY Jan. 7, 1969 F. H. sWAlM TIME DELAY MECHANISM Sheet 2 of 2 Filed Oct. 22, 1965 ATTORNEY United States Patent O 4 Claims ABSTRACT F THE DISCLOSURE In an elongate aerial vehicle, an arming device, which is responsive to the rotation yof a shaft extending therefrom and is positioned entirely within the vehicle. A turbine is rigidly atiixed to the shaft for rotation therewith and is air driven via scoop means extending into the slipstream of the vehicle at the rear thereof, an inlet channel for directing the air forward into the vehicle and through the turbine, and an outlet channel for exiting the air at the rear of the vehicle. The inlet channel is slideably mounted, being restrained by an arming wire in a first position to lock the turbine prior to flight but released in Hight to slide to its second position thereby freeing the turbine for rotation.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to a time delay arming mechanism for a fuze and more particularly to a time delay arming mechanism utilizing the air stream surrounding a missile as it is dropped through the air for performing the arming function. The normally employed arming devices for fuzes are located in the center or rear portion of the bomb in such a manner that rotation of a shaft is derived from the air stream vanes or propellers which extend from the tail portion of the bomb or missile. Vanes or propellers disposed externally from the bomb are subject to damage in shipping and handling. Particularly, the propeller or vane may be bent or otherwise deformed from its original shape. Similarly the shaft which connects the fuze mechanism to the vane or propeller is of necessity long and also subject to bending and deformation during shipping and handling.

In the instant invention the need for an external vane on the tail portion of the missile and the long shaft connecting the fuze mechanism to the vane for propeller is eliminated. In the instant invention a turbine blade is provided which is connected directly to a short shaft on a time delay arming device. The turbine and the shaft are located within a cylindrical housing disposed coaxially within the missile. The housing extends from the shaft to the tail portion of the missile and means are provided to introduce slipstream air to the turbine blades for rotating the turbine and arming the fuze of the missile. Duct means are provided for exhausting the air from the turbine.

It is an object of this invention to provide an airoperated turbine located within the body of a missile for arming of the missile.

It is another object of this invention to provide a turbine located withn a lmissile for providing a time delay arming of the missile.

It is still another object of this invention to provide a turbine connected to a shaft of a time delay arming means in a missile and to provide means for rotating said turbine from the slipstream at the rear portion of the missile during flight.

It is yet another object of this invention to provide an air-operated arming means for arming a missile during flight.

It is a still further object of this invention to divert air from the slipstream of a missile during flight through the blades of a turbine for arming the missile during flight.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 of the drawings illustrates the turbine blade and air scoop assembly on the tail portion of a missile;

FIG. 2 illustrates in cross-section the turbine and scoop assembly in the locked position;

FIG. 3 of the drawings illustrates the air scoop and turbine assembly of the delay arming device of the instant invention in the unlocked or operative position;

FIG. 4 of the drawings illustrates a cross-section of the support of the inner tube or duct of the air scoop assembly of the instant invention;

FIG. 5 of the drawings illustrates a cross-section of a thickened portion of the scoop assembly mounted within the outer duct; and

FIG. 6 of the drawings illustrates a rear View of the scoop assembly.

Referring now to FIG. l of the drawings, an aerial device such as a bomb or missile 11 is shown having a fuze 13 with a rotatable shaft 15 projecting therefrom and a fan or turbine blade 17 is mounted on shaft 15 and rotatable therewith. A pair of

scoops

19 and 21 are shown leading into a -central air duct 23. The central air duct 23 is supported coaxially within tubing 25 by spacer assembly 27.

Referring now to FIGS. 2-6 of the drawings, in which the invention is illustrated in greater detail, FIG. 2 in particular shows the scoop assembly in a closed or inoperative position and FIG. 3 shows the scoop assembly in an operative position. An arming wire 29 keeps the device in the inoperative position until the bomb or missile is released from the aircraft carrying the missile. The air turbine 17 is xedly connected to rotatable shaft 15 of fuze 13 by means of a set screw 31 or other suitable fastening means. The air turbine is hollow and has alternate blades and perforations disposed along the circumference near the open end thereof. The blades are disposed in radial alignment. Holes 18 are provided in the turbine to allow air to pass through when the scoop assembly is in the locked position. The center duct 23 is hollow and is closed with plate 33 at one. end thereof. The duct is provided with radially aligned perforations or holes 35 disposed about the circumference near plate 33 at one end of duct 23. The duct is held centrally in place by spacer assembly 27 which may comprise a collar member 37 and spacer bars 39. A lug or key 41 may be provided on one of the spacers 39 which acts to prevent the blades of air turbine 17 from rotating when the scoop assembly is in the locked position.

Scoops

19 and 21 are brought together in a thickened end portion 22 which may be fastened to or integral with inner duct or tubing 23. Thickened end portion 22 is provided with keys 24 which engage slots 26 of outer tube 25. This key and slot arrangement prevents rotation of tube 23 and limits the travel thereof when arming wire 29 is released.

FIG. 4. of the drawings illustrates the coaxial relationship of

tubes

23 and 25 and the spacer arrangement. Spacer assembly 27 is shown having a collar 37 and three spacers 39. The blades of turbine 17 are shown projecting beyond collar 37.

