No. 675,999. Patented June 1, 1901.

L. HELLFRITZSCH.
AUTOMATIC SMAL ARM.
(Application filed Oct. 30, 1899.
No Model.) 2. Sheets -- Sheet

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 AUTOMATIC SMAL ARM.
(Application filed Oct. 30, 1899.)
2 Sheets-Sheet 2.

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 LOUIS IIIELLEFRITZSCIH, OF BERLIN, GERMANY.
AUTO MATIC S MALL-ARM .

SPECIFICATION forming part of Letters Patent No. 675,999, dated June 11, 1901.
Application filed October 30, 1899, Serial No. 735,269, (No model.)
To all, whom, it 7 (ty concern: end, which engages with the enlarged part d
Be it known that I, LOUIS IIELLFRITZSCH, of the barrel-casing b. The barrel c is ar
gunsmith, a subject of the King of Prussia, ranged in the casing band has a tubular end 55
Emperor of Germany, residing at Tempelko- portion d' screwed on it, which is slidable in
fer-Ufer 10, Berlin, Kingdom of Prussia, Ger- the part (d. The casing a has a longitudinal
man Empire, have invented certain new and slot g, provided with an offset portion g' on
useful Improvements in Automatic Small- one side, and the part d of the barrel has a
Arms; and I do hereby declare the following lug f, which slides in the slot g and engages
to be a full, clear, and exact description of the with its offset portion when the barrel is par
? ? invention, such as will enable others skilled tially revolved. A springh encircles the bar
in the art to which it appertains to make and rel and presses it rearwardly, thereby pre
use the same. venting it from sliding forward in its casing
The object of this invention is to construct prematurely when disconnected from the 65
an automatic small-arm in which the barrel, breech-bolt. The breech-bolt it is provided
15 as well as the breech-bolt, is mounted so as to with oblique locking-nipplese, which engage
move axially in a straight guide and also to with similar recesses in the end portion of
turn on its own axis in such a manner that the barrel. The firing-pin l is arranged in
upon being fired the barrel at first moves side the breech-bolt and is surrounded by the
backward a short distance in a straight guide, closing-spring m, which forces the breech-bolt
2O while the breech-bolt turns and with its ob- forward in the casing al. The spring n is
lique locking-nipples partially emerges from stronger than the spring h. An abutment
the corresponding obliquely-placed locking- ring i is provided for the spring in to bear
groove of the barrel - casing, then secured against. This ring has a plate i, which is 75
against further turning slides farther in a secured to the casing a. The breech-bolt c.
25 straight guide, while at the same time the has a longitudinal slot k", the rear end por
barrel emerges from its straight guide and is tion lic of which is oblique. The slot l'en
turned by the nipples, which now completely gages with the narrow guide portion of the
unlockit, while the backward movement pro- stem i, which connects the ring i with the
ceeds in a straight line, and for the purpose plate . An oblique slot k is formed in the
3o of being locked in the open position is swung upper part of the casing a, and this slotter
with a catch into a side recess. In this man- minates in a longitudinal opening or orifice
ner the locking-nipples act as the means for le. A pin lic projects from the breech-bolt
the locking of the barrel, so that the special and engages with the said slot.
constructional parts otherwise employed for The remaining parts of the firearm are of
35 this purpose are dispensed with. approved construction. The hammer q has
In Figures 1 to S of the accompanying draw- an operating-spring q'. The trigger S has a
ings a pistol is illustrated as an example of spring-operated catch l, which engages with
this kind of self-loading small-arm. Fig. 1 is the sear r, which is controlled by the spring
a longitudinal section of the new pistol in the r". A spring s' is provided for controlling
4o position ready for firing. Fig. 2 is a plan of the trigger. A magazine : for the cartridges
part of Fig. 1 after removal of the sights. is provided and a cartridge - ejector all, and
Fig. 3 is a longitudinal view, partly in sec- these parts are arranged as shown.
tion, of a pistol which has just been dis- Fig. 1 shows the parts in the firing posi 95
