Connector block for shock tubes and method of securing a detonator therein

Abstract

A method of producing an assembly of a connector block ( 1, 21, 40 ) and a detonator ( 5, 25,41 ) suitable for retaining at least one shock tube ( 4, 24 ) adjacent to a percussion-actuation end ( 15, 26 ) of the detonator, and to an assembly thus produced and a connector block therefor. The method comprising inserting a detonator into a connector block having a housing ( 2, 22, 40 ) provided with a bore ( 13, 31, 44 ), positioning the detonator in the bore of the housing so that the percussion-actuation end of the detonator is positioned adjacent to a slot ( 14, 35 ) for receiving the shock tubes; and fixing the detonator in the housing. The detonator is fixed in the housing by causing a body of material ( 10 ) to flow plastically into the recess in the detonator and to harden therein to form a locking element fixed to the housing, thereby preventing accidental movement of the detonator within the connector block.

1 . A method of producing an assembly of a connector block and a detonator suitable for retaining at least one shock tube adjacent to a percussion-actuation end of the detonator, the method comprising inserting a detonator into a connector block, said detonator having a percussion-actuation end and an outer wall provided with an inwardly directed recess at a position remote from said percussion-actuation end, and said connector block having a housing provided with a bore for receiving said detonator, as well as a shock tube retention means provided on the housing at an end of the bore adjacent to the percussion-actuation end of the detonator, said shock tube retention means defining with said housing a slot for receiving at least one shock tube and holding said at least one shock tube adjacent to the percussion-actuation end of the detonator; positioning the detonator in the bore of said housing so that the percussion-actuation end is positioned adjacent to said slot; and fixing the detonator in the housing; wherein the detonator is fixed in the housing by causing a body of material to flow plastically into said recess in the detonator and to harden therein to form a locking element fixed to said housing, thereby preventing accidental movement of said detonator within said connector block.  
   
   
       2 . A method according to  claim 1 , wherein the step of causing the body of material to flow plastically into said recess comprises: applying ultrasonic or thermal energy to the region of the housing adjacent to the recess in the detonator, applying inwardly directed pressure to the said region to cause a part of the housing to flow as said body into said recess; and allowing said body of material to harden in said recess.  
   
   
       3 . A method of  claim 2 , wherein the ultrasonic or thermal energy is applied using an ultrasonic or thermal device, said device comprising a probe for applying said ultrasonic or thermal energy to the housing.  
   
   
       4 . The method of  claim 2 , wherein said pressure is applied simultaneously with the ultrasonic or thermal energy.  
   
   
       5 . The method of  claim 2 , wherein said pressure is applied subsequently to the ultrasonic or thermal energy, before the body of material hardens.  
   
   
       6 . A method according to  claim 1 , wherein the step of causing the body of material to flow plastically into said recess comprises injecting the body of material in a fluid state through at least one hole passing through a wall of the housing located adjacent to the recess of the detonator located therein, the body of material being injected into said recess; and hardening the body of material in said recess.  
   
   
       7 . The method of  claim 6 , wherein the body of material is injected through two holes on opposite sides of the housing.  
   
   
       8 . An assembly of a connector block and a detonator suitable for retaining at least one shock tube adjacent to a percussion-actuation end of the detonator, produced by a method according to  claim 1 .  
   
   
       9 . A connector block and detonator assembly for retaining at least one shock tube adjacent to a percussion-actuation end of a detonator, the assembly comprising: a housing having a bore formed therein; an elongated detonator inserted in the bore, the detonator having a percussion-actuation end and an outer wall provided with an inwardly directed recess at a position remote from said percussion-actuation end; and a shock tube retention means provided on the housing at an end of the bore adjacent to the percussion-actuation end of the detonator, said shock tube retention means defining with said housing a slot for receiving at least one shock tube and holding said at least one shock tube adjacent to the percussion-actuation end of the detonator; and a locking element fixed to the housing and extending into said recess for securing the detonator within the connector block in a position for initiation of the shock tubes, wherein said locking element is a hardened body of material caused to flow plastically into and harden within said recess after insertion of said detonator in said bore.  
   
