Historical Document · 1971
The H&K two-part bolt patent of Jauch and Meidel (priority 28 October 1967; issued 2 March 1971). The HK PSG1 dive cites it for the bolt head and carrier relationship.
‘United States Patent [111 3,566,745 [72] lnventors Stanly Jaucll [56] Weiden uber l-lorb; [21] [22] [45] [73] Herbert Meidel, Oberndorf, Germany Appl. No. 770,648 Filed Oct. 25, 1968 Patented Mar. 2, 1971 Assignee [32] Priority [33] [31] Heckler & Koch Gmbll Oberndorl' (Neckar), Germany Oct. 28, 1967 References Cited UNlTED STATES PATENTS 2,890,626 3,153,982 6/1959 10/1964 350,225 367,086 12/1960 3/1963 Amsler ....................... .. Seifried ...................... .. 89/187 89/194 FOREIGN PATENTS Switzerland ................ .. Switzerland ................ t. 89/180 89/194 Primary Examiner~ Benjamin A. Borchelt Germany Assistant Examiner—Charles T. Jordan I’; 15 78 392.3 Attorney-Craig, Antonelli, Stewart & Hill ABSTRACT: An automatic ?rearm, in particular a hand [54] AUTOMATIC FIREARM BIPARTITE SEMIRIGID BOLT 11 Claims, 5 Drawing Figs. [52] us. Cl ...................................................... .. 89/187, 42/16 [51] Int. Cl ....................................................... .. F4ld 1/00, [50] , Field of Search .......................................... .. F41d 3/00 42/16 —l6.5; 89/173, 187, 194, 196, l79—l83 ?rearm or small arm, with a semirigid bolt having a bolt head carrier provided with a camming piece and a bolt head disposed on the camming piece so as to be movable within cer tain limits in the longitudinal direction of the bolt. At two diametrically opposed points of the bolt, recesses are provided for accommodating locking members in the form of locking rollers which can be pushed outward by the camming piece to a point where they are free to leave the recesses of the bolt head in an outward direction and to enter into corresponding recesses in the barrel extension of the firearm. 71/ Patented Mafch 2, 1971 31,566,745 2 Sheets-Sheet 1 INVENTORY JT?/WI? JMICH Mmamr heme: BY ,, @lf 8 W’ ATTORNEYS Patented March 2, 1971 » 3,566,745 2 Sheets-Sheet I INVENTORS ‘ST/Mar J?ucu BY a“? 3M ATTORNEYS 3,566,745 ' l 2 AUTOMATIC FIREARM BIPARTITE SEMIRIGID BOLT Furthermore, the catch lever according to the invention may have a projection at one end, said projection engaging a recess in the other component part of the bolt and bottoming against one end of the recess when the bolt is in its unlocked The present invention relates to an automatic ?rearm, in particular a hand ?rearm or small arm, with a semirigid bolt 5 position‘, such that in this embodiment of the invention the consisting of a bolt head carrier provided with a wedge or camming piece and a bolt head which is so disposed on said camming piece as to be movable, within certain limits, in the longitudinal direction of the bolt and which at two diametri cally opposed points is provided with recesses accommodating locking members, in particular locking rollers, which can be pushed outward by the camming piece to a point where they are free to leave the recesses of the bolt head in an outward catch lever simultaneously serves as the connecting link which causes the bolt head to follow the recoil of the bolt head carri er and prevents the bolt head from sliding off the camming piece of the bolt head carrier. This obviates the need of locking studs or similar members previously used to prevent a separation of the bolt head from the bolt head carrier with the bolt in its mounted position, while permitting the bolt head to be displaced a certain amount with respect to the camming piece. The bolt according to the invention is thus further sim direction and to enter into corresponding recesses in the bar 15 pli?ed by designing the catch lever so as to form such a con rel extension of the ?rearm. In ?rearm with such bolts, the locking members, and in par ticular the locking rollers, are subject to forces exerted by the camming piece of the bolt head carrier which tend to push necting link. In a preferred embodiment of the invention, the catch lever is mounted in the bolt head carrier. Generally, the bolt head carrier affords more space for accommodating the catch lever said members in an outward direction even during the coun terrecoil of the bolt while the bolt head carrier is propelled by 20 than does the bolt head. In the vicinity of its front end, the catch lever is provided with a sawtooth-shaped nose, nose, the the recoil spring and advances the bolt head. The slide must, steep ?ank of which engages the rear end face of the bolt head therefore, be provided with runways for said members which with the bolt in the unlocked position and drops into a cor prevent the locking members from leaving the bolt head. These runways, apart from increasing the manufacturing costs 25 responding recess of the bolt head when the bolt is locked. In order to disengage the nose from the rear end face of the of the ?rearm, are subject to heavy wear, which adversely af bolt head, this embodiment of the invention provides for