charged, the barrel and breech-bolt being in tion. When the cartridge is exploded, it
45 the backward position. Fig. 4 is a rear view drives the barrel and the breech-bolt rear
of the barrel-casing; Fig. 5, a cross-section of Wardly against the pressure of the spring n.
the front part of the breech-casing seen from During the first part of the recoil the breech
behind. Figs. 6 and 7 illustrate the method bolt is partially revolved by the slot k, and ?. ? ?
of locking the barrel. Figs. 8, 9, and 10 show the barrel is prevented from revolving by the
5o the arrangement for guiding the breech-bolt. slot g until its lug f comes opposite the recess
The stationary breech-casing (, is provided g'. About this time the pink passes out of the
with a screw-threaded portion at its front opening ke“, and the breech-bolt is prevented
 2 675,999
from revolving by the slotle'. The oblique nip alongitudinally-slidable breech-bolt provided
ples e now partially revolve the barrel as they with oblique locking-nipples which engage
are disengaged from it by the continued rear with the barrel; of means for partially re 45
ward motion of the breech-bolt, and the lug volving the breech-bolt independent of the
5f enters the recess g', so that the barrel is barrel during the first part of the recoil, and
locked in its rearward position. The springh means for arresting the rearward motion of
presses the barrel-lug against the end of the the barrel and permitting it to be partially
recess, so that the barrel is prevented by fric revolved by the said locking-nipples as the So
tion from revolving backward prematurely. breech-bolt becomes disengaged from it dur
O A new cartridge is forced upward in front of ing the subsequent part of the recoil, substan
the breech-bolt as soon as the latter has been tially as set forth.
driven back far enough. The forward mo 3. In a firearm, the combination, with a
tion of the breech-bolt is effected by the casing provided with a slot having an offset 55
spring an and is the converse of its rearward portion, a longitudinally-slidable barrel hav
motion. The breech-bolt is forced forward ing a lug which slides in the said slot and en
without being revolved until its oblique nip gages with the said offset portion when the
ples have engaged with the barrel and have barrel is partially revolved, and a longitudi
revolved it forcibly, so that the lug fis out nally-slidable breech-bolt provided with ob ??
of the recess g’. The pin k then enters the lique locking-nipples which engage with the
20 oblique slot k*, so that the breech-bolt is par barrel; of means for partially revolving the
tially revolved to effect the locking of the breech-bolt independent of the barrel during
nipples e with the barrel while the barrel is the first part of the recoil, thereby unlocking
prevented from revolving and while both the said nipples from the barrel and permit
barrel and breech-bolt are moving forward ting them to partially revolve the barrel as
25 longitudinally. they become disengaged from it during the
What I claim is subsequent part of the recoil, substantially
1. In a firearm, the combination, with a as set forth.
casing provided with a slot 9 having an off 4. In a firearm, the combination, with a
set portion, and having also an oblique slotki, casing provided with a slot having an offset
of a slidable and revoluble barrel provided portion, and a slidable and revoluble barrel
with a locking-lug for engaging with the off provided with a lug which engages with the
set portion of the slot 9, a slidable and rev said slot and its offset portion, and a spring
oluble breech-bolt having a pin for engaging which presses the said barrel rearwardly and 75
with the said oblique slot, said barrel and prevents its lug from leaving the said offset
35 breech-bolt being also connected by oblique portion of the slot prematurely, substantially
locking-nipples at their adjacent ends; and as set forth.
means for preventing the said breech-bolt In testimony whereof I affix my signature
from revolving on its axis after its said pin in presence of two witnesses.
emerges from the said oblique slot in the LOUIS HEILLEFRITZSCII.
4C) casing, substantially as set forth. WWitnesses:
2. In a firearm, the combination, with a W OLDEMAR LIAUPT,
casing, a longitudinally-slidable barrel, and WILLIAM MAYNER.