   
       10 . An assembly according to  claim 9 , wherein the housing is made of a material that is mouldable and wherein the body of material is part of the housing.  
   
   
       11 . An assembly according to  claim 10 , wherein the material of the housing is thermoplastic and said body results from heating and moulding part of the material of the housing.  
   
   
       12 . An assembly according to  claim 10 , wherein the material of the housing is mouldable upon exposure to ultrasonic energy, and said body results from exposure of part of said housing to ultrasonic energy followed by deformation of said part to cause said part to flow into said recess.  
   
   
       13 . An assembly according to  claim 9 , wherein said locking element is a product of injection of a settable locking material in a fluid state into said recess through a wall of said housing, followed by setting of said settable locking material.  
   
   
       14 . An assembly according to  claim 13 , wherein the bore is configured to include a recess adjacent to the recess of the detonator, said settable locking material engaging both the recess of the detonator and the recess of the bore, thereby locking said detonator in position upon setting of said settable locking material.  
   
   
       15 . An assembly according to  claim 9 , wherein the assembly further comprises a positioning member located at said end of said bore for accurately positioning the percussion-actuation end of the detonator in signal transfer relationship with said at least one shock tube located in the slot.  
   
   
       16 . An assembly according to  claim 9 , wherein the locking element comprises a deformed portion of the housing adjacent to said recess.  
   
   
       17 . An assembly according to  claim 16 , wherein the thickness of the deformed portion of the housing is less than an average thickness of the housing.  
   
   
       18 . An assembly according to  claim 14 , wherein the settable locking material comprises an epoxy adhesive.  
   
   
       19 . An assembly according to  claim 14 , wherein the settable locking material comprises an anaerobic adhesive material.  
   
   
       20 . An assembly according to  claim 19 , wherein said anaerobic adhesive material is a cyanoacrylate adhesive.  
   
   
       21 . A connector block for retaining at least one shock tube adjacent to a percussion-actuation end of a detonator, the connector block comprising: a housing having a bore formed therein for receiving an elongated detonator having a percussion-actuation end and an outer wall provided with an inwardly directed recess at a position remote from said percussion-actuation end; and a shock tube retention means provided on the housing at an end of the bore adjacent to the percussion-actuation end of the detonator, said shock tube retention means defining with said housing a slot for receiving at least one shock tube and holding said at least one shock tube adjacent to the percussion-actuation end of the detonator; wherein said housing includes means for enabling a body of material to flow plastically into and harden within said bore at a position corresponding to said recess in said detonator when positioned in said bore to form a locking element for securing a detonator within the connector block.  
   
   
       22 . A connector block according to  claim 21 , wherein said means comprises at least one recess in said housing for receiving an ultrasonic or thermal probe.  
   
   
       23 . A connector block according to  claim 22 , wherein two recesses are provided in said housing for receiving an ultrasonic or thermal probe arranged on opposites sides of the housing.  
   
   
       24 . A connector block according to  claim 21 , wherein the means for enabling said body of material to flow plastically and harden within said bore comprises a part of the housing that is made of a material that can be caused to flow plastically.  
   
   
       25 . A connector block according to  claim 21 , wherein said means for enabling said body of material to flow plastically and harden within said bore comprises at least one hole passing through a wall of the housing to allow injection of said body of material.  
   
   
       26 . A connector block according to  claim 25 , wherein said at least one hole comprises two holes arranged on opposite sides of the housing.  
   
   
       27 . A method for securing a detonator within a connector block as defined in  claim 21 , wherein the method comprises the steps of: inserting a detonator into the bore of the housing; positioning the percussion-actuation end of the detonator at the signal transmission end of the bore, in a position for energy transmission from the surface of the percussion-actuation end of the detonator to the slot and the shock tubes subsequently retained therein; and molding a body of material around the recess of the detonator, to secure the detonator within the connector block.