The Ensign-bickford Company

Dyno Nobel Inc.

Ensign-bickford Industries, Inc.

Ernest L Gladden

Gary R Thureson

Ronald M Dufrane

Frank J Lucca

Eric R Davis

Alvaro Zappalorti

Daniel P Sutula, Jr

Robert G Pallanck

Richard William Spraggs

Nickolay Iliych Rabotinsky

Uriy Gennadievitch Pechenev

Igor Vasilievitch Nikitin

Irina Genadievna Beljankina

Vladimir Vasilievitch Furne

Thomas C Tseka

Daniel A Toro

Thomas F Lilley, Jr

Craig F Adams

Steven L Renfro

J Donaldson Thomas

Joseph W Twarog, Jr

Brian R Sobczak

Thomas A Nadeau

Raymond T Overstrom

James Bayliss

Steven R Pellon

Jeffrey H Burton

Sanford B Tavelli

A signal transmission tube may be made by disposing a reactive polymeric material within a confinement tube and leaving a portion of the tube interior unoccupied. The tube may be formed by disposing a layer of paint comprising the reactive polymeric material on the interior surface of the confinement tube, extruding the confinement tube over an elongate rod that comprises the reactive polymeric material. The rod preferably has a high surface area configuration, e.g., the rod may comprise a longitudinal bore therethrough or may be star-shaped, cross-shaped, etc. Alternatively, the signal transmission tube may be made from the reactive polymeric material. Optionally, a sheath may be extruded over the tubular reactive polymeric material. In various embodiments, the confinement tube or sheath may be configured to be fractured or substantially consumed by the reaction of the reactive polymeric material. Optionally, the reactive polymeric material may comprise a glycidyl azide polymer.

Tubular signal transmission device and method of manufacture

A detonator () has a constant-diameter shell () which has a significantly higher shell length-to-diameter (outside diameter) ratio than prior art detonators. The shell () is configured to hold an explosive output charge () which is cylindrical in configuration and has a charge L:D ratio which is greater than that of prior art constant diameter detonators. As a result, a significant portion of the output signal of the detonator is directed laterally and it is feasible to transfer signals to a plurality of receptor lines disposed along that portion of the length of the detonator which is co-extensive with the length of the explosive output charge (). A connector block () is configured to hold at least one array of receptor lines in side-by-side arrangement along the side of the detonator (), and transversely to the longitudinal axis of the detonator ().

Non-electric detonator

A signal transmission fuse is made of a tube ( ) which encases a support tape ( ) having a reactive coating ( &prime;) which is adhered to one side of the tape by a binder. A method of making the signal transmission fuse includes depositing on the support tape ( ) a reactive paint ( ) including a binder, which paint dries to form a reactive coating ( &prime;). The coated support tape ( &prime;) is then folded, i.e., formed into a channel configuration, to provide an inner concave side of the tape on which the reactive coating ( &prime;) has been disposed. The coated support tape is then enclosed, e.g., within an extruded plastic tube ( ). One side of the support tape may be made of a first material ( ) to which the reactive coating adheres, and a second side may be made of a second material ( ) which bonds or adheres to the inner surface ( ) of the plastic tube ( ) enclosing the coated support tape ( &prime;). The binder causes even high loadings of the reactive coating ( &prime;) to adhere to the coated support tape ( &prime;) to prevent reactive material migration. The support tape also shields the reactive material from the hot, freshly extruded surrounding plastic tube ( ) during manufacture.

Method of making a signal transmission fuse

A signal transmission fuse is made of a tube (,) which encases a support tape (,) having a reactive coating (,&prime;) which is adhered to one side of the tape by a binder. A method of making the signal transmission fuse includes depositing on the support tape (,) a reactive paint (,) including a binder, which paint dries to form a reactive coating (,&prime;). The coated support tape (,&prime;) is then folded, i.e., formed into a channel configuration, to provide an inner concave side of the tape on which the reactive coating (,&prime;) has been disposed. The coated support tape is then enclosed, e.g., within an extruded plastic tube (,). One side of the support tape may be made of a first material (,) to which the reactive coating adheres, and a second side may be made of a second material (,) which bonds or adheres to the inner surface (,) of the plastic tube (,) enclosing the coated support tape (,&prime;). The binder causes even high loadings of the reactive coating (,&prime;) to adhere to the coated support tape (,&prime;) to prevent reactive material migration. The support tape also shields the reactive material from the hot, freshly extruded surrounding plastic tube (,) during manufacture.