FIG. 5 illustrates a sectional view through the thickened portion 22 of the scoop assembly in which keys 24 engage slots 26 of the outer duct or tubing 25.

FIG. 6 illustrates an end view of the scoop assembly in which

scoops

19 and 21 are shown in relation to the outer duct or tubing 25. Air spaces 55 and 57 are formed between the scoop assembly and outer tubing 25. These air spaces provide for exhausting the air from the turbine. An arming wire 29 is shown projecting through duct 25 and through the scoop assembly. Spacers 39 are shown within tubing 25.

In operation, when arming wire 29 is released and the bomb or missile is dropped, the air pressure of

scoops

19 and 21 will force the duct 23 to move backward to the position as shown in FIG. 3 of the drawings. At this position key 41 will be pulled away from the rotor blades of the turbine 17 and the turbine will be free to rotate. The openings 35 at the end of the duct 23 are now in :radial alignment with the turbine blades. As the missile travels through the air, the forward velocity will cause the air to enter the

scoops

19 and 21 as shown by the arrows and be forced in through duct 23 in a reverse direction to .the iiight of the missile. The air Iwill then be forced out of holes 35 substantially radially and will impinge upon the blades of the air turbine 17 causing the air turbine to rotate, thus causing shaft of the fuze 13 to rotate and arm the fuze after a desired period of time. The air upon passing through the blades of turbine 17 will then again reverse and will travel through an annular chamber formed by the space between the inside of tube 25 and the outside of duct 23. The air will then be discharged through the tail end of the missile through ai-r spaces 55 and 57 shown in FIG. 6. This air flow will continue as long as the missile is in flight and the turbine will rotate. The fuze 13 used in this system may be any fuze which requires a rotational energy input into a shaft for operating a mechanical time delay or other type of mechanism whereby the fuze may be armed after a time or number of revolutions of shaft 15.

Obviously many modifications and variations are possible in the light of the above teachings. It is therefore to be understood, that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. In an elongate aerial vehicle having an arming device, responsive to the rotation of a shaft extending therefrom, wherein said arming device is disposed entirely within the interior of said vehicle, the improvement for controlling the rotation of said shaft comprising,

a turbine iixedly secured to said shaft for rotation therewith; and

means for directing air from the slipstream of said vehicle at the rear portion thereof into the rear of said vehicle, forward into the interior of said vehicle, through said turbine, backward to the rear of said vehicle, and out of said vehicle at the rear portion thereof, whereby said turbine may be air driven so as to rotate said shaft and thereby actuate said arming device,

said air directing means comprising,

a cylindrical outer :tube coaxially aligned with said vehicle,

the forward end of said outer tube extending into the interior of said vehicle, abutting said arming device so as to form a cylindrical cavity within said vehicle, and thereby surrounding said turbine within said cavity, and

the rearward end of said `outer tube extending to the rear of said vehicle and engaging the housing of said vehicle at the rear portion thereof so as to provide an outlet port through which there is open fluid communication between said outer tube cavity and the environment surrounding said vehicle; and

a cylindrical inner tube coaxially aligned with said vehicle and positioned within said outer tube and said outlet port so as to form an outlet passage between the inner surface of said outer tube and the outer surface of said inner tube and so as to form an inlet passage within said inner tube,

the forward end of said inner tube extending into the interior of said cavity and Iterminating adjacent said turbine,

the rearward end of said inner tube extending to the rear of said vehicle so as to form an inlet port, and said inner tube being slidably mounted to the outer tube at the rear thereof in such a manner as to be restrained from rotational movement with respect to said outer tube but free for longitudinal movement with respect to said outer tube from a first forward position to a second rearward position in response to a predetermined vehicle velocity, and means on said inner tube to lock said turbine when said inner tube is in its first position and to release said turbine 'when said inner tube is in its second position, thereby providing a safety locking of said turbine to positively prevent arming of said vehicle prior to attaining a predetermined flight velocity.

2. The apparatus of claim 1 wherein the turbine is hollow and provides a plurality of circumferentially spaced openings axially spaced from the blades of said turbine; the forward end of said inner tube being closed but said inner tube providing a plurality of circumferentially spaced apertures adjacent said closed forward end; said inner tube and said turbine being so positioned with respect to each other that said closed forward end of said inner tube extends within said hollow turbine so that said turbine openings are aligned with said inner tube apertures when said inner tube is in its first position and said turbine blades are aligned with said inner tube aperatures when said inner tube is in its second position.

3. The apparatus of claim 2 further comprising an arming wire connected to the inner tube and the vehicle housing for restraining said inner tube in its first position until said vehicle attains said predetermined ght velocity.

4. The apparatus of claim 1 wherein said inner tube is additionally supported by a spacer assembly fixedly secured to the outer tube, said spacer assembly slidably containing said inner tube near the forward end thereof.

References Cited UNITED STATES PATENTS 1297,273 3/1919 Straub et al 102-81 2,680,407 6/ 1954 Clark l02-8l.2 X 2,766,964 10/1956 Almquist et al. 102-812 X 2,985,105 5/1961 Rabinow et al. 102-81.2 X 3,066,605 12/1962 Jones 102-81 X 3,093,076 6/1963 Blomgren 102-81.2 X

SAMUEL FEINBERG, Primary Examiner.

GERALD H. GLANZMAN, Assistant Examiner.