CA1213764A - Process for the manufacture of one-piece plastic wads for cartridges - Google Patents
Process for the manufacture of one-piece plastic wads for cartridgesInfo
- Publication number
- CA1213764A CA1213764A CA000444490A CA444490A CA1213764A CA 1213764 A CA1213764 A CA 1213764A CA 000444490 A CA000444490 A CA 000444490A CA 444490 A CA444490 A CA 444490A CA 1213764 A CA1213764 A CA 1213764A
- Authority
- CA
- Canada
- Prior art keywords
- parison
- shot
- blow
- shot cup
- cartridges
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000000034 method Methods 0.000 title claims abstract description 18
- 239000004033 plastic Substances 0.000 title claims abstract description 17
- 229920003023 plastic Polymers 0.000 title claims abstract description 17
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 7
- 238000001125 extrusion Methods 0.000 claims abstract description 6
- 239000006096 absorbing agent Substances 0.000 claims description 10
- 238000000071 blow moulding Methods 0.000 claims description 10
- 230000035939 shock Effects 0.000 claims description 9
- 238000001816 cooling Methods 0.000 claims description 4
- 239000000843 powder Substances 0.000 claims description 4
- 239000012528 membrane Substances 0.000 claims description 2
- 238000007789 sealing Methods 0.000 claims description 2
- 238000002347 injection Methods 0.000 abstract description 2
- 239000007924 injection Substances 0.000 abstract description 2
- 239000007789 gas Substances 0.000 description 6
- 238000000465 moulding Methods 0.000 description 5
- 101100441413 Caenorhabditis elegans cup-15 gene Proteins 0.000 description 4
- QQKKFVXSQXUHPI-NBVRZTHBSA-N Acidissiminol epoxide Chemical compound O1C(C)(C)C1CC(O)C(/C)=C/COC(C=C1)=CC=C1CCNC(=O)C1=CC=CC=C1 QQKKFVXSQXUHPI-NBVRZTHBSA-N 0.000 description 1
- 241000283014 Dama Species 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- FCHAMFUEENBIDH-UHFFFAOYSA-N Severin Natural products CC1CCC2C(C)C3CCC4(O)C(CC5C4CC(O)C6CC(CCC56C)OC(=O)C)C3CN2C1 FCHAMFUEENBIDH-UHFFFAOYSA-N 0.000 description 1
- 238000010924 continuous production Methods 0.000 description 1
- 239000002826 coolant Substances 0.000 description 1
- 238000013016 damping Methods 0.000 description 1
- JNSGIVNNHKGGRU-JYRVWZFOSA-N diethoxyphosphinothioyl (2z)-2-(2-amino-1,3-thiazol-4-yl)-2-methoxyiminoacetate Chemical compound CCOP(=S)(OCC)OC(=O)C(=N/OC)\C1=CSC(N)=N1 JNSGIVNNHKGGRU-JYRVWZFOSA-N 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 210000004124 hock Anatomy 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- -1 polyethylene Polymers 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- BALXUFOVQVENIU-KXNXZCPBSA-N pseudoephedrine hydrochloride Chemical compound [H+].[Cl-].CN[C@@H](C)[C@@H](O)C1=CC=CC=C1 BALXUFOVQVENIU-KXNXZCPBSA-N 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 229920001169 thermoplastic Polymers 0.000 description 1
- 239000004416 thermosoftening plastic Substances 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F42—AMMUNITION; BLASTING
- F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
- F42B7/00—Shotgun ammunition
- F42B7/02—Cartridges, i.e. cases with propellant charge and missile
- F42B7/08—Wads, i.e. projectile or shot carrying devices, therefor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
- B29C49/02—Combined blow-moulding and manufacture of the preform or the parison
- B29C49/04—Extrusion blow-moulding
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
- B29C49/28—Blow-moulding apparatus
- B29C49/30—Blow-moulding apparatus having movable moulds or mould parts
- B29C49/38—Blow-moulding apparatus having movable moulds or mould parts mounted on movable endless supports
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
- B29C49/42—Component parts, details or accessories; Auxiliary operations
- B29C49/48—Moulds
- B29C49/50—Moulds having cutting or deflashing means
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C2793/00—Shaping techniques involving a cutting or machining operation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
- B29C49/42—Component parts, details or accessories; Auxiliary operations
- B29C49/58—Blowing means
- B29C49/60—Blow-needles
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)
- Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
Abstract
Abstract The one-piece plastic wad (13) used for the manufacture of shot cartridges is first preformed by extrusion by means of a die (1) to give a parison (6) which is then finally shaped in a blow mould (7a/7b) by means of compressed air. The compressed air is intro-duced by means of a needle (8) through the blow mould into the parison (6). This makes the hitherto required expensive injection mould unnecessary and, moreover, the process can be carried out continously.