Signal transmission fuse

An initiation signal transmission line tube (10a, 10b, 10', etc.), which is effective to transmit an initiation signal therethrough, contains one or more rupture lines (20a, 20b and 20c, etc.) in the tube wall. Rupture lines (20a, 20b and 20c, etc.), which may be weld seams or grooves or both, are ruptured by the initiation signal passing therethrough. The spent tube carcass is split or fragmented and therefore less troublesome as litter on a work site than an intact shock tube carcass. If the tube is extruded, a rupture line may be formed by contacting the parison (118) from which the tube is made with scoring means, e.g., a pin or blade (124a, 124b). Optionally, the scoring means may be moved radially during the extrusion process, to form serpentine, e.g., helical, rupture lines. Preferably, the rupture lines intersect periodically and, upon firing, the tube is fragmented into shards. Alternatively, the tube (50d) may be extruded in segments (62) that adhere to each other at interfaces (64) which provide rupture lines for the tube. Optionally, some segments (62) may be formed from different extrudate materials than others.

Fissile shock tube and method of making the same

A detonator (10) is equipped with an input lead (29) having multiple signal transmission lines (30, 31) which provide redundant initiation signals to the target charge (14) of a detonator (10, 10') thereby increasing the reliability of initiation. The multiple signal transmission lines (30, 31) may be made of shock tube and can be part of a long or short input lead (29, 129) and may be initiated by any suitable means, for example by being disposed in signal transmission relation to a detonating cord (60, 62) to improve the reliability with which a signal is transferred from the detonating cord (60, 62) to the detonator (10, 10').

Detonators having multiple-line input leads

A method and apparatus for transferring non-electric blasting initiation signals from detonating cord signal donor lines to signal transmission tube acceptor lines involves disposing the acceptor line in enhanced signal transfer configuration with the donor line. The acceptor line (30) may constitute the input lead (29a) of a detonator (10a). Enhanced signal transfer configuration between the input lead (29a) and the detonating cord (60) can be established by disposing input line (30) in at least partial wrap-around contact with the detonating cord (60) or in multiple abutting contact with the detonating cord (60). Enhanced signal transfer configuration can also be achieved for a detonator having at least two input lines in abutting contact with the detonating cord. A slider (44) is designed to extend contact between a detonator input lead and a detonating cord. The slider (44) provides a detonator retainer (48) for holding a detonator (10a) and a base fixture (74') that includes a pass-through aperture (58a) for a detonating cord (62). Input lead-retaining means (52) on the base fixture (74') disposes the input lead (29a) in position for enhanced signal transfer configuration with a detonating cord that may extend through the pass-through aperture (58a).

Method and apparatus for transfer of initiation signals

A connector device (10, 214) for transferring a nonelectric blast initiation signal from a donor line (26, 224) to an acceptor line, e.g., an input stub (24, 217) has donor line retaining means (20a, 20b, 229) for disposing a donor line (26, 224) in signal transfer relation to the input stub (24, 217). An anvil member (27, 130, 226) is provided to support input stub (24, 217) at the point where it is in signal transfer relation with the donor line (26), preferably in conforming contact with the donor line (26). In a particular embodiment, the connector device has a body portion (10a) on which is retained a detonator cap (22). Cap (22) detonates upon receipt of a detonation signal from an input stub (24), optionally after a delay period if delay elements are incorporated into the cap 22. The connector device (10) has retainer spring clips (20a, 20b) for retaining the donor line (26) in signal transfer relation to the input stub (24). An output line retaining member (16) holds the output line (28) in signal transfer relation to the detonator cap (22).

Connector for blast initiation system

An isolation member (34) for use in a non-electric detonator cap (10) has an interior passageway (40) extending therethrough and defining a positioning region (44) and a discharge port (56). Positioning region (44) provides a series of interior shoulders (46), (48) and an entry shoulder (52) respectively sized to receive and seat therein signal transmission lines of different outside diameters, thereby longitudinally orienting and spacing the signal-emitting end (30a) from the receptor charge (14). The isolation member (34) is preferably made of a semi-conductive material to bleed off to the shell (12) any static electricity charges transmitted through the signal transmission line (shock tube 30) so as to prevent static discharge initiation of the receptor charge (14).

Universal isolation member and non-electric detonator cap including the

A signal transmission fuse (10, 20) such as shock tube has an outside diameter (OD) not greater than about 2.380 mm (0.0937 inch), for example, a tube outside diameter (OD) of from about 0.397 to 2.380 mm (about 0.0156 to 0.0937 inch), and the ratio of the inside diameter (ID) of the tube to the radial thickness of the tube wall (T) is from about 0.18 to 2.5. The inside diameter (ID) of the tube may be from about 0.198 to 1.321 mm (about 0.0078 to 0.0520 inch). The powder surface density of the reactive material contained within the bore (16, 30) of the fuse (10, 20) may, but need not, be significantly less than that which the prior art considers to be a minimum acceptable powder surface density. Other things, such as the cost of the material used being equal, signal transmission fuse (10, 20) of the present invention is lower in cost than conventional standard sized fuse because of its reduced diameter, and yet has good stiffness and tensile strength so as to enable it to be successfully deployed and used in the same manner as standard size signal transmission fuse.

