IL33100A

IL33100A - A caseless propellant cartridge with a charge of high compressiblity

Info

Publication number: IL33100A
Application number: IL33100A
Authority: IL
Original assignee: Dynamit Nobel Ag
Priority date: 1968-10-26
Filing date: 1969-09-30
Publication date: 1973-08-29
Also published as: ES372872A1; NL6914487A; GB1293803A; DE1805359A1; US3754510A; FI50939B; RO56417A; CA919432A; IL33100A0; AT305169B; FR2022313A1; FI50939C; JPS4840000B1; NO122738B; BE740681A; PL80569B1; DK125236B

Description

cartridge with a charge 2 he invention relates to caseless propellant cartridges for use with explosion powered working especially bolt setting comprising a body of propellant powder haVing a preferably in central position and preferably and a percussion priming charge in the In order avoid the splintering and breaking of the walls which ocours with cartridges having a case of a solid as a rule of which contains the pellant charge and priming it is known to use caseless propellant cartridges in which a percussion priming charge is disposed in a preferably central and preferably provided in cast or pressed body of pellant The invention relates to these caseless propellant cartridges and has the object so to improve them that by simple and inexpensive production methods a cartridge producing maximum security against unintentional ignition can be This is according to the in that the cartridge comprises a body of propellant powder which has a preferably in central and a percussion priming charge in the and in which the ignition is achieved by selective percussion applied within the limits of the the compressibility ratio of the propellant charge and the priming charge being in the range of lslO to 2a arrangement the result is achieved that when the percussion energy commonly employed in such instruments is the compression of the propellant oharge along the direction of the axis of the recess takes place substantially uniformly over the whole of the propellant charge but the compression of the priming charge nevertheless below the value required for its The high degree of security against unintentional achieved with the propellant charge according to the Invention results from the that for the ignition of the propellant charge the provision of a specially designed device is a primary a device having recesses the insertion of the propellant cartridge and the ignitio or priming pin which are so designed or so connected operatively with each that either the priming charge alone compressed between the priming pin and a solid counter surface beyond the degree of compression corresponding to the axial compression of the propellant charge by the conventional percussion energy used in the or that the priming charge is subjected to a further in addition to that caused by the conventional percussion energy In the device on the whole propellant which additional compression exceeds the value required for the Ignition and thus leads to A high degree of security against unintentional ignition also results from the fact that the forces ing in this device are greater than any forces which might act from the outside on the for example as a result of unintentional striking of the propellant charge with hammer or upon treading on a propellant charge has fallen on the and are thus also greater than the forces required for security In a preferred embodiment of the invention the recess in the propellant powder body completely filled with the primin This constitutes an advantage especially from point of view of since in this case it is possible to provide by of a thin layer varnish olosure at the front surfaces of the body of propellant which prevents the priming charge from falling The complete filling of the recess of the body of propellant charge with the priming Charge is also advantageous in that without having to adopt any special the priming charge is uniformly distributed a uniform height over the whole cross section of the recess even in the case of a very loose filling of the priming and is independent of the respective positio of the propellant charge body so that the required condition for ignition of the propellant charge over the whole in a uniform manner is Accordin specific requirements and to the materials used for the propellant charge body and the priming charge the minimum value of axial compression required for producing the ignition can be chosen or fixed at a lower or higher in order to give a maximum degree of security this value should be very and according to a further embodiment of the invention it should be at least 80 axial Such a high required degree of compression or compaction has at the same time the that the mechanical counter surface provided for insuring the clean percussion ignition acts as an it especially effective propellant Known materials or mixtures may be used for the percussion priming Preferably a mixture of tetrazine and nitrocellulose may be the percussion sensitivity of this mixture being controlled or determined to within very large limits by the corresponding variation of the proportion of the two The percussion sensitivity of this determined on the basis of is in each case at least equal or greater than the percussion sensitivity of each component by It is thus possible an advantageous to adapt the percussion sensitivity of the priming charge to the type of propellant charge As the propellant the invention proposes the use of nitrocellulose compressed to a highly compacted propellant powder According to another embodiment the body of propellant powder may be produced by extrusion from a example this process having the advantage of being simple and more it is also possible to manufacture the propellant charge body from a porous or propellant bound with an organic binder which does not leave any residue upon One embodiment of the invention is by way of in the accompanying drawings in 1 is a partial through a propellant 2 shows a device for ignition of the charge in the open and 3 shows the same device as in 2 in the closed The propellant charge represented in 1 consists of a ring shaped propellant charge body 1 produced by moulding or pressing and using a known organic binder burning without for example an epoxy and a priming charge 2 which completel fills the central bore of the ratio of the propellant and priming charge is and This ratio implies that upon use of a percussio energy normally applied in explosion powered working especially bolt setting upon sudden axial compression the propellant charge the priming charge is subjected only to a very small degree of which is not sufficient for so that a further compression of the priming charge is In order to prevent an unintentional falling out of the priming from body of propellant a powder foil 9 can be provided for covering the central bore of the rin or the front surfaces of the propellant body can be covered with a varnish made of an appropriate material burning without The parts 3 and 4 shown in 2 and are parts of a bolt setting tool partially which works the Into a recess 5 of the part 3 protrudes a pin 6 whose dimensions correspond to the of the bore or recess in the propellant powder ring 1 filled with the priming charge 2 as shown in The recess 5 which is used to accommodate the propellant charge corresponds to the dimensions A cylindrical projection 7 of the part 4 has dimensions which conform with those of the propellant charges used and of the recess 5 so when as shown in 3 both parts 3 and 4 are fitted into each a closed space 8 is In this space 8 the propellant powder body 1 of an inserted propellent powder charge is pressed when the two parts 3 and 4 are connected and in which after the priming charge 2 situated between the front surfaces of the projection 7 and the pin 6 is compressed to the smallest volume and thus compacted above the value required the ignition and is thus ignited the propellant charge is ignited itself and is converted into propellant gases of high pressure required for imparting the acceleration necessary for one of the two 8 insufficientOCRQuality

Claims

1. Propellant cartridge, for exploslonpowered' working tools, especially bolt setting tools, which comprises a body of propellant powder having a recess, preferably in central position, and a percussion priming charge in the recess and in which the ignition is achieved by selective percussion applied within the limits of the recess, wherein the compressibility ratio of the propellant powder and the priming charge is in the range of 1:10 to 1:1000.

2. A propellant cartridge according to Claim 1, wherein the recess in the propellant powder body is completely filled with the priming charge.

3. · propellant charge according to Claim 1 or 2, wherein the degree of compression required for ignition is only obtained after an axial compression of at least 80$.

4. A propellant cartridge aocording to any one of the preceding Claims, wherein the percussion-sensitive priming charge consists of an intimate mixture of tetrazine and nitrocellulose.

5. A propellant cartridge according to any of the preceding Claims, wherein the propellant powder body is maritkfactured from non-gellified highly compacted nltrooellulose.

6. A propellant cartridge according to any one of Claims 1 to 4, wherein the propellant powder body is manufactured from a gelllfied propellant powder by extrusion. 0 - 9 - 33100/2

7. - A propellant cartridge according to any one of Claims 1 to 4, wherein the propellant powder body is manufactured from a porous or non-porous propellant xnaterial bonded with an organic binder which does not leave any residue upon burning* For the Applicants RC/rb