(Figure 1)
(Figure 1)
Description
A proco~ for th~ ~nufacture of on~-piec2 pl~stlc ~ads for cartr1d ~s The pre~nt 1nvention rel~te~ to ~ pr~ces~ for the ~anufacture of oneop1~ce plastic ~ads for cartrid0es, 1n part1cular ~hot cartr~dges, each ~ad compr~sing a c~n which is ~o receive the po~der, a shot cup servin~ ~o receive the shot, and a ~hock absorber dispos2d bet~een the can and the shot cup. The invention also relates to the one~pieGe plastic ~ad manufactured by this process.
It is kno~n to those skilled ;n the art that such plastic ~ads, used for the production of cartridges, are manufactured by the ;nject;on-moulding process. Compared ~;th the parts to be manufactured, the mouLds requ;red for th;s purpose have to be relatively large and are correspondingly expensive. Moreover, the injection-~oulding process is time-consum;ng and cannot be carr;ed out continuously~
It is therefore the object of the present inven~
tion to propcse a process which not only considerably simplifies the process hitherto used, but aLso makes possible the use of substantially simpler moulds and con-tinuous production~ This novel process is characterized in that a parison i5 first made by extrusion and this parison is then given the desired final form by blow-moulding and is cooled.
According to another feature of this process, the parison made by extrusion is continuously moved during the blow-moulding step, and the blow mould surrounding the parison in the forming region is moved along with the parison flnd, after the end of the blow-moulding step and after cooling, is moved back again into its starting p 0 8 ition.
According to another feature of this process, pressurised gas is blown into the parison, introduced into the blow mould, at two points which are at a mutual distance in the axial direceion of the parison, in such a way that the connection between the powder can and the shot cup can be sealed gas-tight even duri.ng the blow-moulding step and subsequent sealing of these becomesunnecessary.
According to still another feature of this process a vacuum is applied to the outer surface of the parison located within the blow mould, and the parison is thus pressed against the contours of the blow mould by the gas pressure prevailing in the interior of the parison.
The one-piece plastic wad manufactured by this process is characterised in that the shock absorber in a virtually closed hGllow body filled with air.
.According to another feature of this plastic wad9 the connection between the can and the shot cup is interrupted by a gas-tight seal at least one point located between these two.
According to another feature of this plastic wad, the hollow body has one end face, serving as a yielding membrane, facing the can and one facing the shot cup, the end faces each being connected, respectively, to the can and the shot cup via one connecting element of smaller diameter, the connecting element adjacent to the can being wrlded ga~-tight.
~ n illu~tr~tive embod~ment of the subject of the ~nventton is d~scribed belo~, ~ith refer~nce to the attach~d drawing in which:
Figure 1 is a 5ectional representation of a de~ice used for extruding the par;son and for blo~-moulding the w~d, Figure 2 dia~rammatically illustrates a continuous manu-facturing process, and 0 Figures 3 and 4 sho~, in a diagrammat;c perspective vie~, t~o possible embodinlents of a ~ad manufactured by the process according to the invention~
Figure 1 sho~s an extrusion die ~hich is marked 1 as a whole and ~hich, in a kno~n manner, comprises a cylindrical cover 2, a mandrel (torpedo~ 3 coaxial to the cover and a die orifice 4. The mandrel 3 is fixed via radial ~ebs S to the inner wall of the die. The heated and thus plastic;sed materi~l passes under the action of a screw 3a to the die orifice 4 and emerges there in the form of a parison 6 wh;ch is still at a reLat;vely high temperature just belo~ the softening point.
As Figure 1 shows~ the front section of the mandrel 3 is prolonged in the form of a cylindrical extension 2b in such a ~ay that 1t guides the emerging parison 4 until the latter enters the region of a blo~ mould ~hich is marked 7 as a whole and ~hich has the ha~ched cross-section and is movably mounted and prov;ded ~ith drive means, in such a way that the t~o mould halves 7a/7b are pressed together in the d;rection of th@ arro~ and can also be d~ 6 ~
~p~r~ted a~n from one ano~1~r 1n the oppos~te direction.
