TECHNICAL FIELD The invention relates to a cylinder bolt mechanism in a repeating rifle, comprising a receiver and a bolt with a bolt body, which mechanism can be closed and opened by a rectilinear movement of the bolt by means of a handle, wherein a bolt head in the front part of the bolt is caused to be rotated in order to close and to open the mechanism, respectively, by posit.oning radially directed lugs on the bolt head to positions between and in front of, respectively, inwardly directed studs in the receiver or located at the rear of a locking chamber.

PRIOR ART

Cylinder bolt mechanisms of the above mentioned type, which are manouvered by a rectilinear movement of a handle, are known since very long. An early design is described e.g. in the Swedish patent No. 748, which was published as early as in 1886. This patent emphasizes the fundamental advantage of the rectilinear movement of the handle as compared to the traditional turning movement, namely the increased speed of the repeating movement and also a better shooting precision by the fact that the marksman or hunter need not take down the rifle from his shoulder. However, the mechanism described in SE 748 was very incomplete from a technical point of view and could not prevent that the technical development came to be dominated by mechanisms such as Mauser's system and similar systems which use a turning movement of the handle. Numeral straight-pull mechanisms, however, have been suggested over the years. In 1894 there was described in the German patent No. 84429 a cylinder mechanism with a bolt having, in the front of the bolt, lugs provided to be moved into a locking chamber in the receiver, where the lugs were rotated by means of threads on the bolt, such that the mechanism was locked in the locking chamber. In the German patent No. 135870, which was published in 1900, this principle was further developed. The bolt now was provided with a rotatable bolt head. The design of the mechanism, however, was such that it certainly

would have caused serious manufacturing problems, in spite of the fact that many necessary details, which further would complicate the manu¬ facturing, were not included in the design. A more complete straight pull action system is disclosed in my U.S. patent No. 4,672,762, but nor this one has made any break-through, mainly because also this one was too expensive to manufacture.

BRIEF DESCRIPTION OF THE INVENTION

The purpose of the invention therefore is to provide an improved cylinder bolt mechanism in a repeating rifle, which mechanism can be opened by a rectilinear movement of the bolt, i.e. a so called straight-pull action, wherein superior technical features are combined with a good manufacturing economy.

These and other objects according to a first aspect of the invention may be achieved therein that a hammer and a main spring are provided in the trigger mechanism and that the main spring is provided to be able to act on the hammer, so that the hammer when trigging the rifle will hit against a firing pin in the bolt by rotation of the hammer from a starting position, in which the hammer is cocked and located under the bolt and mainly in the trigger mechanism, to a released firing position in which at least part of the hammer is located within the region of the bolt.

According to a second aspect of the invention the said and other objects may be achieved therein that a rotational unit comprising said bolt head, which rotational unit is rotatably but not axially moveable relative to the bolt body, and a cocking unit, which is axially but not rotatably moveable relative to the bolt body, are provided mainly in the bolt body, that the handle is part of or is connected to the cocking unit, that a rear part of the rotational unit is telescoped into a sleeve- shaped front portion of the cocking unit, that either the said rear portion of the rotational unit has an outer helical groove, or that the sleeve-shaped front portion of the cocking unit has an inner helical groove, and

that a force transmission drive member extends from the region of the sleeve-shaped front portion of the cocking member or from the rear part of the rotational unit into said helical groove in the rotational unit or in the sleeve-shaped front part of the cocking unit, respectively, so that a upon axial movement of the cocking unit relative to the rota¬ tional unit, the rotational unit is rotated relative to the cocking unit and to the bolt body.

According to a third aspect of the invention the said and other objects of the invention may be achieved therein that the bolt comprises front members, including the said bolt head, which are rotatable about the centre axis of the cylinder mechanism, and rear members, which are axially moveable relative to the said front members by means of the handle, that one of said front and rear members is provided with a helical groove, and that in said groove in one of said members there is provided a free drive member in the form of a spherical ball which extends into a hole or recess in the other of said front and rear members, which ball by engagement with the helical groove, upon axial movement of the rear members relative to the front elements, is caused to rotate said front members.

