US3795173A

US3795173A - Cascade throttle

Info

Publication number: US3795173A
Application number: US00316377A
Authority: US
Inventors: P Freymond
Original assignee: Werkzeugmaschinenfabrik Oerlikon Buhrle AG
Current assignee: Rheinmetall Air Defence AG
Priority date: 1972-01-07
Filing date: 1972-12-18
Publication date: 1974-03-05
Anticipated expiration: 1991-03-05
Also published as: JPS4878800A; SE396996B; FR2167736A1; DE2261246A1; GB1369972A; JPS5147999B2; IT973213B; CH546891A; FR2167736B1; DE2261246B2

Abstract

A cascade throttle having a sleeve within which there are provided a number of hollow compartments or spaces bounded by partition or intermediate walls. Recesses are arranged at the intermediate walls and these recesses establish flow connections between neighboring hollow compartments. The recesses of neighboring intermediate walls and which are arranged between the sleeve member and the intermediate walls are situated diametrically opposite one another. The recesses at the intermediate wall form between the latter and the wall of the sleeve member a respective gap having the shape of a circular ring sector. Each hollow compartment is subdivided into a number of sectors by a substantially star-shaped web, and the sectors are connected with one another by throttle locations formed by the tips of the star-shaped web.

Description

Mar. 5, 1974 United States Patent [191 Freymond CASCADE THROTTLE [75] Inventor: Pierre Freymond, Wallisellen, Switzerland [73] Assignee: Werkzeugmaschinenfabrik Oerlikon-Buhrle AG, Zurich, Switzerland [22] Filed: Dec. 18, 1972 Appl. No.: 316,377

5 I8 I7 I0 Primary Examiner-Stephen C. Bentley Attorney, Agent, or FirmWemer W. Kleeman [5 7 ABSTRACT A cascade throttle having a sleeve within which there are provided a number of hollow compartments or spaces bounded by partition or intermediate walls. Recesses are arranged at the intermediate walls and these recesses establish flow connections between neighboring hollow compartments. The recesses of neighboring intermediate walls and which are arranged between the sleeve member and the intermediate walls are situated diametrically opposite one another. The recesses at the intermediate wall form between the latter and the wall of the sleeve member a respective gap having the shape of a circular ring sector. Each hollow compartment is subdivided into a number of sectors by a substantially star-shaped web, and the sectors are connected with one another by throttle locations formed by the tips of the star-shaped web.

4 Claims, 5 Drawing Figures 6 I2 3 7 II PATENTED MR 5 I974 Fi. i

5 I8 17 /0 Fig.2

CASCADE THROTTLE BACKGROUND OF THE INVENTION The present invention relates to a new and improved construction of cascade throttle possessing within a sleeve member a number of hollow compartments or spaces bounded by partition or intermediate walls, recesses being arranged at the intermediate walls and such recesses establishing flow connections between neighboring hollow compartments, the recesses of the I neighboring intermediate walls and which are arranged between the sleeve member and the intermediate walls are located diametrically opposite one another.

A known construction of cascade throttle has the axial extent of the intermediate walls approximately equal to the axial extent of the hollow compartments, and the recesses at the intermediate walls possess the shape of circular segments.

In order to attain optimum throttling action with a cascade throttle the throttle locations in the flow direction should be as short as possible, i.e., the intermediate walls should be thin. On the other hand, for reasons of strength cylindrical intermediate walls should not be too thin, otherwise they will become deformed by the gas pressure. Furthermore, for each throttle action the cross-section of a throttle opening should possess a large peripheral length in relationship to the throughflow surface, and the throughflow surface therefore should have the form of a narrow gap.

The known cascade throttles do not fulfill these two requirements concerning narrow intermediate walls and narrow gaps.

SUMMARY OF THE INVENTION Hence, it is a primary object of the present invention to provide a new and improved construction of cascade throttle which effectively and reliably overcomes the aforementioned drawbacks and limitations of the prior art constructions.

It is another object of the present invention to provide an improved construction of cascade throttle by means of which there can be realized optimum throttlirig action with short main throttle locations, and wherein by reinforcing the intermediate walls externally of the region of the throttle locations there can be avoided deformation of the intermediate walls and at the same time there can be provided additional throttling locations.

Now in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the cascade throttle of this development is manifested by the features that each of the recesses at the partition or intermediate walls between the latter and the wall of the sleeve member form a gap possessing the shape of a substantially circular ring sector, and each hollow compartment is subdivided into a number of sectors by a substantially star-shaped web member, and the aforementioned sectors are connected by throttle locations formed by the tips of the star-shaped web member.