Th~ two mould halves 7a~7b ~re closed as soon ss the parlson 6 has been moved through the en~ire Len~h of th~ mould. Immed'~ateLy after ~he mould has been closed, 5 compressed alr is blown v1a a needle 8 into the interior of the cavity H, so that the entire urface of the par;-son is laid ~galnst the inner swrfaces of the mould halYes 7a/7b. Since the mould is provided ~ith a cooling jacket 9, throu~h ~hich a coolant flo~s, the parison ~aterial ;s rap;dly cooled on contac~ ~ith ~he inner wall of the mould and, on solidification, assu~es the desired form g;ven by the contour of the mould halves~
The needle 8 is arranged and controlled in a bore in the mouLd half 7a in such a ~ay that, at a suitable lS moment, that is to say immediately after the mould has been closed, it pierces the parison b, a valve being opened and compressed air being admitt~d to the cavity H
through the needle 8.
If only one needle 8 is used~ the connecting points of the shot cup 15 and the can 14 to the shock absorber 22, ~hich are marked 16 and 17 in Figure 1, must remain open during the blo~moulding step and are subse-quently closed~ as necessary. To avoid this subsequent ~orking step~ a second needle 8a is preferably used ~hich is controlled synchronously with the firs~men~ioned needle 8 and ;s also ~ounted in a mouLd boreD at an axial distan~e from the former. If these t~o needles are used, the ~ould can then be shaped in such a ~ay that the Gon-nect;on point 16 of the st;ll plastic parison material i~ ~eld~d 0as-tight.
The ~nd ~ect~ons of the blow~moulded partO ~hich have been dama~ed by p;ersing ~lth th~ needle, are cut off~ as shown in Fi~ure 1.
s T~o pa~rs of blades 10 3nd 11 .are also movably arranged in the mould halves 7a/7b~ as shown ~n Figure 1, and they are controlled in such a way that they sever ~he ~ad at t~o po;nts after blo~-moulding and cooLing.
The pairs of blades 10, 11 can be located either, as 10 accord7ns to F;gure 1, ~ithin the blow mould or QutSide the blow mould. If severin~ is carr;ed out outs;de the mould~ a s;ngle blade suff;ces~ Other severing ele~ents, such as laser beams, ~ater ~ets~ saws and the llke can of course also be used~
Due to the contoursO ~hich can be seen in Figure 1~ of the mould halves 7a/7b, the resulting shape of the ~ad 13 is as sho~n in Figure 3. This ~ad thus has a cylindrical can 14 ~hich is to receive the po~der, a cyLindrical, somewhat Longer shot cup 15 for the shot and, between the can 14 and the shot cup 15~ a shock absorber 22~ This shock absorber 22 is a circuLar cylindrical~
virtually closed, air-filled hollo~ body ~hich has excel-lent properties ~ith respect to damping the recoil occurr ing on firing. The holloY body is connccted to the can 14 and ~he shot cup 15 via t~o tubular connecting elements 16, 17 respectively.
To ensure that a breakthrough of the po~der gases formed in the can 14 is prevented, the t~o ~ubular connec~
in~ ele~ents 16 and 17 are preferably sealed g2s-tigh~.
In ~ome ca5e8~ ho~ever~ 1t 3uf f i ces, ~s men~oned, to ~eal only one o~ these two conn~ct~n~ ele~ents ~as~ti~h~, ~h~l~t the other can have ~ throu~h-bore.
The mould shown in Figure 1 can be ~odified in v~rious ~ays by those skilled in the art~ Thus, 1t ~ould al50 be possible to make the hollow body type shock absorber 22 in a square shape or star shape ins~ead of a circular cyl1ndrical shape. It ~ould aLso be possible for the connecting elements 16 and 17 to have any desired hollo~ shape which can be obtained by blow-moulding. As Figure 4 also sho~s, a can 18 could also be connected to a shot cup 19 via a straight cylindrical connecting piece 20.
The blo~-rnouldin~ proce~s described is advan-ta~eously distinguished from the known injec~ion-moulding technol4gy, inasmuch as the involved~ relatively Large and expensive injection mould no~ becomes unnecessary and the production process can be speeded up considerabLy.
