US3851416A

US3851416A - Device for cartridge chamber in cartridge tool

Info

Publication number: US3851416A
Application number: US00328922A
Authority: US
Inventors: P Engstrom; E Boye
Original assignee: Gunnebo Bruks AB
Current assignee: Gunnebo Industries AB
Priority date: 1973-01-03
Filing date: 1973-02-02
Publication date: 1974-12-03
Anticipated expiration: 1991-12-03

Abstract

A gun for firing nails, bolts, etc., by the force generated by detonating an explosive cartridge includes a firing mechanism with a striker pin for detonating the cartridge by operating the firing mechanism. The gun further comprises an automatic firing mechanism including a hole of circular cross section for receiving therein the shell of the cartridge and has a further hole of circular cross section matching the bottom flange of the cartridge shell. The first hole has at its inside a successively decreasing diameter so that a junction between this hole and a third hole is obtained. The third hole has a smaller diameter than the second hole. The decrease of the diameter of the second hole starts at the point at which crimping of the cartridge shell commences when the cartridge is inserted into the cartridge chamber.

Description

United States Patent [191 Engstriim et al. Dec. 3, 1974 [54] DEVICE FOR CARTRIDGE CHAMBER IN 3,319,862 5/1967 Nei horn 42/[ R CARTRIDGE TOOL 3,490,673 1/1970 Diehl 227/10 [73] Assignee: Gunnebo Bruks Aktiebolag,

Gunnebobruk, Sweden [22] Filed: Feb. 2, 1973 21] Appl. No.: 328,922

[30] Foreign Application Priority Data Jan. 3, 1973 Sweden 515/73 [52] U.S. Cl. 42/1 R, 227/10 [51] Int. Cl F4lc 3/00, B25c 1/14 [58] Field of Search 42/1 R, l M; 17/1 B;

[56] References Cited UNITED STATES PATENTS 2,922,185 H1960 Aitkcri et al. 17/1 B 3,061,833 11/1962 DcCaro 3,168,744 2/1965 Kvavla 42/1 R Inventors: Per lngemar Engstriim, Vastervis;

Erhard Rudolf Boye, Gunnebobruk, both of Sweden Primary Examiner-Benjamin A. Borchelt Assistant Examiner-C. T. Jordan Attorney, Agent, or Firm-Plane, Baxley & Spiecens 5 7 ABSTRACT A gun for firing nails, bolts, etc., by the force generated by detonating an explosive cartridge includes a firing mechanism with a striker pin for detonating the cartridge by operating the firing mechanism. The gun further comprises an automatic firing mechanism including a hole of circular cross section for receiving therein the shell of the cartridge and has a further hole of circular cross section matching the bottom flange of the cartridge shell. The first hole has at its inside a successively decreasing diameter so that a junction between this hole and a third hole is obtained. The third hole has a smaller diameter than the second hole. The decrease of the diameter of the second hole starts at the point at which crimping of the cartridge shell commences when the cartridge is inserted into the car tridge chamber.

2 Claims, 21 Drawing Figures PATENTEVLBEE 31m swarms SWEEI 0F 6 PATENTEL 553 31974 SHEH 5 BF 6 PATENTEL DEB 31974 DEVICE FOR CARTRIDGE CHAMBER IN CARTRIDGE TOOL The present invention relates to the arrangement of a cartridge chamber in a cartridge tool which appropriately contains an automatic cartridge case ejector consisting of a spring-actuated extractor arm. In order that the ejector shall function satisfactorily, and not slide past the flange of the cartridge case, it is essential that the cartridge be released from its contact surfaces in the cartridge chamber as easily as possible. Cartridge cases are usually provided with a certain surface coating which, due to the combustion heat and the gas pressure, tends to adhere to the inner surfaces of the cartridge chamber and thereby impedes the extraction of the cartridge case, The risk of adhesion is, of course, greatest at the mouth of the cartridge case, where the deformation and the increase in temperature are greatest.

A further drawback of certain cartridge chambers and short barrels is that the development of the gas and the opening of the cartridge case takes place so rapidly that there is not time for complete combustion of the powder, but this is blown out, which can involve soot problems and a lower degree of efficiency.

