GB2577798A

GB2577798A - A primer holder device

Info

Publication number: GB2577798A
Application number: GB1911890.0A
Authority: GB
Inventors: Mckernan Michael
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-08-18
Filing date: 2019-08-19
Publication date: 2020-04-08
Anticipated expiration: 2039-08-19
Also published as: WO2020039332A1; GB201813483D0; IE87238B1; GB201911890D0; GB2577798B; IE20190141A1; EP3837489A1

Abstract

A holder device for housing a primer or booster device comprises an elongate body comprising a cavity for housing at least one primer or booster device. The elongate body has a circular cross-section and is cylindrical in shape comprising a rounded distal end and an open proximal end and at least two protruding side flaps or wings 7. The elongate body comprises two longitudinal sidewalls 5 hingedly attached along one longitudinal side and openable along the other longitudinal side.

Description

"A Primer Holder Device"

Introduction

The invention relates to a holder device for holding a primer or booster device used in blasting in mines.

Blasting is a common technique in mining for fracturing a substrate, such as rock, to facilitate excavation and removal. Blasting involves controlled explosions, typically using shells that contain an explosive charge that is initiated by a primer or booster. A primer or booster is a device for initiating an explosive and may be in the form of an explosive device that has transmission wires/ activation leads attached to initiate the explosive from a remote position. The explosive charge is primed with the primer or booster sitting in the explosive or explosive cavity region, with the transmission wires/activation leads extending up to the surface of the blast hole. The primer or booster is then fired triggering detonation of the explosive charge of the primer or booster which in turn detonates the bulk explosive.

Inserting the primer or booster and positioning it in its optimum position for a successful blast can be very problematic with non-detonation or misfiring occurring sometimes.

There is a need for an improved device to ensure that a primer or booster device are always placed securely and correctly in their optimum position.

Statements of Invention

According to the invention there is provided a holder device for housing a primer or booster device comprising an elongate body comprising a cavity for housing at least one primer or booster device, the elongate body comprising two sidewalls hingedly attached along one longitudinal side and openable along the other longitudinal side, having a circular cross-section and cylindrical in shape comprising a distal end and an open proximal end, wherein each sidewall comprises an elongate opening or slot with at least one protruding flap or wing extending from the distal end of the elongate opening or slot.

In one embodiment of the invention the elongate body comprises a snap-fit closure means along the openable longitudinal side.

In one embodiment of the invention the protruding flap is rectangular in shape.

Preferably the protruding flap comprises angled barbs on its outer face. Most preferably the protruding flap comprises a ridged surface on its inner face.

In one embodiment of the invention the inner walls of the open proximal end comprise a number of protruding ribs.

In one embodiment of the invention the base section of the open proximal end comprises a central opening.

In another embodiment of the invention the distal end of the device is rounded in shape.

Alternatively the distal end may comprise a tapered or pointed shape.

In one embodiment of the invention the distal end comprises indents.

In another embodiment of the invention the holder device comprises a number of openings in the sidewalls.

In one embodiment of the invention the holder device is capable of accommodating a primer or booster device ranging in size from approximately 36mm to 240mm.

In another embodiment of the invention the sidewalls are approximately 3 mm to 5 mm thick. Preferably the device is manufactured from a plastics material.

Brief Description of the Invention

The invention will be more clearly understood from the following description thereof with reference to the accompanying drawings in which: -Fig. 1 is a perspective view from the front of the holder device of the invention; Fig. 2 is a further perspective view from the rear of the holder device of the invention; Fig. 3 is an end view of the distal end of the holder device of Fig. 1; Fig. 4 is an end view of the proximal end of the holder device of Fig. 1; Fig. 5 is a perspective view of the outside of the holder device of Fig. 1 in its open position; Fig. 6 is a perspective view of the inside side of the holder device of Fig. 1 in its open position; Fig. 7 is a perspective view towards the proximal end of the device of Fig. 5 in its opened position; Fig. 8 is a further perspective view from the proximal end of the device of Fig. 5 in its opened position; Fig. 9 is a perspective view of the inside of the holder device of the invention with a primer or booster in position; and Fig. 10 is a further perspective view of the inside of the holder device of the invention with a larger sized primer or booster in position.

Detailed description

The present invention provides a holder device to contain a primer or booster device and ensure that it is safely and accurately delivered into the correct position within a blast hole resulting in a successful explosion.

Inserting a primer or booster device into a bore hole can be problematic. Correct positioning of the primer or booster device is essential in creating the intended blast direction/splay. It can be difficult to get them safely down a bore shaft and into the correct position without any damage to the primer or booster device as it is being inserted into a blast hole.

Bore holes may be drilled in various directions for example upwards, downwards or sidewards and inserting the primer or booster device into such orientated holes can be problematic. Another commonly encountered problem is that the primer or booster device gets snagged along the way as it is inserted into the drill or bore hole.

The holder device of the present invention overcomes the problems encountered with known devices in the mining industry comprising an explosive charge /detonator/ primer or booster.

The holder device 1 of the present invention comprises an elongated body having a distal end 2 and an open proximal end 3. The distal end 2 is preferably rounded but may alternatively be tapered or pointed to facilitate insertion into a blast hole. The elongated body is essentially circular in cross-section and is essentially cylindrical in shape to facilitate insertion and explosion in a blast hole.

The elongated body comprises two longitudinal sidewalls 4, 5 which are essentially identical. The sidewalls 4, 5 are permanently hingedly attached along one longitudinal side with an openable closing along the other longitudinal side. The openable closing comprises a snap-fit closure means 21 or any other suitable closure means.

