US2244285A - Fluid-operated alarm - Google Patents

Description

Patented June 3, 1941 FLUED-QPERATED ALARM Application @December `19, 1939., Serial No. 310,042

In Sweden December 3,0, 1938 ('Cl. rie-24) 6A Claims.

This invention relates to an. apparatus for making periodical signals by means of prefer,- ably monotonie elastic huid-operated alarms, such as sirens, in which the supply of air or gas tothe alarm is controlled by a shut-oit dey vice, such as a valve, actuated by one or more movable. members which upon displacement are adapted directly or indirectly to actuate the said shut-oli device by, dilerent` portions so as alternately. to open and close the shut-off device.

Inpreviously known control devices ofA the type indicated for. opening and closing the shut-off device, the movable member or membersarevery complicated due to the fact that they are constructed as rotary members which require special means for imparting rotational movement theretot, Besides,r in case of such rotational members it is very, diicult to provide meansv for making different periodical signals. v

The objects of my improvement are to provide aLsimplied member for opening and closing the shut-off device; to utilize a movement required in connection withthe operation of the alarm for the actuation of the said. member; toprovide ancolntrolmember which will be easily adjustable, whereby to actuate the shut-oli device in different waysso as to give diierentperiodical signals; and to provide a controlmember which. can be adjusted by any person to any of the existing signals and which, after it has been adjusted, enf sures that the proper signal will be made when the apparatus is operated.

With the above and other objects in View the present invention consists in the construction and novel` combination and arrangement of parts hereinafter fully described, illustrated in the accompanying drawing and pointed out in the clairnshereunto appended.

The invention is illustrated by way of example in -the accompanying drawing, in which:

Fig. 1 is avertical section of an air pump ccnnected to an. alarm apparatus partly shown in the drawing, the upper portion of the pump containing the control member and shut-off device, the figure being shortened in height byomitting cylindrical portions at three places;

Fig.- 2l is a horizontal section of a part of the apparatus on line 2 2, Fig. 1;

Fig. 3 is a horizontal section of a part of the apparatus online 3 3, Fig. 1;

Fig. 4is a longitudinal section of a part of the piston rod shown in Fig. 1; and

Fig.` 5, is achorizontal section of the piston rod Shown in Fig. 1.

All. of the Figs. 2 to 5 areA details ofi the novel control member according tothe invention.

Referring to theA drawing, the air pump comprisesan upper plate 6, a lower plate 8, an outer cylindrical jacket Idoi sheet metal or the like material, and a similar inner jacket I6, saidjackets being inserted between the plates 6V and 8- by means oi bolts l0 and nuts l2. The jacket i6 constitutesy the cylinder of theair pump. The surfaces of the jackets and plates facing each other should be well ground so as to secure an effectiveY seal. The plates 6 and` 8 are provided with abutments t8, 2D, 22 for maintaining the jackets. in place. A piston 24 provided with a piston rod 26. is arranged to reciprocate in the cylinder i5. rThe piston has a cover 28 secured thereto .by means of screws 3B. Piston rings 32; 34 are arrangedbe'tween the piston and the-jacket i6. The piston formsa hollow space 36, andalso the piston rod is hollow, the hollow space 38 eX- tending throughout the whole length of thepiston rod. The upper wall of the piston has an opening 40, and the cover 28 has. an opening-42, saidopeningsbeing provided with flap valves G8 ando, respectively, pivoted at 44 and 46, respectively. The pivots.. are mounted in lugs 52 and 5i, respectively, formed on the-piston. Normally, the valvesare held in closed position by means of leaf springs. 5G, 58 which are secured to the piston byv means of screws Eil and 62, respectively. At the bottom and top of thecylinder |6- there are providedvalves, the bottom-valve consisting of. arubber or leather packingv 64 which is inserted between twoplates- ES and 68 which are securedto the packing by means of three screws two. of which, mand "i2, being shown in the drawing. The said screws are threaded into supports '14, 'I6 projecting from the bottom plate 8, whereby a.V hollow space 'i8 is formed between the bottom valve and the plate 8. At theperiphery, the packing, Sli. is-bent downwards so that it tightly ts the jacket IS Vwhich has openings 80 for communication betweenthe hollow. space 'l8- andthe space between the jackets Iliand I6.