a fects the life of the ?rearm. A particularly grave disadvantage cam to be disposed near the front end of the catch lever, lies in the fact that in the extreme rear position of the bolt, laterally of the nose and extending in the same direction, said when the bolt is stopped an ?ung back in the forward direction, and when the bolt head hits a cartridge to be in— 30 cam cooperating with a ramp disposed in the barrel extension of the ?rearm. The ramp is followed by an indentation into serted into the barrel, the cammingpiece, the locking mem bers, and their guideways are subject to heavy impact loads. which the cam drops when the bolt is in the locking position, Said members must be of a very robust construction to thus providing an antirebound feature. ’ In a further embodiment of the invention, a spring-loaded withstand such impacts for a sufficiently long period of time. This is an essential disadvantage of the known automatic 35 pin which tends to force the two components of the bolt apart may be mounted in one of the two bolt components, especially ?rearms of the type described. in the bolt head carrier, in a manner permitting said pin to be It is the object of this invention to avoid these disad vantages. According to the invention, this objective is accom plished by pivotally mounting in one of the two parts compos ing the bolt a catch lever extending in the longitudinal displaced in the longitudinal direction. Irrespective of manu facturing tolerances, this pin ensures that under any operating conditions the bolt head and the bolt head carrier will be kept direction of the bolt, a nose on said catch lever engaging the rear end ofa shoulder on the other component part of the bolt apart far enough to enable the nose of the catch lever to en gage the rear end of the corresponding shoulder of the other when the latter is in the unlocked position, thus keeping the bolt component and to de?nitely keep the bolt components apart until the bolt again moves into the locking position. ing a control cam which is permanently connected to the slide 45 The design of the firearm according to the present invention and which diserigages the catch lever from the shoulder when is particularly suitable for pistols. When applied to pistols, the the bolt moves into the locking position. bolt head carrier may be rigidly fastened in the slide in a two component parts of the bolt spaced apart, and by provid The invention ensures that the two component parts of the manner known per se. bolt are being kept apart during both the recoil and the coun Further details and embodiments of the invention will terrecoil of the bolt so that the camming piece cannot exert 50 become apparent from the following speci?cation, in which upon the locking members any forces acting in an outward the invention will be described and explained in greater detail, direction. Consequently, there is no need of providing the reference being made to an embodiment shown by way of ex ?rearm with any special runways for the locking members. It ample in the accompanying drawing. In other embodiments of suf?ces to design the barrel extension in such manner that in the invention, the features apparent from the speci?cation and case any locking members should have left the bolt head such 55 the drawing may be applied separately or in any desired com locking members will be returned into said bolt head before bination. In the accompanying drawing: said head moves into its locking position. The above explana FIG. 1 is a vertical longitudinal section of a pistol bolt ac tions show that the application of the catch lever according to cording to the invention in the counterrecoil position, drawn the present invention simpli?es the ?rearm and increases its on a larger scale, life. When the bolt moves into the locking position, an ordina 60 FIG. 2 shows the arrangement according to FIG. 1 in the . ry control cam disengages the catch lever from the shoulder so locking position, , that the bolt head carrier can move against the bolt head when the latter has arrived at the rear end of the barrel and, with the FIG. 3 is a top view of the barrel extension at the rear end of the barrel with a horizontal section through the head of the en aid of the camming piece, force the locking members, in a tering bolt and an exterior view of the forward portion of the known manner, into corresponding recesses of the barrel ex 65 bolt head carrier, tension of the ?rearm, thus achieving the desired semirigid locking feature. FIG. 4 is a side elevation of the barrel extension according to FIG. 3 in the direction of the arrow IV together with the In a preferred embodiment of the invention, the control carn, which is permanently connected to the slide, is provided catch lever prior to moving into the locking position, and FIG. 5 is a side elevation similar to FIG. 4 but with the catch with an indentation which engages a projection of the catch 70 lever in a position corresponding to the locking position of the lever when the bolt is in its locked position. The antirebound bolt. feature of the catch lever according to the present invention As is apparent from FIG. 1, the bolt shown in the drawing obviates the need for supplementary masses or similar mea sures intended to prevent a rebound of the bolt, simultane consists of a bolt head carrier 1 and a bolt head 2 disposed so as to be movable with respect to said bolt head carrier. The 75 bolt head carrier l is formed by a metal block secured, in a ously ensuring extreme functional safety of the ?rearm. 