Moreover, as diagrammat;cally ;Llustrated ;n Figure 20 the manufacturing process can also be carried out con-t;nuously in a simple manner, in contrast to the existing technology. The nould halves 7a/7b are here arranged to be movable and are gu;ded by means of a drive on the periphery of continuous belts 12 runn;ng over rollers R~
in such a ~ay that the ~ould haLves move along ~ith the moved parison 6 on closing and subsequen~ly, after the end of the blow-moulding step, are l;fted off the parison and return again into their starting position. In Figure
It is kno~n to those skilled ;n the art that such plastic ~ads, used for the production of cartridges, are manufactured by the ;nject;on-moulding process. Compared ~;th the parts to be manufactured, the mouLds requ;red for th;s purpose have to be relatively large and are correspondingly expensive. Moreover, the injection-~oulding process is time-consum;ng and cannot be carr;ed out continuously~
It is therefore the object of the present inven~
tion to propcse a process which not only considerably simplifies the process hitherto used, but aLso makes possible the use of substantially simpler moulds and con-tinuous production~ This novel process is characterized in that a parison i5 first made by extrusion and this parison is then given the desired final form by blow-moulding and is cooled.
According to another feature of this process, the parison made by extrusion is continuously moved during the blow-moulding step, and the blow mould surrounding the parison in the forming region is moved along with the parison flnd, after the end of the blow-moulding step and after cooling, is moved back again into its starting p 0 8 ition.
According to another feature of this process, pressurised gas is blown into the parison, introduced into the blow mould, at two points which are at a mutual distance in the axial direceion of the parison, in such a way that the connection between the powder can and the shot cup can be sealed gas-tight even duri.ng the blow-moulding step and subsequent sealing of these becomesunnecessary.
According to still another feature of this process a vacuum is applied to the outer surface of the parison located within the blow mould, and the parison is thus pressed against the contours of the blow mould by the gas pressure prevailing in the interior of the parison.
The one-piece plastic wad manufactured by this process is characterised in that the shock absorber in a virtually closed hGllow body filled with air.
.According to another feature of this plastic wad9 the connection between the can and the shot cup is interrupted by a gas-tight seal at least one point located between these two.
According to another feature of this plastic wad, the hollow body has one end face, serving as a yielding membrane, facing the can and one facing the shot cup, the end faces each being connected, respectively, to the can and the shot cup via one connecting element of smaller diameter, the connecting element adjacent to the can being wrlded ga~-tight.
~ n illu~tr~tive embod~ment of the subject of the ~nventton is d~scribed belo~, ~ith refer~nce to the attach~d drawing in which:
Figure 1 is a 5ectional representation of a de~ice used for extruding the par;son and for blo~-moulding the w~d, Figure 2 dia~rammatically illustrates a continuous manu-facturing process, and 0 Figures 3 and 4 sho~, in a diagrammat;c perspective vie~, t~o possible embodinlents of a ~ad manufactured by the process according to the invention~
Figure 1 sho~s an extrusion die ~hich is marked 1 as a whole and ~hich, in a kno~n manner, comprises a cylindrical cover 2, a mandrel (torpedo~ 3 coaxial to the cover and a die orifice 4. The mandrel 3 is fixed via radial ~ebs S to the inner wall of the die. The heated and thus plastic;sed materi~l passes under the action of a screw 3a to the die orifice 4 and emerges there in the form of a parison 6 wh;ch is still at a reLat;vely high temperature just belo~ the softening point.
As Figure 1 shows~ the front section of the mandrel 3 is prolonged in the form of a cylindrical extension 2b in such a ~ay that 1t guides the emerging parison 4 until the latter enters the region of a blo~ mould ~hich is marked 7 as a whole and ~hich has the ha~ched cross-section and is movably mounted and prov;ded ~ith drive means, in such a way that the t~o mould halves 7a/7b are pressed together in the d;rection of th@ arro~ and can also be d~ 6 ~
~p~r~ted a~n from one ano~1~r 1n the oppos~te direction.