As a result of any of the above mentioned aspects of the invention it is a feature of the invention that major part can be manufactured from standard tubular work pieces and this concerns at least the receiver and the bolt body as well as major parts of the rotational unit and the cocking unit, a feature which significantly facilitates the manufacturing of the cylinder bolt mechanism and makes the production economical. Preferably it is also a characteristic feature of the invention that substantial parts of at least the receiver and of the bolt body and preferably also substantial parts of the rotational unit and of the cocking unit, have the shape of cylindrical tubes.

Further aspects, advantages and features of the invention will be apparent from the appending claims and from the following description of a preferred embodiment.

BRIEF DESCRIPTION OF DRAWINGS

In the following description of a preferred embodiment, reference will be made to the accompanying drawings, in which

Fig. 1 is a perspective view of the bolt according to the preferred embodiment;

Fig. 2 is a side view of the receiver, partly in section;

Fig. 3 is a cross section of the receiver along he line III-III in Fig. 2;

Fig. 4 shows a vertical section through the reciever and the bolt along the centre axis thereof and the trigger mechanism in a side elevation thereof;

Fig. 5 shows the cylindrical bolt mechanism in a position where the rifle is opened;

Fig. 6 shows the bolt body from underneath;

Fig. 7 is a side view of the bolt body;

Fig. 8 is a side view of a bolt neck forming part of the rotational unit;

Fig. 9 shows the bolt neck along the line IX-IX in Fig. 8;

Fig. 10 shows a cocking sleeve forming part of the cocking unit, from below;

Fig. 11 is a longitudinal, horisontal section through an end piece forming part of the cocking unit;

Fig. 11a is a top view of an anti-rotation latch included in the end piece shown in Fig. 11;

Fig. lib is a vertical section through the rotation latch along the line Xlb-XIb in Fig. 11a;

Fig. lie is a side view of the rotation latch along the line XIc-XIc in Fig. 11a;

Fig. 12 is a top view of the trigger mechanism;

Fig. 13 is a top view of the housing in which the various parts of the trigger mechanism are arranged;

Fig. 14 is a side view of the same housing along a line XIV-XIV in Fig. 13;

Fig. 15 shows the interior of the trigger mechanism;

Fig. 16 is a perspective view of the main spring included in the trigger mechanism;

Fig. 17 is a longitudinal cross section through a hammer included in the trigger mechanism;

Fig. 18 is a side view of a sear included in the trigger mechanism;

Fig. 19 is an end view of the sear along the line XIX-XIX in Fig. 18; and

Fig. 20 is a longitudinal section through a safety catch included in the trigger mechanism.

DESCRIPTION OF PREFERRED EMBODIMENT

The main parts of the bolt action system consist of a receiver 1 made from and substantially having the shape of a cylindrical tube; a barrel 2 threaded into the receiver in a manner known per se, said barrel having a cartridge chamber 3; a bolt 4; and a trigger mechansim generally designated 5. A locking ring 6 is clamped behind a locking

chamber 7 between the rear end of the barrel 2 and an angular flange in the receiver 1. The locking ring 6 is designed in a manner disclosed e.g. in my U.S. Patent No. 4 672 762, which is incorporated in this specification by reference.

A cartridge magazine 8 is detachably fastened under the receiver 1 in a manner known per se. The receiver 1 has a smooth cylindrical inner surface with a diameter corresponding to that of the bolt 4. In the right hand side of the rear part of the receiver 1 a guiding groove 9 for a bolt guide rib 74 is cut through the wall of the reciever. In the bottom part of the receiver there are fastening means for the trigger mechanism 5, which may be designed in a manner known per se, and a rectangular, elongated hole 10 on top of the trigger mechanism for a hammer 83. Further, a bolt stop 11, which is spring biased and designed in a manner known per se, is provided in and on the receiver. An ejection opening for empty cases has been designated 12, and an opening for the feeding of new cartridges has been designated 13.

The bolt 4 consists of three main parts, namely a cylindrical bolt body 18; a rotational unit 19 which is located mainly in the bolt body; and a cocking unit 20 which also is located mainly in the bolt body 18.