An object of the present invention isv to eliminate said drawbacks, through a special design of the cartridge chamber. The rear part of the cartridge chamber has then been given approximately the same inner diameter as the outer diameter of the cartridge case, but at approximately the point where the constriction of the cartridge in the form of the crimping of the envelope surface commences, a change in diameter commences, so that there will be a tapered hole. This hole thereafter again takes the form ofa cylindrical hole with a smaller diameter, through which the gases are conveyedQSaid tapered hole prevents the cartridge case from expanding completely under the influence of the gas pressure, whereby the contact surface between the crimped surface of the cartridge case and the inner surface of the cartridge chamber is considerably reduced, which greatly reduces the tendency towards adhesion. This tendency is further reduced by the tapered diameter junction being terminated in such a way that the uppermost part of the crimped envelope surface of the cartridge case is bent over the edge formed at the junction between the tapered and the cylindrical holes. The reduced exit diameter will then also to a certain extent delay the gas flow, and better combustion of the powder will then be obtained.

Further characteristic properties of the invention will be noted from the following claims.

In the following, a complete cartridge tool containing the present invention will be described, with reference to the accompanying drawings,

in which FIG. I shows a complete cartridge tool,

in which FIG. 2 shows where in said cartridge tool a cartridge case ejector is arranged,

in which FIGS. 3 and 4 show two illustrations demonstrating the cartridge case ejector in two different functioning positions,

in which FIGS. 5 and 6 show a snap arrangement for fixing a nail with guide washer in two different functioning positions,

in which FIGS. 7, 8 and 9 show a muzzle part with the surrounding sleeve of the cartridge tool,

in which FIGS. 10 and 11 show the front end of the cartridge tool,

in which FIGS. 12 and 13 show a cartridge chamber with a cartridge for the tool before and after the cartridge has been fired,

in which FIGS. 14 and 15 show the trigger mechanism in two different functioning positions,

in which FIGS. 16 and 17 show the coaction between a guide pin engaging in a groove in the barrel of the cartridge tool and the groove in two-different relative positrons,

in which FIGS. l8, l9 and 20 more completely show the coaction between the pin according to FIGS. 16 and 17 and a striker piston in three different relative positions, and

in which FIG. 21 shows how said pin is actuated transversally.

In FIGS. 1 and 2 the reference designation 1 shows a tool body section made in one piece of metal. This part has a handle part 2 and from the handle part there is a part 3 directed axially forwards, at the top of which there is a guide part 4 with a more or less cylindrical hole for guiding a barrel 68, so that this can move axially along the hole. To the right of the handle part 2 a housing 6 is arranged for a trigger mechanism 7. The housing is provided with-an axial hole, which is coaxial with the hole in the part 4. The part 8 between the guide part 4 and the housing 6 has the character of a cradle. A cross-section of the cradle shows that it has a semi-circular form and that the inner envelope surface of the cradle forms a joining envelope surface between the inner envelope surface of the guide part 4 and the inner envelope surface of the housing 6. In the guide part 4, the part 8 and the housing 6 a tubular cylinder lining 9 is arranged, which is cut away at the part 8 so that within the part 8 a cradle-like lining is formed. At' its front end the cylinder lining has a radial flange 10, directed outwards. The rear end of the cylinder lining protrudes outside the housing 6. The protruding part is provided with external threads 11. A casing 12 with internal threads 13 is screwed on to the threads 11. The handle part 2, at its rear end, is provided with acoherent member 14 which can be made of, for instance, some elastic material, such as rubber or plastic. The member 14 has such an extent that it also covers the casing 12 and part of the outer surface of the housing 6. The elastic material has the function of absorbing part of the recoil force. The coherentmember 14, of elastic material, is secured to the handle part2 with the aid of a threaded screw 15.

The firing mechanism consists of a cylindrical unit 16. The cylindrical unit 16 has a transversal hole 17. A bolt 18 is inserted in the hole 17. Between the inner end of the bolt and the bottom of the hole a spring 19 is arranged. The bolt 18 has a transversal hole 20, in which is inserted the front end of a striker pin member 21. At the top of the hole there is a catch for the striker pin member 21, which is put out of function when the bolt 18 moves rearwards. At its front end the striker pin member 21 has a striker pin 22. The left side of the hole 20 is delimited by a wall 23, provided with a hole 24, of appropriate size so that the striker pin 22 can be placed in the hole with a small portion protruding outside the left side of the wall 23. At its lower end the bolt 18 has a lug 25, which slides in an axial groove 26 in the cylinder lining 9. In this way the cylindrical unit 16, because of the lug 25, can move in the lining 9 only in part of it recessed so that a transversal contact surface 27 is formed. The recessed part has the character of a cylinder, and has been given the reference designation 28. One end of ahelical spring 29 bears against the contact surface 27. The other end of the spring bears against the transversal flange 30 of a member which forms said flange, and a tubular part 31. The tubular part 31 has a contact surface 32. The tubular part 31 forms a passage for the striker pin member 21, and at its rear end the striker pin member has a flange 33, which can be brought to bear against said contact surface 32. The striker pin member 21 is provided with a spring 34, one end of which bears against the left end of the striker pin member 21, and the other end against the inner wall of the casing 12. The tubular part 31 is encircled by three