In a similar manner, the top valveconsists of a rubber` or leather packing 82 inserted between two plates 84 and 8S, which are secured to the packing by means of three screws 88 one of which only is shown in tliev drawing. Thesaid screws are threaded intosupports 90 pendent from the upper plate whereby a hollow space 92 is formedv wherel the piston rod 26; extends through theztopvalve, the packing 82 is bent downwards so as to form a tight t against the piston rod. The upper plate 6 has an opening 84 which connects the space 92 and the space between the jackets I4 and I6 with a chamber 96 located above the plate 6.

The chamber 96 serves .as an accumulator for compressed air and is enclosed by an outer jacket 58 and an inner jacket |00, said jackets being inserted between a casing |02 and the upper plate 6 by means of sleeve-like nuts |04 and |06. To this end, the jacket is internally threaded at both ends. The edges of the jackets 98 and |00 and the abutting surfaces of the casing |02 and the plate 6 are plane ground to obtain an eiective seal. Annular projections |08, |10, H2, and ||4 are provided on the casing |02 and on the plate 6, and it will be seen that the chamber 80 is entirely closed. A packing ring |05 is inserted between the pl-ate 84 and the nut |04. The piston 25 extends through the sleeve-like nuts |04 and |06 which form guides and bearings for the rod with a tight t so that leakage of air from the space 62 and between the piston rod and the nuts will be entirely or practically entirely prevented.

The chamber 56 is connected through a passage ||6 provided in the casing |02 with the siren |I8 the mouth |20 of which is partly shown in section in Fig. 1 and the air inlet connection |22 of which is connected to the outlet connection |24 of the passage H6. This passage opens to the chamber 96 by a valve seat |26 adapted to be closed by a shut-off valve |28. By means of a nut |30, the valve is secured to a Stern |32 which is longitudinally movable in a bushing |34 mounted in the wall of the passage 6. A spring |21 secured to the casing |02 by means of screws 20 normally keeps the valve in contact with the valve seat.

The casing |02 forms a chamber |38 which at the upper side is closed by a cover |40 attached to the casing by means of circumferentially arranged screws |42, one of which only being shown in the drawing. The piston rod 20 also extends through the cover |40 and is guided therein by a bushing |44 which is rotatably mounted in the cover and has threaded thereon a pointer |46. The pointer is provided on its lower side with a projection |48 which by rotation of the pointer can be brought into engagement with any of a plurality of recessses |50 provided in the cover, only one of these recesses being shown in the drawing. The piston rod is provided with a longitudinal key |45 secured thereto by screws |41, and the bushing |44 has a corresponding keyway (see Fig.

The upper portion of the piston rod has an opening |52 which is disposed so that it will always be located above the cover |40, even if the piston is in its lowermost position. As a result thereof, the space 36 of the piston will always be in open communication with the atmosphere through the opening |52 and the interior 38 of the piston rod. The uppermost portion of the piston rod is provided with a wooden handle |54 secured thereto by means of a pin |56 and a cotter |58 and reinforced by a bushing |60.

The piston rod which can be reciprocated and turned about its longitudinal axis has, in accordance with the invention, a plurality of longitudinally extending outer cam surfaces |62, |64, |66, |68, as shown invFigs. 4 and 5 rather than in the sectional view of Fig. 1. These cam surfaces are shaped in different manners and are disposed on that portion of the piston rod which always is located above the upper plate 6. Se cured to the casing |02 by means of a bolt |12 and a nut |14 is a support |10 the upper portion of which is bifurcated and has mounted therein a pivot |16 fixed by means of a cotter |18. Mounted on the pivot |16 is a lever having two arms located on opposite sides of the piston rod. On the right hand ends, as viewed in the drawing, the arms |80 are arranged to clamp the upper end of the valve stem |32 by means of bolts |82, |84. At a place below the pivot |16, links |86 and |68 are pivoted to the arms |80 as by pivots |90 and |92, respectively (see Fig. 3). A roller |94 is rotatably mounted on the links, said roller abutting against one of the cam surfaces of the piston rod. By means of abutments |96 and |98 fixed to the arms |80, the links |86 and |88 are normally held in horizontal position.