The bolt body 18 in principle consists of a circular-cylindrical pipe and is manufactured from such a circular-cylindrical pipe, the outer diameter of which corresponds to the inner diameter of the tubular receiver 1. In the front end, the bolt body is provided with three projecting claws 21, corresponding to three claw slots between three studs, directed radially inwards in the locking ring 6 forming a claw coupling in a manner known per se from my previously mentioned U.S.

Patent No. 4 672 762. In the rear end, a groove 22 is cut through the right hand wall of the bolt body for the said bolt guide rib 74 in the same way as the guiding groove 9 in receiver 1. In the upper surface of the groove 22, which surface lies slightly higher than the corre- sponding upper surface 129 of the guiding groove 9 in the receiver, there is a recess 23 in the form of a notch for an anti-rotation latch

131. In its bottom part, the bolt body has a rectangular, elongated hole 24 for the hammer 83 in the same way as the hole 10 in the receiver 1. On the outer, left hand side of the bolt body, there is a longitudinal bolt stop groove 25, which extends along the major part of the length of the bolt body 18, provided to engage the bolt stop 11 in the receiver, Fig. 3. By manually releasing the bolt stop 11, the bolt 4 can be completely removed rearwards out of the receiver. Two gas vent holes in the bolt body have been designated 27.

The rotational unit 19 consists of three main parts, namely a bolt head 28; a bolt neck 29; and a firing pin 30. The bolt head 28 and the bolt neck 29 are secured to each other by threads 31 to define an integrated unit, which is rotatable in the bolt body 18 but is prevented from moving axially in the bolt body 18 by a circlip 32. A pin 33 extends from a boring 34 in the bolt head 28 into a recess in the bolt body 29 to prevent the bolt head from being unscrewed from the bolt neck. The pin 33 is kept in place in the recess in the bolt neck and between the bolt neck and the bolt head by means of a spring 35 which in its other end abuts an ejector 36, which is secured by a screw 37 allowing the ejector 36 to move a short distance in the boring 34. By removing the screw 37, the ejector 36, and the spring 35, the pin 33 can be removed, whereupon the entire bolt can be deassambled. The bolt head 28 in its front end in a manner known per se is provided with three lugs 38 provided to cooperate with corre- sponding studs in the locking ring 6 in a manner known per se. An extractor designed in a manner known per se has been designated 39.

The lugs 38 of the bolt head 28 extends beyond the bolt body 18. The lugs 38 have an outer diameter which corresponds with the outer diameter of the bolt body 18 and with the inner diameter of the cylindrical receiver 1. Along the major part of its length, the rotational unit, however, i.e. the integrated unit consisting of the bolt head 28 and the bolt neck 29, however, has a diameter which correpsonds to the inner diameter of the bolt body 18, and in its rear part the bolt neck has a still smaller outer diameter. This rear part in this description is denomitated bolt neck shaft 40.

A central through-boring for the firing pin 30 extends through the entire rotational unit 19, wherein the firing pin has a central portion 41 having a larger diameter than the rest of the firing pin, said central portion 41 of the firing pin being accomodated in a corresponding part 42 of the through-boring in the bolt neck 29.

Between said central large diameter portion 41 of the firing pin 41 and an annular surface 43, which defines one end of the boring portion 42 in the bolt neck 29, there is provided a flat brass washer 44. The total axial length of the central firing pin portion 41 and the brass washer 44 is slightly less, about 1.5 mm, than the corresponding boring part 42 in the bolt neck 29, such that a gap 49 is formed in the front end of the boring portion 42 in the bolt neck 29. This gap 49 allows the firing pin 30 to move a distance corresponding to the short lenght of said gap 49, so that the firing pin point 45 may strike and fire the cartridge. A return spring for the firing pin 30 has been designated 46. The power of the return spring 46 is negligible as compared to the power of the main spring 84 which will be described in the following. Gas vent holes - not shown - are provided in the bolt neck 29 communicating with the gas vent holes 27 in the bolt body 18. Two recesses 48 (one on each side) are provided in the bolt neck 29, adjacent to the bolt neck shaft 40.