rings

35, 36 and 37, which bear against the transversal flange 30 and the bottom of the casing 12. These three rings are of elastic material, and are capable of absorbing recoil forces.

At the upper end of the handle 2, an axial, more or less rectangular through hole 38 is arranged. The hole 38 emerges into a conventional trigger opening 39. The axial groove 26 emerges at the upper part of the through hole 38. In the groove a two-armed lever 41 is arranged, (see FIGS. 14 and 15), one end of which can move in the groove 26, so that a lug 42 arranged at the top of said one end 40 can coact with the lug 25 of the bolt 18. The two-armed lever 41 is arranged so that it can pivot around an axle 43, which is arranged in the handle part 2. The other end 44 of the two-armed lever 41, via an axle 45 has a two-armed arm 46 supported on it, with one arm 47 directed more or less downwards and an arm 48 which is more or less horizontal. The horizontal arm 48 is arranged in an axial groove 49 running through the two-armed lever 41. The arm 47 which is directed downwards has an oval groove 50. Through the hole there is a pin 51. The pin is arranged in a trigger 52. The thrigger is movable axially in the through hole 38, and has a more or less vertical hole 53 for the arm 47 which is directed downwards. At its rear end the trigger 53 has a hole 54, which extends more or less axially. One end ofa helical spring 55 bears against the bottom of the hole 54 and the other end of the spring bears against the bottom of a hole 56, arranged in the coherent member 14. The helical spring causes the trigger to be always in its front position, at the same time as the two-armed lever 41 is caused to be in its lower position.

In the cylindrical unit, as will be noted from FIG. 2, a groove 57 has been cut down from the envelope surface, which groove has an axial direction, so that an arm 58 can be placed in the groove 57. From the ends of the arm 58, two arms 59 and 60 extend, as will be noted from FIGS. 3 and 4. The last-mentioned two made. Part of one end of the helical spring 29 rests against said cut-down section. The arm 59 penetrates into a groove made in the striker pin member 21. The arm 59 is made with a point 66, which point is in contact with the front cross wall 67 of the groove 65,

so that the helical spring 29 will impart a moment directed forwards to the arm 58, so that the point 61 can snap in, in front of the front side of the flange 62.

A barrel 68 is arranged so that it can be displaced axially in the cylindrical lining 9 (see FIG. 1). At its rear end the barrel has a chamber 69, the front end of which emerges into a bore 70 of the barrel. At its front end the barrel 68 has internal threads 71, which coact with external threads 72 of a muzzle part 73, which has a bore 74 with a diameter substantially corresponding to the head 100 of a nail 99. At its front end the muzzle part 73 has a diameter junction, so that a bore 75 with a greater diameter is obtained, Le, a diameter corresponding to the diameter of a guide washer 101 for the nail 99 (see FIGS. 5 and 6). In the bore 70 a striker piston is arranged, which has a rear part 76 with a diameter corresponding to the diameter 70 of the bore and a front part 77 which is always inserted in the bore 74,

which part 77 has a diameter corresponding to the bore 74. The barrel 68 has a through axial groove 78 arranged in a vertical plane through the barrel 68. In the groove a spring actuated lug 79 (see FIGS. 1 and 18) is inserted, which limits the movement of the barrel 68 towards the left so that the lug 79 in one position can be in contact with the rear end wall 80 of the groove 78. In this position the rear end of the barrel 68 mainly coincides with the rear end of the guide part 4. The lug 79 moreover is inserted so far into the bore 70 that it can be made to come into contact with the more or less transversal bearing surface 81 of the rear part 76. In the front end of the bore 70 and in front of the lug 79 a ring.

