GB2467999A

GB2467999A - Explosive charge priming aid and insertion tool

Info

Publication number: GB2467999A
Application number: GB0920278A
Authority: GB
Inventors: Nicholas John Camm; Paul Anthony Atherton
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-09-30
Filing date: 2009-11-19
Publication date: 2010-08-25
Anticipated expiration: 2029-11-19
Also published as: GB2467999A8; GB2467999B; GB0920278D0

Abstract

An explosive charge handling tool (Q) for use with shaped explosives as used in hard rock mining, comprises of two sleeve assemblies (M, N), one fitting inside the other. An outer of the two sleeve assemblies (M) includes the means to hold and grip a primed capped charge (A). An inner of the two sleeve assemblies (N) includes the means to hold a detonator (J) and collar (L) in position. Inserting the inner sleeve assembly (N) into the outer sleeve assembly (M) provides alignment and insertion of the detonator (J) into the charge (A). The inner sleeve assembly (N) also provides rock bore gripping and sealing means comprising of a tapered plug drawn an expanding section around which is fitted a grip ring (D). The further the plug is pulled through the grip ring (D) the further the grip ring (D) expands resulting in a harder grip and a tighter seal in the rock bore.

Description

Page 1

DESCRI PTION

Explosive Charge Priming Aid and Insertion Tool This invention relates to a device for priming a shaped explosive charge then inserting and sealing the primed charge into a prepared bore in a hard rock face.

Before a charge can be inserted into a bore in the rock face it must first be primed by inserting a detonator into the charge. However, conventional methods of inserting the detonator into a charge are done by hand and there is a risk of premature detonation which can result in personal injury or even death. This primed charge is then inserted into the rock face until it reaches the limit of the bore. The primed charge is packed and sealed into the bore with material issued or whatever material is available. On completion of packing and sealing, the charge can be detonated. The current methods of packing and sealing the primed charge into the rock face are inconsistent and time consuming.

To overcome these problems the device has two primary functions, to provide a safer method of accurately aligning and inserting the detonator into the explosive charge and a simple and efficient method of inserting and sealing the primed charge into a bore in the rock face.

The device is manufactured from bio-degradable materials making it a safer, environmentally friendly and cost effective alternative to current methods of explosive applications used in the hard rock mining environment.

The device will be produced in a range of sizes to accommodate the various sizes of explosive charge. For ease of production it is intended that the outer & inner sleeves be divided into shorter lengths and manufactured in the most appropriate method for that individual length of sleeve.

The device is made up of two sleeves, an outer and inner sleeve, the inner sleeve fitting inside the outer sleeve. The outer sleeved houses the charge and the inner sleeve houses the detonator and the means to grip and seal the device once inserted into the prepared bore in the rock face.

Varying depths of bore are accommodated by means of the sleeves sliding one inside the other until the extent of the bore is reached.

Page 2 The invention will now be described solely by way of example and with reference to the accompanying drawings in which: Fig.1 shows an explosive charge fitted with a charge cap inside an outer sleeve. View is sectioned through axis for clarity.

Fig. 2a shows a t-handle orientated and aligned with a plug.

Fig.2b shows a t-handle fitted to a plug. View is sectioned thro' the pivot lugs for clarity.

Fig.3a shows a detonator with detonator cord fitted, pushed through a detonator collar.

Fig.3b shows a detonator fitted into a detonator collar. View is sectioned through axis for clarity.

Fig.4a shows a t-handle and plug sub-assembly pushed through an inner sleeve and also shows a grip ring fitted over the inner sleeve expanding section. View is sectioned through axis for clarity.

Fig. 4b shows a t-handle and plug sub-assembly in an inner sleeve with the t-handle in the stowed position and also shows grip ring in position and detonator cord routed through the plug cord slot.

View is sectioned through axis for clarity.

Fig.4c shows a detonator and detonator collar sub-assembly in position at end of inner sleeve and detonator cord routed down the Inner sleeve. View is sectioned through axis for clarity.

Fig.5a shows inner sleeve sliding inside outer sleeve and detonator and collar sub-assembly aligning with charge cap fitted into end of explosive charge. View is sectioned through axis for clarity.

Fig.5b shows inner sleeve further inside the outer sleeve with the detonator in position through the explosive charge cap and inside the explosive charge. View is sectioned through axis for clarity.

Fig.5c shows the detonator and detonator collar fully home in the charge cap and the inner sleeve pushed further into the outer sleeve and over the charge cap. View is sectioned through axis for clarity.