The cascade throttle of this development can be advantageously arranged in a cadence control or regulator for an automatic firing weapon.

With a known cascade throttle of this type for the cadence control of a firing weapon it has been found that with increasing heating-up of the firing weapon the hotter gases, owing to their increased pressure, are throttled less intensively, so that the cadence increases.

The present invention aims at maintaining the cadence constant independent of the temperature of the gases while avoiding a too large size cascade throttle with a great number of cutouts.

With increasing temperature of the gasses, i.e., with increasing gas pressure, the throttling action of the individual cutout becomes greater, so that with a predetermined number of cutouts the cadence remains constant. With the conventional construction of throttle the required number of cutouts for attaining a constant cadence is however so large that the entire unit becomes much too large in size. The construction of throttle of this development renders possible reduction of the required number of cutouts for attaining a constant cadence.

BRIEF DESCRIPTION OF THE DRAWING The invention will be better understood and objects other than those set forth above, will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawing wherein:

FIG. 1 is a sectional view through the barrel of a firing weapon at the region of the gas removal channel and through a gas cylinder arranged therebelow with an insert member;

FIG. 2 is an enlarged view of the insert member arranged in a sleeve and employed in the arrangement of FIG. 1;

FIG. 3 is a cross-sectional view of the insert member arranged in a sleeve as depicted in FIG. 2, and taken substantially along the line IIIIII thereof;

FIG. 4 is a cross-sectional view of the arrangement depicted in FIG. 2, taken substantially along the line IV-IV thereof; and

FIG. 5 is a cross-sectional view of the arrangement depicted in FIG. 2, taken substantially along the line VV thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Considering now the drawing, according to the showing of FIG. 1 a barrel or tubular member 1 is inserted in a closure housing 2 of an automatic firing weapon. The closure housing 2 possesses a cylindrical compartment 3 connected by a gas removal or withdrawal channel 4 with the interior of barrel 1. The cylindrical compartment 3 is closed by an insert member 5 and contains a displaceable piston 6 to which is secured a piston rod 7.

The rear end 7a of the piston rod 7 extends through an end wall 20 bounding the cylindrical compartment 3 and bears against a sleeve member 8 subjected to the pressure of a spring 9 or equivalent structure. According to the showing of FIG. 1, the piston 8 bears with its end surface 8a against the rear end surface 10 of insert member 5. In the cylindrical compartment 3 there is arranged a package of annular or ring springs 11 functioning as a buffer for the piston member 6, and which cooperate with a ring-shaped or annular stop or shoulder 12 of the piston rod 7. A bore I3 opens into the cylindrical compartment 3 and communicates the interior thereof with the surrounding atmosphere.

As best seen by referring to FIG. 2, the insert member 5 possesses threading 14, a threaded head 15 with an internal hexagonal bore 16, so that the insert member 5 can be sealingly threadably screwed into the closure housing 2..

Further, the insert member 5 possesses a central blindhole bore 37 which opens into the end surface H and widens forwardly thereof. According to the showing of HGV 3, it will be recognized that four bores 38 open into the end of the blindhole bore l7 and are located essentially perpendicular thereto. Between the threading l4 and the one flange 20 of the insert member there are provided a row or series of cutouts 46 which are formed by the partition or intermediate walls 2i. These partition walls Zll, as best seen by referring to FIG. 4, possess along one half of their periphery a larger diameter than over the remainder of their periphery.

The web 21a between two neighboring partition or intermediate walsl 211 possesses four arch-shaped recesses 22, so that there are formed four substantially radially extendings arms Zlb possessing the

tip portions

23 and 24 of the star-like web. As particularly well recognized by inspecting FIG. 4 both of the tip portions 23 are somewhat longer than both of the tip portions 24.

As clearly seen by referring to FIG. 5, only the web between the flange and the first partition wall 21 is constructed in such a manner that its tips 27 all possess the same length. In order to ensure that the partition walls are as stiff as possible there is provided the largest possible radius 28 at the transition location between the web and partition wall according to the showing of FIG. 4. The rigidity of the partition walls is especially also increased by the

aforementioned tip portions

23, 24 and 27. The tips 24 have the additional function of acting as throttle locations. The flange 20 possesses a groove 29 in which there is located a sealing ring member which prevents gas from flowing out of the cutout directly behind the flange into the space in front of the piston 6.