82 of elastic material is arranged, and in front of this and in contact with the rear end of the ring there is a flange-like part 83 of a tubular part 84. The tubular part 84 has a groove 85 for the lug 79. The barrel 68 has a step on its underneath side at the groove 78, so that when the lug is completely inserted in the barrel 68, this can move rearwards but not forwards.

In the part which is directed forwards straight under the groove 78 in the barrel 68 an axial groove 86 is arranged, which emerges into a pocket 87. Above the groove 86 the lining 9 is provided with a through groove 86A, for which a number of through holes can be substituted. The pocket 87 is intended to be covered with a side cover or the like which, for instance, is fastened to the pivot 88. The pocket is also shown in FIGS. 10 and 11. The lining 9 has a peripheral bead 89, which has a more or less rectangular cross section. Between the outer envelope surface to the left of the peripheral head a ring-formed space 90 is arranged, which is limited by the inner envelope surface of the guide part 4. Around its outer envelope surface the lining has longitudinally extending axial ribs 91, originating from a point on the lining located between the ends 4 of the guide part. The axial ribs extend up to the front end of the guide part 4. The upper sides of the axial ribs are in contact with the inner envelope surface of the guide part 4. In this way the lining in the guide part 4 obtains a number of axial channels around its periphery in which the exhaust gases of the bolt gun are distributed. As the flange 10 is at a certain distance from the front end of the guide'part 4, an exhaust opening 92 for said channels is obtained. A space corresponding to the space 90 can be arranged between the front edge of the ribs 91 and said exhaust opening.

The. muzzle part 73 has a relatively shallow peripheral recess 93, as shown in FIGS. 5 and 6. In the left part of the muzzle part, which is not recessed, there is an axial, shallow groove 94, which extends to the left from the recess 93. In the front end of this groove, i.e., at its left end, there is a radial hole 95, in which a ball 96 is placed. The lower end of the hole is slightly constricted, so that the ball cannot leave the hole 95 and become lodged in the bore part 75. Around the muzzle part 73 and then at the recess 93 a peripheral band 97 is placed. From one edge of the band a tongue 98 extends to the left along the axial groove 94. The tongue then covers the hole 95, so that the ball cannot be dislodged upwards. The band 97 and the tongue 98 are of such material that the tongue always strives to press the ball 96 downwards. The function of the ball 96 is to snap aside at the insertion of a nail 99 with a nail head 100 and a guide washer 101 into the

bores

74 and 75 which are arranged one after the other. When the ball has snapped aside, the nail 99 is retained in the bore. The advantage of this design compared with other designs is that the recess in the front part of the muzzle part 73 will be considerably smaller, which gives the front part greater strength. When other designs are used for retaining the ball 96, substantially greater recesses have had to be made. The arrangement described for retaining the ball 96 can of course be applied generally at muzzle parts for any arbitrary bolt guns whatsoever.

The muzzle part 73 is encircled by a collar 102 consisting of a front part 103 and a rear part 104, which is also shown in FIGS. 7 9. The rear end 104 is intended to have its edge in contact with the flange 10. A certain portion ofthe front part of the muzzle part 73 then protrudes out in front of the front edge of the part 103. In order to release the safety of the bolt gun, the front end of the muzzle part must be pressed in to such an extent that its front part coincides with the front edge of the part 103. On its inner envelope surface the part 104 has two

radial flanges

105 and 106, directed inwards. These flanges have two surfaces facing each other, which are parallel with each other. A cross section through the flanges gives an internal hole with two straight parallel sides and two curved sides facing each other. On the muzzle part 73, there is a dice-shaped part 107 which forms a peripheral raised section in front of the external threads 72. The dice-shaped part 107 has four axial

flat surfaces

108, 109, 110 and 111. The

surfaces

108 and 110 are at a distance from each other which mainly corresponds to the distance between the inner edges of the

flange parts

105 and 106. The distance between the

surfaces

109 and 111 is the same. At the left end of the

surfaces

111 and 109, two

curved flanges

112 and 113 are arranged, the curvature then approximately corresponding to the internal diameter of the part 104. When the muzzle part 73 is inserted into the collar 102, the

flanges

112 and 113 must obtain the position shown in FIG. 8. When the

flanges

112 and 113 have passed the

flanges

105 and 106, and the dice-shaped part 107 is to the left of the

flanges

105 and 106 which are directed downwards, they can be turned 90. Thereafter the muzzle part 73 can be moved from contact through the