3 3,566,745 4 manner known per se, in a slide 3 of U-shaped cross section, said slide being supported so as to be movable in the longitu dinal direction of the pistol, as usual. The bolt head carrier 1 is er can approach the bolt head, which has meanwhile reached provided with a rectangular forward projection 4 of reduced the recesses 5 of the boltvhead in an outward direction and cross section on which the bolt head 2 is disposed so as to be into corresponding recesses 27 of the barrel extension 25 by slidable in the longitudinal direction. The projection 4 forms a wedge or camming piece for the control of two locking rollers 6 disposed in recesses 5 of the bolt head (FIG. 3). The end face of the camming piece 4 is provided with bevels 7 which cooperate .with said locking rol lers 6. A catch lever 9 is pivotally supported in a recess 8 of the the locking position. The approach of the bolt head carrier causes the locking rollers 6 in the bolt head to be forced out of means of the bevels 7 at the front end of the camming piece 4. This describes the method of accomplishing the known semirigid locking feature of the bolt. In addition, however, the cam 23 on the catch lever 9 drops into the recess 26 of the barrel extension during the counterrecoil of the bolt head car rier 1, as shown in FIG. 5. Simultaneously, the nose 12 drops into the recess 22 of the bolt head, as shown in FIG. 2. in this manner, rebound of the bolt head carrier 1, said catch lever extending in the longitu bolt head carrier 1 is positively prevented. dinal direction of said bolt head carrier and projecting from it After the shot has been ?red, the bolt head and the bolt with its front end in the forward direction. The front end of the head carrier recoil under the action of the gun powder gases catch lever is provided with a projection 10 which engages a and the bolt head and the bolt head carrier move apart again. corresponding recess 11 of the bolt head. Aft of said projec The separating motion is assisted by the spring-loaded pin 18 tion, and with spaced relation to it, the catch lever is provided which pushes the bolt head 2 away from the bolt head carrier with a sawtooth-shaped nose 12, the steep ?ank 13 of which 1 and ensures that the nose 12 of the catch lever 9, under the faces forward. With the bolt unlocked, said steep ?ank 13 of force of the spring 17 , can again engage the rear and face 14 said nose 12 is positioned behind the rear end face 14 of the of the bolt head 1. bolt head 2, thus keeping the bolt head carrier and the bolt It will be apparent that the present invention provides a very head separated by a predetermined ?xed distance. At the simple bolt which is secured against rebound and ensures that same time, the projection 10 locks behind a projection 15 25 the rear end of the barrel is properly locked at the moment the disposed in the recess 11 of. the bolt head 2, thus preventing shot is ?red and the locking members of which are subjected the bolt head 2 from sliding off the camming piece 4 of the to loads at the moment of ?ring the shot only while no loads of bolt head carrier 1. In order to keep the projection 10 and the any kind are acting on them for the rest of the time. This nose 12 of the catch lever 9 engaged with the bolt head, a heli results in substantial simpli?cations and considerably in cal compression spring 17 is disposed between the rear end 16 30 creases the life of such a ?rearm. In particular, the present in of the catch lever 9 and the bolt head carrier 1. vention, for the first time, enables such a bolt to be also ap Furthermore, a pin 18, whose end projecting from the front plied to pistols. end face of the bolt head carrier bottoms against the rear end We claim: face 14 of the bolt head 2, is slidably mounted in the bolt head 1. An automatic ?rearm with a semirigid bolt consisting of a carrier 1 in parallel relation to the catch lever 9. The pin 18 is 35 bolt head carrier provided with a camming piece and a bolt loaded by a helical compression spring 19 which is located in head which is so disposed as to be movable, within certain the bore 20 accommodating the pin 18 and acts upon the rear limits, with respect to said camming piece in the longitudinal end face of said pin 18. ' direction of the bolt and which, at two diametrically opposed Furthermore, the bolt head carrier 1 and the bolt head 2 are points, is provided with recessed; locking members being ac penetrated, in a known manner, by a ?ring pin 21. In addition, 40 commodated