Th~ two mould halves 7a~7b ~re closed as soon ss the parlson 6 has been moved through the en~ire Len~h of th~ mould. Immed'~ateLy after ~he mould has been closed, 5 compressed alr is blown v1a a needle 8 into the interior of the cavity H, so that the entire urface of the par;-son is laid ~galnst the inner swrfaces of the mould halYes 7a/7b. Since the mould is provided ~ith a cooling jacket 9, throu~h ~hich a coolant flo~s, the parison ~aterial ;s rap;dly cooled on contac~ ~ith ~he inner wall of the mould and, on solidification, assu~es the desired form g;ven by the contour of the mould halves~
The needle 8 is arranged and controlled in a bore in the mouLd half 7a in such a ~ay that, at a suitable lS moment, that is to say immediately after the mould has been closed, it pierces the parison b, a valve being opened and compressed air being admitt~d to the cavity H
through the needle 8.
If only one needle 8 is used~ the connecting points of the shot cup 15 and the can 14 to the shock absorber 22, ~hich are marked 16 and 17 in Figure 1, must remain open during the blo~moulding step and are subse-quently closed~ as necessary. To avoid this subsequent ~orking step~ a second needle 8a is preferably used ~hich is controlled synchronously with the firs~men~ioned needle 8 and ;s also ~ounted in a mouLd boreD at an axial distan~e from the former. If these t~o needles are used, the ~ould can then be shaped in such a ~ay that the Gon-nect;on point 16 of the st;ll plastic parison material i~ ~eld~d 0as-tight.
The ~nd ~ect~ons of the blow~moulded partO ~hich have been dama~ed by p;ersing ~lth th~ needle, are cut off~ as shown in Fi~ure 1.
s T~o pa~rs of blades 10 3nd 11 .are also movably arranged in the mould halves 7a/7b~ as shown ~n Figure 1, and they are controlled in such a way that they sever ~he ~ad at t~o po;nts after blo~-moulding and cooLing.
The pairs of blades 10, 11 can be located either, as 10 accord7ns to F;gure 1, ~ithin the blow mould or QutSide the blow mould. If severin~ is carr;ed out outs;de the mould~ a s;ngle blade suff;ces~ Other severing ele~ents, such as laser beams, ~ater ~ets~ saws and the llke can of course also be used~
Due to the contoursO ~hich can be seen in Figure 1~ of the mould halves 7a/7b, the resulting shape of the ~ad 13 is as sho~n in Figure 3. This ~ad thus has a cylindrical can 14 ~hich is to receive the po~der, a cyLindrical, somewhat Longer shot cup 15 for the shot and, between the can 14 and the shot cup 15~ a shock absorber 22~ This shock absorber 22 is a circuLar cylindrical~
virtually closed, air-filled hollo~ body ~hich has excel-lent properties ~ith respect to damping the recoil occurr ing on firing. The holloY body is connccted to the can 14 and ~he shot cup 15 via t~o tubular connecting elements 16, 17 respectively.
To ensure that a breakthrough of the po~der gases formed in the can 14 is prevented, the t~o ~ubular connec~
in~ ele~ents 16 and 17 are preferably sealed g2s-tigh~.
In ~ome ca5e8~ ho~ever~ 1t 3uf f i ces, ~s men~oned, to ~eal only one o~ these two conn~ct~n~ ele~ents ~as~ti~h~, ~h~l~t the other can have ~ throu~h-bore.
The mould shown in Figure 1 can be ~odified in v~rious ~ays by those skilled in the art~ Thus, 1t ~ould al50 be possible to make the hollow body type shock absorber 22 in a square shape or star shape ins~ead of a circular cyl1ndrical shape. It ~ould aLso be possible for the connecting elements 16 and 17 to have any desired hollo~ shape which can be obtained by blow-moulding. As Figure 4 also sho~s, a can 18 could also be connected to a shot cup 19 via a straight cylindrical connecting piece 20.
The blo~-rnouldin~ proce~s described is advan-ta~eously distinguished from the known injec~ion-moulding technol4gy, inasmuch as the involved~ relatively Large and expensive injection mould no~ becomes unnecessary and the production process can be speeded up considerabLy.