flanges

112 and 113 against the

flanges

105 and 106 to contact with the contact surface 114. Due to the existence of the

flanges

105 and 106 and to the surfaces 108 to 111 it is possible with the aid of the collar 102 to screw on the muzzle part 73 to the barrel 68. The collar 102 thus has three functions, viz. to serve as a cover, to serve as a member which determines how far the barrel 68 should be moved rearwards in order that. the safety device of the bolt guns shall be released, and to serve as a member with the aid of which the muzzle part 73 can be un' screwed from or screwed on the barrel 68. The collar cannot move the bolt gun or release the safety. In its rearmost position the collar leaves part of the front end of the muzzle part 73 uncovered. However, this part is not sufficient to provide a grip for a user. The collar 102 described can of course have applications also on bolt guns of types other than the present one.

At the rear end of the barrel 68 a cylindrical hole 115 is arranged for the flange 62 of a cartridge 63 with a cylindrical main body 117 and a front more or less conical and folded part 118. (see FIGS. 12 and 13). The main body 1 17 is placed in a cylindrical hole 1 19 which has a diameter mainly corresponding to the diameter of the cylindrical main body 117. The cylindrical hole 119 is followed to the left by a'conical hole 120 with an inner edge 116. The conical hole 120 thereafter goes over into a hole 121 for transmission of the powder gases developed from the cartridge when this has been initated. The taper of the conical hole and the length of the cylindrical hole have been chosen in such a way that when the cartridge has been initiated the front edge 122 of the conical hole will function as a breaking edge, which involves that the folded front part 118 will be transformed into a conical part 123 and a tubular part 124. In this way, the front part of the cartridge will not become jammed in the chamber, nor will any residue be deposited in the chamber 69, which can make the chamber tighter and thereby cause cartridges subsequently loaded to be jammed in the chamber. At the chamber 69 the barrel 68 has an axial groove, which is radial, so that the arm 60 can obtain the contact shown in FIG. 4. The design described of the cartridge chamber is not limited for use in the present type of bolt gun, but can have general application.

The previously described trigger mechanism has been described to a rather great extent, but not sufficiently, however, and therefore, in the following, the trigger mechanism will be described in more detail. (see FIGS. 14 and 15). The horizontal arm 48 can move in an axial groove 49 in the two-armed lever 41 and its free end can be caused to come into contact with the outer envelope surface of the casing 9. The appearance of the groove will perhaps best be noted from FIG. 2. The lug 25 for the bolt 18 has two oblique surfaces, which are transversal, and have the

reference designations

125 and 126. The inclination of the surfaces is max. In the longitudinal section the lug 25 has a dove-tail character. The lug 42 has an oblique front side surface 127 with an inclination of 80, for coaction with the side surface 126 of the lug 25. The other end 44 of the lever 41 has an oblique contact surface 128 for coaction with an oblique or chamfered surface 129 in the upper left-hand side of the through hole 53. When the trigger 52 is moved towards the left, the oblique contact surface 128 is caused to slide along the chamfer 129, which involves that the part 44 of the two-armed lever 41 obtains a movement upwards, at the same time as the end 40 of the lever obtains a movement downwards.

FIG. 16 shows the front part of the barrel 68 and also its axial groove 78 and the inserted lug 79. The lug 79 has a more or less rectangular cross section, and a width mainly corresponding to the width of the groove.

Outside the groove 78 the lug changes over into a part 130 which cannot enter into the groove 78. The part 130m appropriately be given a cylindrical form, and in the barrel 68 two

recesses

131 and 132 have been made on either side of the groove 78, and then in the outer envelope surface of the barrel. The purpose of this is to achieve a guide groove for the part 130. The part 130 thus fits in the groove formed by the recesses 13] and 132. At its left end the groove formed has an inclined cross wall 134, which involves that the part 130, when moving towards the left, can slide upwards on the inclined wall 134 and can be caused to come into direct contact with the outer envelope surface of the barrel. The groove formed by the

recesses

131 and 132 has a cross wall 133 to the right, which is at right angles to the axis of the barrel 68. This involves that when the part 130 moves to the right, the part is caused to come into contact with the cross wall 133, and has no possibility of sliding up on the envelope surface of the barrel. The contact of the part 130 against the cross wall 133 will be noted from FIG. 17. FIG. 18 shows how the part 130 is movably arranged in the transversal direction in a lining 135, which is arranged in part 3, in