A groove 52 having a semi-cicrular cross section is provided on the outside of the bolt neck shaft. Starting from the front end, the groove 42 first has a straight axial portion 53, which has a length equal with the depth of the recesses 48 in the bolt neck 29. Thereafter follows a helical portion 54 which extends rearwards along the shaft 40, such that the groove 52 totally spans over an angle of 60°, Fig. 9. The total length of the groove 52, according to the embodiment, is 20 mm.

The cocking unit 20 consists of a cocking sleeve 57, an end piece 58 and a cylindrical key-lock 59. The key-lock may be designed in a manner which is known per se e.g. through my above mentioned U.S. Patent No. 4 672 762 and prevents unauthorized excess to the rifle.

The cocking sleeve 57 has a sleeve-shaped front portion 60 having a boring with the same diameter as the outer diameter of the bolt neck shaft 40. The sleeve-shaped portion 60 also has the same length as the shaft 40, which is rotatably and axially (telescopingly) movable in the sleeve-shaped portion 60.

A recess 61 is provided in the central part of the cocking sleeve 57. The recess 61 extends from the bottom part of the cocking sleeve up to a height above the centre axis of the bolt mechanism as is shown in Fig. 4. The breadth of the recess 61 in the cross direction is slightly greater than the thickness of the hammer 83. The recess 61 faces the holes 10 and 24 in the receiver 1 and in the bolt body 18, respectively, when the rifle is closed, Fig. 4. A partition-wall 63 is provided between the recess 61 and the boring 62 for the bolt neck shaft 40, and in the partition wall 63 there is a through-boring 64 for the firing pin 30 which extends through said boring 64 such that the rear end 65 of the firing pin 30 is located in the recess 61 in the cocking sleeve.

A through-hole 66 is provided in the wall of the sleeve-shaped front portion 60 of the cocking sleeve 57. The hole 66 has a radially directed centre axis and faces the straight portion 53 of the groove 52 in the bolt head shaft 40 when the rifle is closed. The thickness of the wall of the sleeve shaped front portion of the cocking sleeve 57 equals the depth of the groove 52 in the bolt neck shaft 40. The hole 66 in the sleeve-shaped portion 60 in other words has a length corresponding to the depth of the groove 52.

A spherical steel ball 68 is accomodated in the hole 66 and in the groove 52, such that half of the ball is located in the hole 66 and half of it in the groove 52. The ball may also be manufactured of any other suitable hard metal or of any suitable ceramic material. The ball 68 is completely spherical and has the same radius as the groove 52. It should be appreciated that the ball 66 is locked-up in the groove 52 and in the hole 66 by the encasing bolt body 18, when the bolt 4 is assembled.

Two projections (noses) 67 in the front end of the cocking sleeve 57 have the same shape as the two recesses 48 in the bolt neck 29 in order to be able to engage and be accomodated in said recesses.

The end piece 58 is connected to the rear part 71 of the cocking sleeve 57 by means of screws. The screws have not been shown, but the screw holes have been designated 72, 73 in Fig. 11. The end piece 58 further, on its right hand side, has a bolt guide rib 74 extending in the axial direction. The thickness of the bolt guide rib 74, in a direction perpendicular to the plane of the paper (with reference to Fig .11), closely corresponds with the breadth 9 of the groove in the receiver 1. The length of the rib 74 corresponds with the length of the groove 9, such that the rib 74 can be moved into the bottom of groove 9. The guiding rib 74 in cooperation with groove 9 prevents the cocking unit from rotating relative to the receiver and consequently also relative to the bolt head, since the bolt head is prevented from rotating relative to the receiver by means of the bolt stop groove 25 and the bolt stop 11. The groove 9 at the same time serves as a complementary guiding of the bolt 4. A rounded recess 128 is provided in the upper wall 129 of groove 9.

The guiding rib 74 in the front end thereof has a lateral elongation 75, which forms part of a handle 76 which is bent downwards.

An oval recess 77 is provided in the end piece 58 of the cocking unit in the region of the bolt guide rib 74. The anti-rotation latch 78, which has the same oval cross section as the recess 77, is springingly accomodated in the said oval recess. The anti-rotation latch 78 is provided to cooperate on one hand with the notch 23 in the bolt body, and on the other hand with that part of the receiver which defines the upper wall 129 of the groove 9 in the receiver, and also with the upper/rear edge 130 of the receiver 1. Further, when the rifle is closed, the latch 78 is provided to cooperate with the rounded recess 128 in the front part of the groove 9.