The holder device 1 is opened to insert a primer or booster device 20 and then securely snapped closed.

The holder device comprises a cavity arranged to snugly contain at least one a primer or booster device 20 securely in position within the cavity. The elongated body comprises an essentially smooth outer wall to facilitate insertion into a blast hole.

Each sidewall 4, 5 of the elongated body comprises an elongated opening or slot 6. The distal end of the slot 6 comprises a protruding flap or wing 7. The protruding flap or wing 7 is flexible and essentially spring loaded. When in an enclosed space the flap 7 lies flush against the sidewall 4, 5, however when in a wider space the flaps 7 extend outwardly from the sidewalls 4. 5. The protruding flap or wing 7 comprises angled barbs 8 on its outer face. The inner face of the protruding flap or wing 7 comprises a ridged surface for increased stability. Preferably the flap comprises longitundinal ridges 9. The angled barbs 8 provide extra grip and ensure that the holder device 1 cannot be pulled back of the blast hole once the holder device 1 is inserted into a blast hole and the flaps 7 have extended outwardly from the sidewalls 4, 5. The protruding flaps or wings 7 ensure that the holder device 1 is held securely in position once inserted into a blast hole no matter what the orientation of the blast hole ie. upwards, downwards or sidewards.

The cavity of the holder device 1 may be adapted and sized to accommodate any length or size of primer or booster device. For example the cavity may be sized to accommodate conventional primer or booster devices which range in length from 20 approximately 36 mm to 240 mm.

The rounded distal end 2 of the primer holder 1 comprises indents 14 to strengthen the outer wall of the holder device 1. The rounded distal end 2 also comprises openings 15. The holder device has more openings 15 along the sidewalls 4, 5.

The proximal end 3 of the holder device 1 is open ended and comprises receiving means for receiving a hose pipe. The inner walls of the proximal end 3 comprise a number of protruding ribs 11 to securely engage with a hose pipe delivering liquid explosive to the holder device 1. The protruding ribs 11 may be sized and shaped to accommodate differently sized hose pipes. The base section 12 of the proximal end of the device 1 comprises an opening 13.

In use the holder device t is opened and a primer or booster device 20 inserted into the cavity. The side walls 4, 5 of the holder device 1 are then snapped closed. Activation leads or transmission wires (not shown) embedded within the primer or booster device 20 extend through the opening 13 in the proximal end 3 of the holder device 1. A hose is attached to the proximal end 3 of the holder device 1 and the device 1 with the activation leads and hose extending therefrom is inserted into a blast hole.

Once in position within a blast hole the protruding flaps or wings 7 expand outwards securing the holder device 1 in position within the blast hole. Once securely in position liquid explosive is pumped through the hose filling the cavity of the holder device 1 around the primer or booster device 20 and pouring out through the openings 15 and the elongated slots 6 to surround the holder device 1 within the blast hole with liquid explosive. The hose is then retracted, the activation leads or transmission wires attached to a detonator/activator at a remote distance to the blast hole and the primer or booster device 20 within the holder device 1 is detonated.

The design of the holder device of the present invention significantly reduces the chance of a misfire or the incorrect positioning of a primer or booster device within a bore hole. Misfires are a significant safety and financial risk.

The primer or booster holder device 1 of the present invention is manufactured from a durable material preferably a plastics material. The material is strong enough to safely encase a primer or booster device and withstand insertion into a blast hole. The plastics material is lightweight yet durable.

The sidewalls of the holder device are approximately 3-5mm in thickness. The holder device is designed to withstand pressures greater than 10 MPa and up to approximately 40 MPa.

The invention is not limited to the embodiment hereinbefore described, with reference to the accompanying drawings, which may be varied in construction and detail.

Claims

Claims A holder device for housing a primer or booster device comprising an elongate body comprising a cavity for housing at least one primer or booster device, the elongate body comprising two sidewalls hingedly attached along one longitudinal side and openable along the other longitudinal side, the elongate body having a circular cross-section and cylindrical in shape comprising a distal end and an open proximal end, wherein each sidewall comprises an elongate opening or slot with at least one protruding flap or wing extending from the distal end of the elongate opening or slot.
2. A holder device as claimed in claim I wherein the elongate body comprises a snap-fit closure means along the openable longitudinal side.
A holder device as claimed in any preceding claim wherein the protruding flap is rectangular in shape.
A holder device as claimed in any preceding claim wherein the protruding flap comprises angled barbs on its outer face.
5. A holder device as claimed in any preceding claim wherein the protruding flap comprises a ridged surface on its inner face.
A holder device as claimed in any preceding claim wherein the inner walls of the open proximal end comprise a number of protruding ribs.
7. A holder device as claimed in any preceding claim wherein the base section of the open proximal end comprises a central opening.
A holder device as claimed in any preceding claim wherein the distal end of the device is rounded in shape.
A holder device as claimed in any preceding claim wherein the distal end comprises a tapered or pointed shape.
10. A holder device as claimed in any preceding claim wherein the distal end comprises indents.
1 1. A holder device as claimed in any preceding claim comprising a number of openings in the sidewalls.
12. A holder device as claimed in any preceding claim capable of accommodating a primer or booster device ranging in size from 36mm to 240mm.
13. A holder device as claimed in any preceding claim wherein the sidewalls are approximately 3 mm to 5 mm thick.
14. A holder device as claimed in any preceding claim manufactured from a plastics material