Fig.6a shows inner sleeve sub-assembly fitted inside outer sleeve sub-assembly, explosive charge with detonator inserted, plug and t-handle sub-assembly in position with t-handle in stowed position, grip ring in position and the detonator cord fed through the plug and routed out of the cord slot and down as it would if inserted into a bore in the rock face. View is sectioned through axis for clarity.

Fig.6b shows the device in the rock face bore with flange of inner sleeve flush with rock face, t-handle and plug assembly pulled out to furthest extent and the grip ring squeezed against the rock face bore providing a seal. View is sectioned through axis for clarity.

Page 3 In Fig.l, a charge cap (B) is first be fitted into the end of a shaped explosive charge (A) before being inserted into an outer sleeve (C). Charge (A) is orientated such that the charge cap (B) is towards the open end of the outer sleeve (C).

In Fig.2a, a t-handle (G) is orientated such that the pivot lugs (Gi) are aligned with the location slots (El) and pivot holes (El) of a plug (E).

In Fig.2b, a t-handle (G) is fitted to a plug (E) so the plug pivot lugs (Gl) fit into the t-handle pivot holes (E2) (See Fig.2a for reference).

In Fig.3a a detonator (J) with detonator cord (I) fitted, is pushed through a detonator collar (K) ensuring correct orientation.

In Fig.3b a detonator (J) is fitted into a detonator collar (K) ensuring the detonator lipped feature (Jl) snaps into the detonator collar retention groove (Kl).

In Fig.4a, a grip ring (D) is pushed over an inner sleeve (F) and positioned over the expanding section (Fl). A t-handle and plug sub-assembly (H) is pushed through the inner sleeve (F) until the plug (E) engages with the grip ring (0).

In Fig.4b, a t-handle and plug assembly (H) is pushed through a inner sleeve (F) such that the t-handle (G) can rotate and engage with the inner sleeve stow slot (F2) and the plug stow groove (E5) engages with the grip ring (D). A detonator cord (I) from a detonator and detonator collar sub-assembly (L) is routed down the inner sleeve (F) and through the t-handle and plug sub assembly (H) until exiting through the plug cord slot (E3).

In Fig.4c, the slack of the detonator cord is taken up and the detonator and detonator collar sub-assembly (L) is fitted into the open end of the inner sleeve (F). The detonator and detonator collar (L) is retained in the inner sleeve (F) by the detonator collar retention feature (K2) gripping the inner sleeve retention features (F3) (See Fig.3b for reference).

In Fig.5a, an inner sleeve assembly (N) is fitted inside the outer sleeve assembly (M) such that the detonator (J) aligns with the charge cap funnel feature (Bl).

In Fig.5b, the inner sleeve assembly (N) is pushed further into the outer sleeve assembly (M) until the detonator collar cone feature (K3) fully engages with the detonator cap funnel feature (Bl) and the detonator (J) is pushed through the detonator cap (B) until fully home in end of charge (A).

Retention of the detonator cap (B) in the charge (A) is aided by the detonator cap grip features (B2). At this stage the device is ready for insertion into a prepared bore in a rock face.

In Fig.5c, the inner sleeve assembly (N) is pushed further into the outer sleeve assembly (M) until the retaining grip between the inner sleeve (F) and detonator collar (K) is broken allowing the inner sleeve (F) to slide over the charge cap (B). Sliding action between the inner sleeve (F) and the outer sleeve (C) is controlled by applying friction between the two parts, this is provided by the inner sleeve pip features (F4) acting on the outer sleeve step feature (C2).

In Fig.6a, an Explosive Charge Assembly Aid and Insertion Tool (0) consists of an Inner Sleeve Assy. (N) with Grip Ring fitted, fitting inside an Outer Sleeve Assy. (M) with primed Charge (A) fitted, a T-Handle & Plug Assy. (H) and a Detonator & Detonator Collar Sub-Assy. (L). Detonator Cord (I) is routed downwards and T-Handle (G) is engaged in Inner Sleeve Flange (F5).

In Fig.6b, the Inner Sleeve Flange (F5) is flush with the rock face (RF). The t-handle (G) is pulled sufficiently to draw the plug (E) through the inner sleeve expanding section (Fl) and squeeze the grip ring (D) against the rock face bore to seal the device in position. Detonator Cord (I) is routed down the rock face (RF).