For the cooperation with the notch 23 in the bolt body, the inner half of the upper end portion of the anti-rotation latch 78 is tapered like a wedge 131, which slopes rearwards, Fig. lie. The tapered portion 131 does not extend beyond the ^' outer side of the bolt body. For the said cooperation with the wall 129 and with the rear edge 130 of the receiver, an aslo with the rounded recess 128 in the front part of the groove 9, the outer half 132 of the upper end portion of the anti- rotation latch 78 is rounded on the front and on the rear part thereof such that it has the substantial shape of a half cylinder. A compression spring acting on the anti-rotation latch 78 in the bottom of the oval recess 77 is designated 133.

The trigger mechanism 5 now shall be explained with reference to Fig. 4 and to Fig. 12-20. The main parts shown in Fig. 4 consist of a housing 80 which is recessed in the stock of the rifle (not shown), a safety lever 81, a trigger 82, a hammer 83 and a main spring 84.

The housing 80 is fastened to the receiver 1 by means of a hook 85 and a screw (not shown). The main part 86 of the housing 80 consists of a one piece metal body, which is provided with a number of borings and recesses which are covered by a side-wall 87. A front recess for the hammer 83 is designated 88. This front recess 88 extends in the vertical direction through the housing 80. At the rear of and at a distance from the front recess 88 a second, a narrower recess in the form of a vertical groove 89 extends from a shelf 90 up to a horizontal groove 91. At the rear of said vertical recess or groove 89, a rear, vertical groove 92 extends from a bottom recess 93 for the trigger 82 up to the rear end of the horizontal groove 91.

The hammer 83 consists of a disc having the general shape of a circle sector ranging about 100°. The thickness of the hammer substantially corresponds with the breadth of the recess 61 in the cocking sleeve 57 and with the holes 10 and 24 in the bolt body 18 and in the receiver 1, respectively. The thickness also substantially corresponds with the depth of the front recess 88 in the housing 80. A straight striking and sliding surface is designated 94. Second straight edges are

designated 95, and a circular-arc-shaped surface is designated 96. A notch 97 is provided in the circular arc surface 96. When the hammer 83 is cocked, such that the main spring 84 is fully compressed, the edges 95 abut a front wall ^' 98 of the housing 80. A recess 99 for the main spring in the front part of the hammer is at the rear restricted by a rear wall 100.

The main spring 84, Fig. 16, can be described as a compression/torsion spring consisting of a helically wound spring wire having two legs 101, 102. The main spring is mounted on a pin 103 in the recess 99 and is compressed in the said recess 99 therein that one leg 101 abuts the front wall 98 of the housing 80 while the other leg 102 is pressed against the rear wall 100 of the recess 99.

The notch 97 in the circular arc surface 96 of the hammer 83 exhibits a straigt edge 104 in the direction towards the striking surface 94 and a bevelled surface 105 in the direction towards the main spring 84. The notch 97 designed in this way can accomodate the correspon¬ dingly shaped point portion 112 of a first slide, referred to as a sear 108, which is slidably accomodated in the horizontal groove 91. In its underside the sear 108 has a notch 109 and in its rear end it has a stepped recess 110, Fig. 18 and Fig. 19. The sear 108 is pressed against the hammer 83 by means of a sear spring 111.

A trigger slide 113 is movable in the first vertical groove 89 by means of the trigger 82. In its upper end, the trigger slide has a point portion 114 designed as the notch 109 in the sear 108. When the trigger 82 is in its non-trigging position, and the hammer 83 is cocked, the point portion 114 of the trigger slide 113 is pressed into the notch 109 in the sear 108 by means of a spring 115, securing the sear 108 in its position, such that the cocked hammer 83 is secured in its starting position with the main spring 84 fully compressed. An adjusting screw 116 is provided on the trigger 82 for the adjustment of the trigger. A lever 117 on the trigger 82 has a nose portion in engagement with a correspondingly shaped recess in the trigger slide 113. The trigger 82 can be turned about a trigger pin 118. A return spring for the trigger 82 is designated 119.