An improved detonator includes a housing having an open end and an opposite, closed end and defining an axially-extending channel of the housing. A cushion element containing at least one aperture is disposed within the channel and is provided with a resilient, pliable and shock absorbent surface for contacting and retaining explosive material at the closed end of the detonator housing. The cushion element has a signal communicating membrane covering its at least one aperture for passage therethrough of an initiating signal to the explosive material. A method for assembling the detonator includes inserting explosive material into the axially extending channel of the detonator housing, inserting a cushion element having a signal communicating membrane into the channel, and pressing the cushion element towards the closed end of the housing for compacting the explosive material between the cushion element and the closed end of the housing.

Cushion element for detonators and the like; apparatus and method of

An isolation member (34) for use in a non-electric detonator cap (10) is of substantially cylindrical shape and has an interior passageway (40) extending therethrough and defining a positioning region (44) and a discharge port (56). Positioning region (44) is dimensioned and configured to snugly receive and seat therein a signal transmission line (30) and to orient the signal-emitting end (30a) thereof to aim along the longitudinal axis of cap (10) through a diaphragm (42) at the target provided by receptor charge (14). The isolation member is positioned between, and spaces the signal-emitting end (30a) of the signal transmission line (30) from, the receptor charge (14) contained in the detonator cap. The isolation member comprises grooves (58, 58a, 58b) to provide an alternate flow path through which a signal emitted by the discharge end (30a) of a signal transmission line (30) can reach the receptor charge (14) should the signal fail to burst the diaphragm (42 ). The isolation member is preferably made of a semi-conductive material to bleed off to the shell (12) any static electricity charges transmitted through the signal transmission line (shock tube 30) so as to prevent static discharge initiation of the charge.

Alternate signal path isolation member and non-electric detonator cap

A signal transmission tube assembly includes a signal transmission tube, such as a coil of shock tube on a spool, having opposite terminal ends and containing a reactive material. The open terminal ends of the shock tube provide the sole exits for the signal generated therein and the sole entry points for contaminants. Sealing means seal both terminal ends of the signal transmission tube against escape from the assembly of the signal engendered by initiated reaction of the reactive material, and protects the interior of the signal transmission tube from contamination. The sealing means may be a releasable sealing means which can be actuated to release the transmission tube from it, thereby facilitating re-use of the sealing means. Further, the sealing means may comprise a surge chamber to relieve pressure engendered by reaction of the reactive material and thereby militate against rupture of the signal transmission tube and consequent release from the assembly of a signal. A signal-rupturable diaphragm may be interposed between the signal transmission tube and the surge chamber.

Shock tube assembly

A delay train ignition buffer (45) is positioned between a transmission tube (11) and a delay train (25) in a detonator housing (15) or a signal transmission tube housing. The buffer controls the rate at which the transmission tube temperature/pressure pulse is applied to the delay train pyrotechnic surface, attenuating the effects of the pulse with a resulting improvement in delay timing precision. The buffer also attenuates the effects of sudden depressurization within the detonator resulting from the rupture of the transmission tube or ejection of the tube from the housing, thereby preventing separation of the reacting pyrotechnic which could otherwise cause the reaction to cease at the point of separation, thus causing failure of the delay train to continue combustion of the pyrotechnic through its length.

Delay train ignition buffer

Blasting signal transmission tube comprising a length of elongated flexible hollow tube and a self-oxidizing combustible substance disposed within the tube for transmitting a blasting signal along the interior of the tube length, the hollow tube having a varying interior axial cross-sectional area at longitudinally spaced intervals along the tube length for reducing and controlling the velocity of the blasting signal. Also, a process for producing signal transmission tube comprising forming a length of elongated flexible hollow tube of predetermined interior cross section area; depositing a self-oxidizing combustible substance within the tube for transmitting a blasting signal along the interior of the tube length without destroying the tube; and introducing a plurality of discrete restrictions reducing the predetermined hollow tube interior cross-sectional area at longitudinally spaced intervals along the tube length for reducing and controlling the velocity of the blasting signal.

Growing community of inventors

Granby, CT, United States of America

Ernest L Gladden