Claims

Page 4 Claims 1. An explosive handling tool comprising alignment and insertion means for a detonator into a shaped explosive charge, insertion and sealing means of a primed charge into a prepared bore in a rock face, retention means for the primed charge, adjusting and damping means for tool length such that the inner sleeve slides into the outer sleeve and clamping means such as a tapered plug which can be pulled via a handle through the inner sleeve to engage with the expanding section of the inner sleeve forcing the grip ring around the inner sleeve to expand and provide clamping and sealing in the rock bore.
2. An explosive handling tool according to claim 1, in which the alignment and insertion means are provided by the inner and outer sleeves sliding together enabling the detonator to engage with the cap fitted to the charge retained at the blind end of the outer sleeve, the cap is such that when the detonator is forced through it, the portion of the cap inside the charge will open and allow the detonator to push through the cap and into the charge.
3. An explosive handling tool according to claim 1, in which the retention means comprise of internal features to grip and retain the charge.
4. An explosive handling tool according to claim 1, in which the length adjusting means is provided by the inner sleeve sliding inside the outer sleeve and damping means for the sliding adjustment is provided by the pips on the outer face of the inner sleeve acting with the stepped feature on the inside face of the outer sleeve.
5. An explosive handling tool according to claim 1, where a flexible grip ring is positioned over the expanding section of the inner sleeve causing the expanding section to contract and grip the tapered plug fitted in the inner sleeve, the clamping means is provided by the grip ring being expanded by the displacement of the tapered plug through the inner sleeve expanding section.
6. An explosive handling tool according to claim 5, in which the axial position of the tapered plug in the expanding section of the inner sleeve is controlled by the grooved features of the tapered plug acting with the expanding section of the inner sleeve which is contracted by the grip ring, the squeezing characteristics of the grip ring force the expanding section to contract and locate with the grooved features of the plug thus preventing the plug from being pushed back.
7. An explosive handling tool according to claim 1, in which the plug is pulled through the inner sleeve expanding section by the plug handle which when passed through the flange end of the inner sleeve can be stowed in the slot provided in the inner sleeve flange and locating the plug in the expanding section but not so it forces the grip ring to expand.
8. An explosive handling tool according to claim 1, in which the means to grip the tool in the rock bore is provided by pulling on the handle, drawing the plug further through the expanding section and expanding the grip ring sufficiently to clamp and seal the tool in the rock face bore.Amendments to the claims have been filed as follows Claims 1. An explosive handling tool comprising alignment and insertion means for a detonator into a shaped explosive charge, insertion and sealing means of a primed charge into a prepared bore in a rock face, retention means for the primed charge, adjusting and damping means for tool length such that an inner sleeve slides into an outer sleeve and clamping means of a tapered plug which can be pulled via a handle through the inner sleeve to engage with an expanding section of the inner sleeve forcing a grip ring around the expanding section of the inner sleeve to expand and provide clamping and sealing in the rock bore.2. An explosive handling tool according to claim 1, in which the alignment and insertion means are provided by the inner and outer sleeves sliding together enabling the detonator to engage with a cap fitted to the charge retained at a blind end of the outer sleeve, the cap is such that when the detonator is forced through it, the portion of the cap inside the charge will open and allow the detonator to push through the cap and into the charge.3. An explosive handling tool according to claim 1, in which the retention means comprise of internal features to grip and retain the charge.4. An explosive handling tool according to claim 1, in which a length adjusting means is provided by the inner sleeve sliding inside the outer sleeve and a damping means for the sliding adjustment is provided by a row of pips on the outer face of the inner sleeve acting with a Q stepped feature on the inside face of the outer sleeve.5. An explosive handling tool according to claim 1, where the grip ring is positioned over the expanding section of the inner sleeve causing the expanding section to contract and grip the Q tapered plug fitted in the inner sleeve, the clamping means is provided by the grip ring being expanded by the displacement of the tapered plug through the inner sleeve expanding section. 6. An explosive handling tool according to claim 5, in which the axial position of the tapered plug in the expanding section of the inner sleeve is controlled by a stepped, grooved feature of the tapered plug acting with the expanding section of the inner sleeve which is contracted by the grip ring, the squeezing characteristics of the grip ring force the expanding section to contract and locate with the stepped grooved feature of the tapered plug thus preventing the tapered plug from being pushed back.7. An explosive handling tool according to claim 1, in which the tapered plug is forced through the inner sleeve expanding section by pulling on the tapered plug handle which when passed through the flange end of the inner sleeve can be stowed in a slot provided in the inner sleeve flange and locating the tapered plug in the expanding section but not so it forces the grip ring to expand.8. An explosive handling tool according to claim 1, in which the means to grip the explosive handling tool in the rock bore is provided by pulling on the tapered plug handle, drawing the stepped, grooved feature of the tapered plug further through the expanding section and expanding the grip ring sufficiently to clamp and seal the tool in the rock face bore.