A safety catch 122, which also has the form of a slide, is movable in the rear vertical groove 92 between a lower non-catching position, Fig. 15, and an upper catching position (not shown) by means of the safety 81. The safety 81 can be turned about 45° about a turning axis 124, Fig. 4. In Fig. 4, the safety lever 81 is shown in its non- catching position. An elongated hole 125 in the safety lever then lies horizontally. A stud 126 on the safety cacth 122 is engaged in the elongated hole 125, more particularly in its left hand part, when the safety is brought to the non-catching position in which the hole 125 lies horizontally. In its upper end, the safety catch 122 has a projecting lip, which is off from catching engagement with the recess 110 in the sear 108 in the non-catching position.

The operation of the above described system now will be explained. When the rifle is loaded, closed and locked. The bolt 4 has the position in the receiver 1 which is shown in Fig. 4. The hammer 83 is cocked and the main spring 84 is maximally comressed. The safety 81 is in its rear, lower position, i.e. is turned about 45° anti-clockwise with reference to Fig. 4, turning the elongated hole 125 is turned obliquelly upwards. The projecting lip 127 on the safety catch 122 then is in engagement with the recess 110 on the sear 108, such that the sear can not be moved but is locked in the horizontal groove 91 with its point portion 112 in engagement in the notch 97 in the cocked hammer 83. The rifle in other words is locked by the safety catch, locking the cocked hammer 83.

When the rifle shall be fired, the safety 81 first is turned clockwise 45° about its turning axis 124 to the position shown in Fig. 4. By this turning movement, the stud 126 in the elongated hole 125 causes the safety catch 122 to slide downwards so that the projecting lip 127 is brought up from its engagement with the recess 110 in the rear end of the sear 108. The locking slide 122 now can not prevent the sear 108 from moving rearwards in the horizontal groove 91. This sliding movement, however, is prevented by the point portion 114 on the trigger slide 113, which is in engagement with the notch 109 in the sear 108.

The rifle now can be fired by means of the trigger 82. When the trigger 82 is turned clockwise about its trigger pm 118 to the trigging position shown in Fig. 12, the point portion 114 leaves the notch 109, releasing the sear 108. The unlocked and released sear 108 now will slide with its point portion 112 out of engagement with the notch 97 in the hammer 83 by the fact that the main spring 84 is pressing against the hammer 83, so that the bevelled surface 105 will slide against the correspondingly bpvelled surfacp 107 on the sear 108, with the result that the spar is prpssed out of pngagp ent with the notch 97. By action of the main spring 84, the hammer 83 there¬ after at a high rate will proceed clockwise about the axis 79, through the holes 24 and 10 in the receiver 1 and in the bolt body 4, respec¬ tively, up into the recess 61 in the cocking sleeve 57 to finally strike the rear end 65 of the firing pin 30 with full power with its striking surface 94. In the starting position, the front end of the firing pin point 45 lies in the same plane as the bolt face. By the strike from the hammer 83, the firing pin 30 is stroken forwards a distance corresponding to the narrow gap 49, i.e. according to the embodiment about 1.5 mm, so that the firing pin point 45 strikes the cartridge (not shown) wherein the cartridge is fired.

The rifle now shall be repeated. Initially, the anti-rotation latch 78 is non-operative as an anti-rotation latch per se, but is engaged by its rounded outer portion 132 in the rounded recess 128 in the front part of the bolt guide groove 9. This is possible because the upper wall of the bolt body groove 22 lies slightly above the corresponding receiver groove wall 129 giving sufficient space for the wedge-shaped inner portion 131 of latch 78 to spring up. By the engagement of the anti-rotation latch 78 in recess 128, accidental opening of the rifle is prevented. The necessary pulling force for the opening of the rifle can be adjusted by chosing a proper spring 133 or by adjusting the spring force.

The marksman now pulls the handle 76 as well as the entire cocking unit rearwards. In the initial phase of the pulling movement, the anti-rotation latch 78, with its outer roundPd portion 132 leaves the

rounded recess and is pressed down by receiver wall 129 above -the groove 9.