Moreover, as diagrammat;cally ;Llustrated ;n Figure 20 the manufacturing process can also be carried out con-t;nuously in a simple manner, in contrast to the existing technology. The nould halves 7a/7b are here arranged to be movable and are gu;ded by means of a drive on the periphery of continuous belts 12 runn;ng over rollers R~
in such a ~ay that the ~ould haLves move along ~ith the moved parison 6 on closing and subsequen~ly, after the end of the blow-moulding step, are l;fted off the parison and return again into their starting position. In Figure
2, the startin~ position is marked I~ the closing position 7~'~
1~ markcd II and the ~nd pos1t~on~ from ~h1ch the rever~al of d1r~ct10n take3 pl~c~ m~rked III~
The expr~ss10n~ "blow-mould1n~" and "blow~mould;ng 3tep" used in the present CGnt@xt are to be understood ~n such a ~ay that they compr;se any manufactur;n0 proo cess operat;n~ with a d1fference in gas pressure~ In place of the provision of needles for applying pressurised gas, it ~ould, for example, also be possible to arrange a number of fine channels ;n the mould~ ~hich channels are connected to a vacuum source and end on the inner surface of the mould~ facing the parison. ~y applyin~ a vacuum, the plastic parison ~ouLd then be pressed against the contours of the mould, under the action of the gas pressure prevailing in the cavity.
The device described can operate vertically or horizontally.
The starting ~aterial used is a thermoplastic, preferably polyethylene.
1~ markcd II and the ~nd pos1t~on~ from ~h1ch the rever~al of d1r~ct10n take3 pl~c~ m~rked III~
The expr~ss10n~ "blow-mould1n~" and "blow~mould;ng 3tep" used in the present CGnt@xt are to be understood ~n such a ~ay that they compr;se any manufactur;n0 proo cess operat;n~ with a d1fference in gas pressure~ In place of the provision of needles for applying pressurised gas, it ~ould, for example, also be possible to arrange a number of fine channels ;n the mould~ ~hich channels are connected to a vacuum source and end on the inner surface of the mould~ facing the parison. ~y applyin~ a vacuum, the plastic parison ~ouLd then be pressed against the contours of the mould, under the action of the gas pressure prevailing in the cavity.
The device described can operate vertically or horizontally.
The starting ~aterial used is a thermoplastic, preferably polyethylene.
Claims (9)
1. Process for the manufacture of one-piece plastic wads for cartridges, in particular shot cartridges, each wad comprising a can which is to receive the powder, a shot cup serving to receive the shot, and a shock absorber disposed between the can and the shot cup, characterised in that a parison is first made by extrusion and this pari-son is then given the desired final form by blow-moulding and is cooled.
2. Process according to Claim 1, characterised in that the parison made by extrusion is continuously moved during the blow-moulding step, and the blow mould surround-ing the parison in the forming region is moved along with the parison and, after the end of the blow-moulding step and after cooling, is moved back again into its starting position.
3. Process according to one of Claims 1 and 2, characterised in that pressurised gas is blown into the parison, introduced into the blow mould, at two points which are at a mutual distance in the axial direction of the parison, in such a way that the connection between the powder can and the shot cup can be sealed gas-tight even during the blow-moulding step and subsequent sealing of these becomes unnecessary.
4. Process according to one of Claims 1 and 2, characterised in that a vacuum is applied to the outer surface of the parison located within the blow mould, and the parison is thus pressed against the contours of the blow mould by the gas pressure prevailing in the interior of the parison.
5. One-piece plastic wad for cartridges, in particular shot cartridges, manufactured by the process according to Claim 1, having a can which is to receive the powder, a shot cup serving to receive the shot, and a shock absorber disposed between the can and the shot cup, characterised in that the shock absorber is a virtually closed hollow body filled with air.
6. Plastic wad according to Claim 5, characterised in that the connection between the can and the shot cup is interrupted by a gas-tight seal at at least one point located between these two.
7. Plastic wad according to Claim 5, characterised in that the hollow body has one end face, serving as a yielding membrane, facing the can and one facing the shot cup, the end faces each being connected, respectively, to the can and the shot cup via one connecting element of smaller diameter, the connecting element adjacent to the can being welded gas-tight.