a hole. The lining 135 is screwed into a hole in the tubular lining 9. At its bottom, the lining 135 has an end wall 136. At the bottom, the part 130 changes over into a more or less cylindrical journal formed part 137, which passes through a hole 138 in the end wall 136. The journal formed part 137 has its lower end supported'in a transversal grip part 139, and then by means of a shaft 140, which goes through the transversal grip part 139 and the journal formed part 137. The transversal grip part has two

grip surfaces

141 and 142, which will .be located on either side of the bolt gun, as shown in FIG. 1'. The grip part 139 is in contact with the outer side of the end wall 136. If one of the grip surfaces 141 and 142, for instance the grip surface 142, is actuated by a finger 143 (see FIG. 21) the part 130 will be caused to move downwards so far that the part 130 will leave the groove formed by the

recesses

131 and 132, i.e. the barrel 68 has the possibility of moving for,- wards until the lug 79 comes into contact with the end wall 80 of the groove 78. At said actuation, the portion of the grip part to the left of the shaft 140 will function as apivot for a lever formed by the grip part 139. The purpose of the spring 144 is to return the part 130 to its original position.

The ring of elastic material 82 and the tubular part 84 serve the purpose of braking up the forwards movement of the striker bolt 77, as the contact surface 81 comes into contact with the right end edge of the tubular part 84 (see FIG. The tubular part 84 also serves the purpose of protecting the lug 79 from being destroyed through the rear part 76. The

parts

82 and 84 can be used generally in bolt guns.

The bolt gun described above functions in the following way. It is assumed that through a depression of the transversal grip part 139 the barrel has had the possibility of moving so far to the left that the lug 79 is in contact with the end wall 80. In this situation the striker bolt 77 assumes its rear position in the bore 70. A cartridge 63 is now inserted in the chamber 69. The barrel 68 is thereafter moved towards the right end until the part 130 comes into contact with the end wall 133, as is clearly shown in FIGS. 17 and 18. A nail 99 with a nail head 100 and with a guide washer 101 is inserted in the

bores

74 and 75. In order that the nail with guide washer shall remain in place in the

bores

74 and 75 the guide washer for the nail must pass by a locking ball 96, which is actuated by a tongue 98, so that part of the ball penetrates into the bore 75. The tongue 98 is spring actuated. When the nail is inserted in the

bores

74 and 75, the ball 96 is caused to snap aside, against the spring actuation, when the guide washer passes by. When the guide washer has passed, the ball again falls down and blocks the movement of the guide washer towards the left. The nail is thereby retained in the bore, and is ready to be fired. It should be obvious that the nail can be inserted first and thereafter the cartridge.

In the situation described the barrel assumes such a position that the oblique surface 126 of the lug 25 is located in front of the oblique surface 127 of the lug 42. Thus, firing cannot take place. If the collar 104 has its rear end in contact with the flange 10, the muzzle part 74 is protruding so far from the front end of the collar as is required to position the lug 25 directly under the lug 42. If the front end of the muzzle part 73 is now pressed against the surface into which a nail is to be driven, against the action of the helical springs 29 and 34, the barrel 68 will move rearwards so that the left end surface 103 of the collar 102 will be caused to coincide with the left end surface of the muzzle part. The bolt gun is now ready to be fired, i.e., the lug 42 is located directly under the lug 25. When firing, the trigger 52 is moved to the right, against the action of the spring 55. The journal 51 of the trigger then moves the arm 47, which involves that the arm 47 pulls down the left part 44 of the lever 41, which involves that the righthand part 40 presses up the bolt 18 so far that the striker pin member 21 is released for a movement towardsthe left, and the striker pin 22 passes through the hole 24 and sets off the cartridge 63. Due to the lever system, very little force is required on the trigger 52 in order to move the bolt 18 which, for safety reasons, is actuated by a very powerful spring. When the firing has taken place, the spring 55 presses the trigger 52 towards the left. At this movement the oblique contact surface 128 will slide along the chamfered surface 129, which involves that the lever 41 is turned clockwise, so that the lug 42 ceases to coact with the lug 25. The trigger 52 with the arms is now ready for a new firing. At the initiation of the cartridge 63 the striker bolt 76 and its front part 77 will move towards the left, to drive in the nail 99 with the part 77. At the movement of the striker bolt towards the left, the bolt is caught up by the contact surface 81 at the right end of the tubular part 84. Because of the elastic ring 82, the bolt 76 is caught up gently. The exhaust gases from the cartridge 63 pass through the groove 78 and the groove 86A underneath in the lining 9 and the groove 86 in the part 3 to the pocket 87, where the gases make a loop-formed or vortex movement downwards and thereafter pass up to the left of the peripheral bead 89, after which they are given an axial direction forwards in the space between the outer envelope surface of the lining 9 and the inner envelope surface of the guide part 4. Owing to the existence of the axial ribs, the gases are distributed out into a number of channels, which emerge into the space 92 and thereafter out into the open air. Due to the passage through the channels, the part jets are phase shifted in relation to each other. When the gases pass through the pocket 87, the power residue is left in the pocket. This residue can be removed from the bolt gun when the cover on the pocket is removed. By distributing the gases to a number of channels, which are formed by the ribs, a silencing effect is obtained. Both the residue collecting pocket and the silencer can each be applied generally in bolt guns.