The non-operative anti-rotation latch 78 can not prevent any axial relative movement between the cocking unit 20 and the rotational unit 19. At the same time, during the initial phase of the rearwards movement of the cocking unit, the rotational unit 19 is prevented to be pulled rearwards by the fact that the lugs 38 on the bolt head are in engagement in front of corresponding studs on the locking ring 6. Also the bolt body 18 during this phase remains in its front position, as it is connected with the rotational unit by means of the circlip 32 which prevents any axial relative movements between the bolt body 18 and the rotational unit 19. This implies that the cocking unit 20 initially moves rearwards from the rotational unit 19, sliding in the bolt body 18. Therefore, during the initial phase of the rearward axial movement of the cocking unit 20 the projections 27 on the cocking sleeve 57 are pulled out from engagement with the recesses 48 in the bolt neck 29. At the same time the ball 68, which is locked up by the bolt body 18 in the hole 66 in the sleeve-shaped front portion 60 of the cocking sleeve, rolls a corresponding distance rearwards in the straight portion 53 in the groove 52 in the bolt neck shaft 40, cuasing no rotational movement of the rotational unit 19.

During the continued movement of the cocking unit 20 rearwards by means of the handle 76, the ball 68 runs into the helical portion 54 of the groove 52. The cocking unit 20 is prevented from rotating by the fact that the guiding cam 74 is engaged in the groove 9 in the receiver 1. Through force action between the cocking unit 20 and the rotational unit 19 via the ball 68, which is locked up in the hole 66, and the helical portion 54 of groove 52 the rotational unit 19 thus is caused to turn 60° about its centre axis relative to the cocking unit and also relative to the bolt body 18. This rotational movement is completed when the ball 68 reaches the rear end of the groove 52. At the same time the studs 38 on the bolt head 28 have been turned to the non-locking position in the locking chamber 7 in front of the locking ring 6, so that the whole bolt 4 now can be pulled rearwards in the

receiver 1 extracting the empty case to the position shown in Fig. 3, whereupon the extracted empty case is rejected through the rejection opening 12 and a new cartridge is brought up into the receiver from the magazine 8 to a position in front of the bolt 4.

When the whole bolt 4 is moved so far rearwards in the receiver 1, that the anti-rotation latch 78 is brought out from the engagement between the outer rounded portion 133 and the receiver wall 129 in the region of the groove 9, passing the rear edgp 130 of the receiver, the latch 78 can spring up such that the inner portion 131 of the anti-rotation latch 78 will be brought into locking engagement with the notch 23 in the bolt body. When the tapered portion 131 is brought into engagement with the notch 23, Fig. 3, the cocking unit 20 is prevented from any movement relative to the bolt body and consequently also relative to the rotational unit 19. The anti-rotation latch 78 now in other words is in operation, preventing any rotation of the rotational unit 19.

When the rifle is being opened in the manner above described, the hammer 83 is being cocked compressing the main spring 84. How this is carried out now will be explained. When the cartridge has been fired, the hammer 83 will remain with its surface 94 abutting the rear end 65 of the firing pin 30. When the cocking unit 20 is pulled rearwards - during the initial phase rearwards relative to the rotational unit and also relative to the bolt body 18 - the hammer 83 is not influenced at all during the first little piece of the rearward movement of the cocking unit 20. After a very short initial movement, however, the cocking sleeve 57 will engage the striking and sliding surface 94 of the hammer 83 with its partition wall 63. During the continued rearward movement of the cocking unit 20, the cocking unit 20 acts with a force against the hammer 83 - first by the rear side of the partition wall, thereafter by the lower edge 53 and finally by the lower portions 55 and 51 of the sleeve-shaped portion 60 of the cocking unit and of the bolt body 18 in front of the opening 24, respectively, so that the hammer 83 successively is turned anti¬ clockwise with reference to Fig. 12 to the position shown in Fig. 15.

During this turning movement the main spring 84 recessed in the hammer 83 will be increasingly compressed.