As best seen by referring to FIG. 1, the gas flows firstly through the gas removal channel 4 into the cutout 40 behind the flange Ed. in this first cutout the gas initially must flow past the tips or tip portions 27 and moves out of such cutout past the first partition wall Zll into the neighboring cutout. However, the gas can only flow past one half of the periphery of the first partition wall 21 which possesses the smaller diameter, since the other half containing the larger diameter sealingly bears against the sleeve member 36D, as shown.

At the second partition wall 21 the portion with the smaller diameter is offset by 180 with regard to the portion of the first partition wall. Therefore, if the gas is to arrive from the second into the third cutout, it must first flow past the tips 24 of the web between the partition walls 21, so that it can flow past the second partition wall into the third cutout.

In this manner the gas at each cutout must initially flow past both of the tip portions 24 before it can flow past the next partition wall 21 into the next successive cutout. Consequently, the gas is throttled on the one hand by the ring gap which extends over one-half of the periphery or circumference and located between partition wall and sleeve member 30 and, on the other hand, is also throttled during the time that it flows past the tip portions 24.

Qonsequently, the gas is throttled at each cutout at two locations. so that there is realized a pronounced pressure drop. The final pressure is independent of the starting pressure so that there is produced a constant cadence.

As soon as the gas has flown past all of the partition walls 21 it arrives at the last cutout into which open the four bores iii. The gas flows through these bores 18 into the blindhole bore l7 and flows through such bore 17 towards the end surface 8a of the piston 6, whereby such is pushed against the package of ring springs lll.

While there is shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto. but may be otherwise variously embodied and practiced within the scope of the following claims.

Accordingly, what is claimed is:

l. A. cascade throttle arrangement comprising a sleeve member containing a number of hollow compartments bounded by partition walls, said partition walls being provided with recesses establishing connections between neighboring hollow compartments, the recesses of neighboring partition walls which are arranged between the sleeve member and the intermediate wall being located at diametrically opposed locations, the recesses at each partition wall forming between the latter and the wall of the sleeve member a gap possessing the shape of a substantially circular ring sector, each hollow compartment being subdivided by a substantially star-shaped web member into a number of sectors, said sectors being connected by throttle locations formed by tip portions of the star-like web member.

2. The cascade throttle as defined in claim l, wherein said sleeve member is exchangeable, an insert member possessing said partition walls being arranged in said exchangeable sleeve member, and wherein the partition walls contact in sealing fashion against the sleeve member at least over one-half of the peripheral extent thereof.

3. The cascade throttle as defined in claim 2, wherein said cascade throttle is employed in the cadence control of an automatic firing weapon.

4" A cascade throttle arrangement comprising a sleeve member equipped with partition walls bounding a number of hollow compartments, said partition walls having recesses for connecting neighboring hollow compartments, the recesses at the partition walls forming between the latter and the wall of the sleeve member respective gap means each possessing the shape of a substantially circular ring sector, each hollow compartment being subdivided by a substantially starshaped web member into a number of sectors, and said sectors being connected by throttle locations formed by tip portions of the star-like web member.

Claims

1. A cascade throttle arrangement comprising a sleeve member containing a number of hollow compartments bounded by partition walls, said partition wallS being provided with recesses establishing connections between neighboring hollow compartments, the recesses of neighboring partition walls which are arranged between the sleeve member and the intermediate wall being located at diametrically opposed locations, the recesses at each partition wall forming between the latter and the wall of the sleeve member a gap possessing the shape of a substantially circular ring sector, each hollow compartment being subdivided by a substantially star-shaped web member into a number of sectors, said sectors being connected by throttle locations formed by tip portions of the star-like web member.

2. The cascade throttle as defined in claim 1, wherein said sleeve member is exchangeable, an insert member possessing said partition walls being arranged in said exchangeable sleeve member, and wherein the partition walls contact in sealing fashion against the sleeve member at least over one-half of the peripheral extent thereof.

4. A cascade throttle arrangement comprising a sleeve member equipped with partition walls bounding a number of hollow compartments, said partition walls having recesses for connecting neighboring hollow compartments, the recesses at the partition walls forming between the latter and the wall of the sleeve member respective gap means each possessing the shape of a substantially circular ring sector, each hollow compartment being subdivided by a substantially star-shaped web member into a number of sectors, and said sectors being connected by throttle locations formed by tip portions of the star-like web member.