When the cartridge 63 is fired, a recoil occurs. Its effect is dampened by the member 14, which is of elastic material. The recoil is further dampened by the three

rings

35, 36 and 37, which are of elastic material.

When the nail has been driven in, the transversal grip part 139 is given a downward movement through a finger 143 through actuation downwards on either of the grip surfaces 141 or 142, and the cylindrical part 130 is then caused to leave the groove formed by the

recesses

131 and 132. The barrel 68 can then be moved towards the left, all the way to coming into contact with the end wall 80. This movement of the barrel towards the left can be obtained either by allowing the barrel to fall down of its own weight, or by giving the barrel a centrifugal force. The barrel can also be pulled out. At the movement of the barrel towards the left, the striker piston is retained in a stationary position in the bolt gun due to the lug 79. This involves that during the movement of the barrel towards the left a relative displacement between the striker piston and the barrel takes place, so that the striker piston with its bolt will be returned to its original position. When this has taken place, the bolt gun is loaded anew with cartridge and nail, and the barrel is returned to the position where the barrel and nail are ready for driving a new nail.

As previously mentioned, the purpose of the collar 104 is to protect the muzzle part 73 as well as to regulate the length of the distance which the barrel must be pushed rearwards in order to release the safety of the bolt gun. The muzzle part 73 is thus movable in relation to the collar 102. The collar 102 also has another property, which is that it can be used for screwing in the muzzle part 73 at the barrel 68, and this is possible as soon the dice-formed part 107 with two opposite flat surfaces is in contact with the corresponding surfaces front cross surface of the cylindrical unit 16. When the barrel then, at the actuation of the grip part 139, is given a movement forwards, the cartridge 63 will be retained by the point 61, and the cartridge case will then fall out from the gun, or can be removed by hand.

We claim:

1. In a cartridge tool including a barrel having a bore and a cartridge chamber for receiving crimped cartridges and communicating with the bore which axially guides a striker piston, the improvement comprising the cartridge chamber having three sections, a first cylindrical section for accommodating a cartridge, a second cylindrical section communicating with the bore, said second cylindrical section having a smaller diameter than said first cylindrical section and being displaced therefrom, and a third section connecting said first and second sections, said third section having a diameter which gradually decreases and having a length which is shorter than the length of the crimped portion of the crimped cartridge so that such crimped portion extends into said second section when the crimped cartridge is completely inserted in the chamber and the border of said second and third sections providing a breaking edge when the cartridge :ls fired whereby the part of the crimped portion forward of the breaking edge presses against said second cylindrical section and the remainer pivots away from the wall of said third section.

2. The cartridge tool of claim 1. wherein said third section is frusto-conical.

Claims

1. In a cartridge tool including a barrel having a bore and a cartridge chamber for receiving crimped cartridges and communicating with the bore which axially guides a striker piston, the improvement comprising the cartridge chamber having three sections, a first cylindrical section for accommodating a cartridge, a second cylindrical section communicating with the bore, said second cylindrical section having a smaller diameter than said first cylindrical section and being displaced therefrom, and a third section connecting said first and second sections, said third section having a diameter which gradually decreases and having a length which is shorter than the length of the crimped portion of the crimped cartridge so that such crimped portion extends into said second section when the crimped cartridge is completely inserted in the chamber and the border of said second and third sections providing a breaking edge when the cartridge is fired whereby the part of the crimped portion forward of the breaking edge presses against said second cylindrical section and the remainer pivots away from the wall of said third section.

2. The cartridge tool of claim 1 wherein said third section is frusto-conical.