The force action against the striking and sliding surface 94 of the hammer by the partition wall 63 of the cocking unit, by the edge 56, by the bottom portion 55 of the cocking unit and by the bottom portion 51 of the bolt body, which is carried out by a sliding movement between the said parts and the surface 94 on the hammer 83, thus is performed during a comparatively long part of the rearward movement of the cocking unit 20 and of the bolt body 18, respectively. The work which is carried out results in a compression of the main spring 84. Since "power = force x the distance" only a comparatively small force is required for compressing the main spring and cocking the hammer, since the distance, during the passage of which the work is performed, is comparatively long.

It is therefore very easy to compress the main spring 84 and to cock the hammer 83 by coaction between the various parts of the bolt 4 and the hammer 83. This important achievement of the invention is the result in the first place of "the long cocking distance" described above and of the use of the free rolling ball 68 as a force transmission member between the cocking unit and the rotational unit.

When the main spring 84, has been fully compressed at the same time as the cocking of the hammer 83 has been completed, the point portion 112 of the sear 108 has been brought into engagement in the notch 97; the point portion 114 of the trigger slide 113 has been brought into engagement in the notch 109 in the sear 108; and the bolt 4 has been pulled so far back ir. the v^ooiver 1 that the empty case has been rejected, a new cartridge can be moved into the cartridge chamber 3.

The bolt 4 thereafter is moved forwards in the receiver 1 with the bolt stop 11 sliding in the bolt stop groove 25 in the outer surface of the bold body 18, Fig. 5. The anti-rotation latch 78 during the main part of this movement is operative, but when the outer part 132 of the anti-rotation latch 78 contacts the rear end 130 of the

receiver it will be pressed down and to slide in beneath the receiver wall 129 above the groove 9, such that the anti-rotation latch is released, i.e. is disengaged, which occurs at the same as the bolt head enters the locking chamber 7 with its studs 38 in front of the locking ring 6. Thus when the bolt head 28 has reached its end position in the locking chamber 7 and the claws 21 of the bolt body has run completely into the locking ring 6, the sleeve-shaped front portion of the cocking sleeve 57 of the cocking unit 20 is caused to move forwards on the bolt neck shaft 40. During this movement the ball 68 runs forwards in the groove 52 causing a rotation of the rotational unit back 60° so that the rifle is locked by engagement. of the lugs 38 of the bolt head in the locking chamber 7 in front of the studs on the locking ring. Finally the ball 68 is caused to roll along the final straight portion 53 of groove 52 by the cocking sleeve 57, wherein the projections 67 will slide into the recesses 48 in the bolt neck 29.

Not until these projections 67 are completety moved into the recesses 48, which they can not do until the rotational movement of the rotation has been completed, the front end of the firing pin point 45 will reach a position in plane with the bolt face, and the rounded outer part 132 of the latch 78 will enter the rounded recess 128 in the front part of the bolt guide groove 9 in receiver 1. At the same time the short gap 44 has been established, which gap is maintained by means of the return spring 46. Thereafter the new cartridge can be fired.

The rifle thus can be fired when the various parts of the system have taken the positions shown in Fig. 4. As an alternative, the rifle how can be locked. The safety 81 then is moved rearwards by turning it about 45° anti-clockwise (with reference to Fig. 4) about the safety pin, so that the hole 125 will be directed obliquely upwards. The safety catch 122 then is caused to move up in the groove 92 by the pin 126 so that the lip 127 on the safety catch will engage the recess 110 on the sear 108. The sear then can not be moved rearwards in the groove 91, which means that the sear 108 is locked and secured in the notch 97 in the hammer 83 by its point portion 94, which can not be pressed out of the notch 97 by means of the main spring 84, as this is prevented by the projecting lip 127 on the safety catch 122.

In case of accidental cartridge primer blasting, causing detonation gases to proceede rearwards, the gases will throw the firing pin with its central portion 41 like a piston against the brass washer 44 such that the washer may be compressed against the annular surface 43 and be widened through permanent deformation. The washer thus will work as a seal, which prevents the gases from proceeding further rearwards and instead escape through the vent holes (not shown) in the bolt neck 29 and through the vent holes 27 in the bolt body.