8. Plastic wad according to Claim 7, characterised in that the two connecting elements are tubular sections.
9. Plastic wad according to Claim 5 or 6, characterised in that the shock absorber is formed as a star-shaped hollow body.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH97/83A CH666221A5 (en) | 1983-01-07 | 1983-01-07 | METHOD FOR PRODUCING ONE-PIECE PLASTIC PLUGS FOR SCRAP CARTRIDGES. |
| CH97/83 | 1983-01-07 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1213764A true CA1213764A (en) | 1986-11-12 |
Family
ID=4179177
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000444490A Expired CA1213764A (en) | 1983-01-07 | 1983-12-30 | Process for the manufacture of one-piece plastic wads for cartridges |
Country Status (8)
| Country | Link |
|---|---|
| EP (1) | EP0113631A3 (en) |
| CA (1) | CA1213764A (en) |
| CH (1) | CH666221A5 (en) |
| ES (2) | ES528502A0 (en) |
| FI (1) | FI834714A (en) |
| GR (1) | GR81708B (en) |
| MA (1) | MA19995A1 (en) |
| PT (1) | PT77931B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NO337769B1 (en) * | 2014-10-14 | 2016-06-20 | Hexagon Raufoss As | Process and tools for producing a clamp-free liner |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU2002359806A1 (en) * | 2001-12-21 | 2003-07-15 | Rubbermaid Incorporated | Apparatus and method for forming discrete hollow parts |
| ES2363578T3 (en) | 2004-03-23 | 2011-08-09 | Nds Limited | PERSONALIZED MULTIMEDIA MESSAGE SYSTEM. |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3127837A (en) * | 1961-04-27 | 1964-04-07 | Driaire Inc | Shot shell construction |
| FR1384067A (en) * | 1963-11-13 | 1965-01-04 | Improvements to fillings for the manufacture of cartridges and the like | |
| DE1479603A1 (en) * | 1965-12-07 | 1970-07-23 | Pannenbecker H | Device for the continuous production of empty containers or containers that can be filled with material from thermoplastic plastic hoses |
| FR1467941A (en) * | 1965-12-23 | 1967-02-03 | Method and machine for manufacturing hollow molded plastic articles | |
| US3788224A (en) * | 1966-06-24 | 1974-01-29 | Federal Cartridge Corp | Nested wad column and method of shot shell loading |
| US3750580A (en) * | 1970-11-13 | 1973-08-07 | Asahi Chemical Ind | Wads for charging shot of shot gun |
| FR2294824A1 (en) * | 1974-12-18 | 1976-07-16 | Gruaz Eric | Split mould for plastic cartridge cases - for blank cartridges and ammunition for slaughter house pistols, industrial stud drivers, etc. |
| IT7821258V0 (en) * | 1978-03-22 | 1978-03-24 | Snia Viscosa | BORRAGE SYSTEM (BORRA) IN FLEXIBLY DEFORMABLE PLASTIC MATERIAL, FOR SHOTSHELLS, FOR HUNTING AND SHOOTING. |
-
1983
- 1983-01-07 CH CH97/83A patent/CH666221A5/en not_active IP Right Cessation
- 1983-12-21 FI FI834714A patent/FI834714A/en not_active Application Discontinuation
- 1983-12-23 EP EP83402531A patent/EP0113631A3/en not_active Withdrawn
- 1983-12-28 ES ES528502A patent/ES528502A0/en active Granted
- 1983-12-30 CA CA000444490A patent/CA1213764A/en not_active Expired
-
1984
- 1984-01-03 GR GR73424A patent/GR81708B/el unknown
- 1984-01-06 MA MA20216A patent/MA19995A1/en unknown
- 1984-01-06 PT PT77931A patent/PT77931B/en unknown
-
1985
- 1985-01-28 ES ES1985284180U patent/ES284180Y/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NO337769B1 (en) * | 2014-10-14 | 2016-06-20 | Hexagon Raufoss As | Process and tools for producing a clamp-free liner |
| US10486355B2 (en) | 2014-10-14 | 2019-11-26 | Hexagon Technology As | Method and equipment for production of a pinch line free liner |
Also Published As
| Publication number | Publication date |
|---|---|
| FI834714A (en) | 1984-07-08 |
| ES284180Y (en) | 1986-01-16 |
| GR81708B (en) | 1984-12-12 |
| CH666221A5 (en) | 1988-07-15 |
| ES8504014A1 (en) | 1985-04-16 |
| PT77931B (en) | 1986-04-10 |
| EP0113631A3 (en) | 1986-03-26 |
| ES528502A0 (en) | 1985-04-16 |
| MA19995A1 (en) | 1984-10-01 |
| ES284180U (en) | 1985-06-01 |
| PT77931A (en) | 1984-02-01 |
| EP0113631A2 (en) | 1984-07-18 |
| FI834714A0 (en) | 1983-12-21 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |