US 3078799 A
Description (OCR text may contain errors)
Feb. 26, 1963 l. KABIK 3,078,799
DELAY SYSTEM Filed sept. 29. 1960 lll/111111111 INV EN T IIIlIllllllll-L lRvlNs K K l ATTYS.
Unite rates 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 an improvement in fuses and more particularly to an improvement in the method of holding and igniting a time delay fuse train.
Heretofore it has been common practice in a vented fuse to provide an initiator plug on one end of the fuse, a time delay fuse column on the other with a chamber in between having vent holes for allowing the gases to escape. This construction did not always achieve the desired result for the following reasons:
(l) Part of the hot gases utilized in the fuse initiator to ignite the fuse train escaped directly out of the vent holes on ignition without coming into contact with or igniting the delay fuse train; and
(2) Possible separation in the delay fuse column due to a decrease in density exhibited by the products of combustion of the gasless delay composition, the separation resulting primarily due to the evolved gases acting against the unsupported column.
Any separation in the fuse delay column may result in extinction of the burning of the column, resulting in a dud unit.
The general purpose of this invention is to provide a time delay fuse which embraces all the advantages of similar prior art devices but possessing none of the aforedescribed disadvantages. To attain this, the present invention contemplates a unique single continuous column thereby avoiding any separation of the delay fuse column, a labyrinth path for the initiating hot gases, combined in such a manner so as to assure ignition of the delay column before venting. The porous disk also allows an escape path for any gases given off by the delay powder.
An object of this invention is to provide a fuse with a new and improved delay fuse column having a uniform density.
Another object is to provide a new and improved fuse having all parts in continuous Contact during ignition and burning.
A further object is to provide a new and improved positive method of igniting the delay fuse train prior to venting of the igniting gases.
A stili further object is to provide a unique construction for maintaining the delay powder in a compressed condition while allowing the gases given off by the delay powder a path of escape.
Further obiects and the entire scope of the invention will become further apparent in the following detailed description and in the appended claims. The accompanying drawing displays the general construction and operational principles of an embodiment of the invention. It is to be understood, however, that the drawing is furnished only by way of illustration and not in limitation of the invention and in which the single ligure is a side elevational view of the invention showing the general construction of a preferred embodiment thereof.
Referring now to the drawing, there is illustrated a time delay fuse il. The time delay fuse fil has an initiator assembly l2. which comprises an initiator plug 13. The plug 13 may be made of any insulator material, for example, a phenolic, or Kovar glass, depending upon the atet f y intensa Patented Feb. 26, 1963 "ice design. Plug 13 has a pair of electrical contacts 14 extending therethrough which are connected to a bridge Wire i5. The initiator plug 13 is snugly seated in a charge holder 16. A charge 17 is centrally located in the charge holder 16 and in contact with the bridge Wire 15. The charge holder i6 has a chimney 18 which is designed and seated on the porous disk 23 so as to allow gases to be vented from the delay body within which it will be used. The chimney 18 also directs the hot gases from the blast of the charge li of the initiator assembly l2, past the vent holes 19, in the fuse container 2li, through the porous disk 23 to the next succeeding explosive increment. The charge 17 in the charge holder 16 may contain various mixtures 2l, for example, lead styphnate surrounding the bridge wire followed by an ignitor mixture Z2. The initiator assembly l2 is placed upon the porous disk 23 in the uper end of fuse container 2i). The fuse container it may be either crimped or soldered onto the initiator plug 13 substantially as shown. The delay powder 24 is the so-called gasless powder and may be loaded from the other end of the fuse container. A gasless powder for example, is composed of a barium chromate, lead chromate and a manganese mixture. A heat sensitive powder .25 which is well known to those skilled in the art is located adjacent to or may be pressed into the pores of the porous disk 23 followed by the delay powder 24 having a time delay characteristic which is pressed into the column until a predetermined height is achieved dependent upon the desired delay time. This is followed in the order named by a similar heat sensitive igniter material 26, a forced litted slotted baille 27, another heat sensitive igniter material 2.3, a base charge 29 and a copper disk 30 which is crimped over the bottom of the container to complete the delay fuse. The delay charge may, for example, be an actuator charge, a propellant charge or a detonator. The upper and lower ends of the container are to be interpreted with reference to the drawing.
When suiiicient electrical energy is passed through the wire bridge l5, the temperature of the wire is raised high enough to initiate the lead styphnate 2l. This in turn initiates the ignito-r mixture 22 causing the hot particles and gases to pass down the chimney 13 into and through -a labyrinth path in the porous disks Z3 thereby initiating the next ignitor increment 25 and then passing out the vent holes i9 in the cylinder. The small amount of gas formed by the delay charge also will pass out of the porous metal disk 23 and through the vent holes 19.
The delay powder 24 is pressed to a uniform density and held in place by the slotted baflle 27. As the delay powder 24 burns it tends to expand having a residue or slag material which is compressed by the porous disk 23 rand slotted baffle 27 into the same volume as the powder originally occupied. The residue products of combustion of the delay powder 24 would in the absence of such confinement be substantially less dense than the delay powder 24 thereby occupying more volume and would tend to separa-te if it was not held in place by the porous disk 23 and slotted baffle 27.
The porous disk 23 thereby provides support for the delay column so that it cannot separate and at the same time allowing any gases resulting from the burning powder to escape. A heat sensitive ignition powder 26 and Z8 is loaded on both sides of the baille 27 to ensure that the fuse will continue to burn through the bathe 27. The base charge 29 may be used to explode a larger device or operate a switch as shown in a copending application Serial Number 62,511, filed October 13, 1960.
The porous disk Z3 is composed of stainless steel sintered material which may be obtained in various porosities. The porosity found most suitable for this application is P.S.S. grade c with a mean pore opening of microns.
Obviously many modifications and variations of the present invention 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 as new and desired to be secured by Letters Patent of the United States is:
l. An electrically detonated time delay fuse for an explo-sive device, said fuse including a container having apertures located therein, an electrical initiator means located in one end of said container for initiating the fuse column when energized, a chimney type charge holder located in said container and partially surrounding said initiator means, a cha-rge located in said charge holder and responsive to said initiator means when energized, a porous disk of substantially the same area as the inside area of said container and in contact with said charge holder, a gasless time delay powder column located in said container adjacent -said porous disk, a slotted balile restraining said gasless delay powder at a uniform density between said porous disk and said slotted barile before initiating the fuse, said vslotted bafe and porous disk maintaining the unburned portion of said gasless delay powder at a uniform density after initiating the fuse, a disk sealing the end of said container and forming a chamber between said slotted battle and said sealing disk, base charge means located in said chamber and ignitible by the burning of said time delay powder, said electrical initiator means igniting said charge means causing the hot gases to ilow down the chimney through a plurality of labyrinth paths in the porous material thereby igniting the delay powder before being vented out the apertures in said container.
2. A time delay fuse for an explosive device comprising a container member for holding the component parts of the fuse in continuous contact with each other and having venting apertures therein, an initiator means located at one end of said container member for initially igniting said fuse, a chimney-type charge holder located in said container and in contact with said initiator means, a charge located in said charge holder in contact with and responsive to said initiating means for creating a large quantity of hot gases when ignited, a porous disk press tted in said container and in contact with and closing the exposed portion Iof said chimney-type charge holder in such a manner that the hot gases flow through the porous disk to reach the venting apertures 0f said container, a slotted baille, a time delay charge of a predetermined length held at a uniform density by said slotted baille at `one end and said porous disk at the other end of said delay charge before ignition of said fuse, said slotted bathe and porous disk maintaining the unburned portion of said delay charge at a uniform density after ignition of said fuse, a metallic disk closing the other end of said container and forming another chamber at said other end thereof, a base charge located in said chamber and ignitible by said delay charge for actuating the explosive device.
3. A time delay fuse for actuating an explosive device comprising a container having a plurality of apertures tainer, a time delay charge located in said container and held compressed at a uniform density before ignition against said porous disk and being ignited by said hot gases passing through said porous disk, a slotted baffle for maintaining the unburned portion oi said delay charge at a uniform density after ignition, said slotted bale forming -achamber with a metallic disk at the other end of said container, and a base charge completely filling said chamber.
4. A time delay fuse for an explosive device comprising a container having apertures therein, a base charge in said container, a time delay column adapted to ignite said base charge, a porous disk means for holding the time delay column at a uniform density before ignition and maintaining the unburned portion of said delay column at a uniform density after ignition, said porous disk providing an igniting path to said delay column, an initiating means for providing a quantity of hot gases which are forced through said porous disk prior to being vented through the apertures in said container' thereby igniting said time delay column.
5. A time delay fuze according to claim 4 in which the initiating means includes an electrical initiator plug, a chimney-type charge holder having one end thereof mounted on said porous disk means, a charge located in said holder for giving oit hot gases when ignited, said electrical initiator being mounted on theother end of said charge holder and in contact with said charge whereby when said charge is ignited by said electrical initiator the hot gases pass down the chimney-type charge holder through the porous disk to ignite said time delay column.
6. A fuze for an explosive device comprising a container having apertures therein, a base charge located in one end of said container, an actuator train located in close proximity to said base charge and adapted to ignite said base charge, a baiile plate located between said base charge and said actuator train, a disk of sintered material for initially compressing said actuator train to a uniform pressure between said disk and said baffle plate, an electrical initiator plug located in the other end of said fuze, a pair of electrodes extending through said plug into the fuze, an electrical responsive bridge wire connected between said pair of'electrodes, an initiator charge located in close proximity to said bridge wire and responsive thereto for generating a quantity of hot gas when ignited, a chimney type charge holder with one end incasing said charge and one end of said plug and the other end of said charge holder abutting said disk whereby the hot gas of Vthe initiator charge is directed by the charge holder into and through the sintered material to ignite the actuator train.
7. A time delay fuze for an explosive device comprising a cylinder having a bore along the longitudinal axis thereof, said cylinder having a plurality of apertures normal to said bore and connected thereto, a base charge located at one end of the bore, a time delay column adjacent said base charge and adapted to ignite said charge, a sintered disk means for compressing said delay column and providing an igniting path to said delay column, an initiator means located at the other end of the bore for generating a quantity of hot gases, and a chimney-type charge holder with one end incasing one end of said initiator means and the other end abutting said sintered disk means, said charge holder directing all the hot gases into and through a plurality of labryinth paths in said sintered disk to ignite said delay column.
8. A fuze ior an explosive device comprising a cylinder having a bore along the longitudinal axis thereof, an initiator means located in one end of the bore for initiating the fuze when energized, a chimney-type charge holder Vlocated in the bore with one end partially surrounding Vsaid initiator means, a charge means located in said charge holder responsive to said initiator means for generating a quantity of hot gas, a porous disk of sintered material of substantially the same area as the inside area Vof the bore and abutting the other end of said charge holder, a slotted baiiie located near the other end of said bore, a time delay column compressed to a uniform density between said porous disk and said slotted bale, a disk sealing said other end of the bore and forming a chamber between said slotted baille and said scaling disk, and a base charge located in said chamber and ignitable References Cited in the le of this patent UNITED STATES PATENTS Bacon June 17, 19,30 McKnight Jan. 20, 1959