in said recesses, which locking members can be the bolt head is provided with a triangular recess 22 adjacent forced outward by the camming piece to a point where they to the rear end face 14, the shape of said recess matching that can leave the recesses of the bolt head in an outward direction of the sawtooth-shaped nose 12 of the catch lever 9. and enter into corresponding recesses in a barrel extension of As is apparent from FIGS. 4 and 5, the underside of the the ?rearm, characterized in that a catch lever extending in 45 catch lever 9 is provided with s semicircular cam 23 adjacent the longitudinal direction of the bolt is pivotably supported in to the nose 12. When the bolt moves into the locking position, one of two component parts of the bolt consisting of a bolt this cam cooperates with a ramp 24 disposed on one side of head and bolt head carrier, a nose of said catch lever engaging the barrel extension 25 located, in a known manner, at the the rear end of a shoulder on the other component part of the rear end of the barrel of the firearm. The ramp 24 serves as a 50 bolt with the bolt in the unlocked position, thus‘ keeping the control cam for the catch lever 9 and is so designed that under two component parts of the bolt apart, and a control cam is the action of the cam 23 it will pivot the catch lever 9 to a provided which is permanently connected to a slide and disen point where the front ?ank 13 of the nose 12 slides off the rear gages said catch lever from said shoulder when the bolt moves end face 14 of the bolt head 2. Adjacent to the ramp 24, the into the locking position. barrel extension 25 is provided with an indentation 26, into 55 2. A ?rearm according to claim 1, characterized in that said which the cam 23 can drop. control cam which is permanently connected to the slide is As will be noted from FIGS. 1 and 3, the catch lever 9, with provided with an indentation engaged by a projection of said the front end face 13 of the nose 12, keeps the bolt head 2 at catch lever when the bolt is in the locked position. such a distance from the bolt head carrier 1 that the locking 3. A ?rearm according to claim 1, characterized in that one rollers 6 in the recesses 5 of the bolt head have no contact with 60 end of said catch lever is provided with a projection which is the control surfaces 7 at the front end of the camming piece 4. engaged by a recess of the other component part of the bolt Consequently, the locking rollers 6 are completely relieved and which bottoms against one end of said recess when the from all loads during the movement of the bolt and are not bolt is in the unlocked position. forced out of the recesses 5 in an outward direction. Simul 4. A ?reann according to claim 1, characterized in that said taneously, the projection 10 at the front end of the catch lever 65 catch lever is loaded by a spring which tends to keep said nose 9 prevents the bolt head 2 from sliding off the camming piece and a projection provided on said catch lever in engagement 4 of the bolt head carrier. The bolt thus moves within the with said other component part of the bolt. ?rearm as an essentially rigid unit without exerting any forces 5. A ?rearm according to claim 1, characterized in that said on the slide 3 or other parts of the firearm. catch lever is supported in said bolt head carrier. When the bolt moves forward into the locking position, the 70 6. A ?rearm according to claim 5, characterized in that said cam 23 on the catch lever 9 is brought into contact with the catch lever, near its forward end, is provided with a sawtooth ramp 24 of the barrel extension 25 by the counterrecoil of the shaped nose, the steep ?ank of which engages the rear end face of said bolt head with the bolt in the unlocked position bolt and then raised as the bolt advances. As a result, the catch and drops into a corresponding recess of said bolt head when lever 9 will be pivoted to a point where the nose 12 slides off the rear end face 14 of the bolt head 2 and the bolt head carri 75 the bolt is locked. 5 3,566,745 a 7. A ?rearm according to claim 5, characterized in that said catch lever, near its forward end and laterally of said nose, is ponent parts so that it can move in the longitudinal direction of the bolt. 9. A ?rearm according to claim 8, characterized in that said provided with a cam extending in the same direction, said cam cooperating with a ramp disposed in the barrel extension of pin is supported in the bolt head carrier. the ?rearm, said ramp being followed by an indentation into 5 10. A ?rearm according to claim 1, characterized in that which said cam drops in the locking position of the bolt. said bolt head carrier is secured in the slide of a pistol. 8. A ?rearm according to claim 1, characterized in that a 11. A ?rearm according to claim 1, wherein said locking spring-loaded pin, which tends to push the two component members are in the form of locking rollers‘. parts of the bolt apart, is supported in one of the two com 1O 15 20 25 30 35 45 50 55 60 65 70