The mode of operation of the apparatus described is as follows:

If the piston by pressure on the handle |54 is moved downwards from its uppermost position, the air present in the cylinder l5 below the piston will be compressed, since the valve 50 is kept in closed position by the spring 58. At the same time, the valve 48 will be opened, since subatmospheric pressure will prevail above the piston, and air will flow through the opening |52, the interior 38 of the piston rod, and the opening 40 into the space labove the piston. When the pressure in the space below the piston has been increased to a certain value the peripheral bent-down portion of the packing 64 will be pressed inwardly so that the compressed air will flow to the space 18 and hence through the space between the jackets I4 and I6 and through the opening 94 into the chamber 96. During the downward movement of the piston rod the roller |94 will be actuated by the cam surface |62 so as to impart to the lever |80 a rocking movement about the pivot |16, with the result that the shutorf valve |28 will be alternately opened and closed so as to permit of periodical flow of air through the passage ||6 and to the siren which will make signals of a character corresponding to the shape of the cam surface |62.

When the handle |54 is pulled upwards, the valve 48 will be closed, and the air in the space above the piston will be compressed. When the air has been compressed to a certain value, it will ow past the peripheral portion of the packing 82 into the space 62 and hence through the opening 94 into the chamber 96. Since the roller |94 is mounted on the links |86, |88, it will be turned, during the upward stroke of the piston, about the pivots |90, |92 in an anti-clockwise direction out of the path of movement of the cam surface without actuating the lever |80, with the result that the shut-oil valve |28 will be kept in closed position during the upward stroke. During the downwardstroke, the links |86, |88 rest on the abutments |96, |98, and in this case, the roller |94 can be regarded as being rigidly mounted in the arms |80. While I have found that the provision of the links |86, |88 is very advantageous, it will be evident that the roller may be mounted directly in the arms |80.

The pointer |46 is slightly resilient so that the projection |48 thereof can be brought into engagement with any or the recesses |50 the number and locationl of which corresponds to the number and'` location of the cam surfaces |62, |64, |66, |68. Suitable marks on the cover |40 may be provided to indicate which of the different signals corresponds to the position of. the pointer. Since the bushing I 44 is keyed on the piston rod, it will be seen that the pointer will follow any turning movement of the piston rod, and after the pointer has thus been adjusted to a certain signal, the angular position of the parts will be maintained, during the reciprocation of the piston, due to the key connection and the cooperation of the projection |48 with the corresponding recess |50.

It will be evident from the above description that the invention provides a simple control member for effecting the opening and closing movements of the shut-olf valve, in contrast to rotary control members which require additional means for imparting rotary movement to the control member. A further advantage of the novel construction resides in the fact that the movement of the piston rod is directly utilized for actuating the air admission valve. A still further advantage consists in the possibility of providing a plurality of different cam surfaces on a single piston rod, which surfaces can be put into operative position in a simple manner by turning the piston rod about its longitudinal axis and thereby electing any desired signal. These signals can be easily adjusted by means of the pointer, and the elected position of the parts will be maintained by the cooperation of the parts as described.

While in the foregoing description I have confined my consideration to a preferred embodiment of my invention, it Will be understood that the invention is not confined to this specific arrangement but may be modified as to constructional details Within the scope of the appended claims construed as broadly as is consistent with the prior art.

lfVhat I claim is:

1. In a fluid-operated alarm, an alarm device, valve means for controlling the fiovv of. fluid to said alarm device, means for compressing the fluid, a member having a longitudinal cam surface and being arranged to be reciprocated, said means for compressing the fluid being connected with said member to reciprocate the same, and means arranged to be actuated by cooperation with said cam surface for alternately opening and closing said valve means in response to movements of saidy member so as to effect periodical ow of fluid to the alarm device for producing signals of character corresponding to the shape of the cam surface.

2. In a fluid-operated alarm, an alarm device, valve means for controlling the ovv of fluid to said alarm device, a member having a plurality of different longitudinal cam surfaces around its circumference, means for imparting a reciprocating movement to said member, valve actuating means arranged to be actuated by cooperation with any of said cam surfaces for alternately opening and closing said valve means in response to movements of said member so as to effect periodical iiow of fluid to the alarm device for producing signals of, character corresponding to the shape of the cam surface in operation, and means for turning said member, whereby to bring said valve actuating means into contact with any of said cam surfaces.

3. In a uuid-operated alarm, an alarm device, a reciprocating fluid pump including a piston and a piston rod, a conduit for supplying uid compressed in said pump to said alarm device, a valve in said conduit for controlling the flo-W of compressed uid to said alarm device, said piston rod having a longitudinal cam surface, and valve actuating means arranged to be actuated by cooperation with said cam surface for alternately opening and closing said valve in response to movements of said piston rod.

a. In a duid-operated alarm, an alarm device, valve means for .controlling the oW of fluidi to said alarm device, means for compressing the fluid, a member having a plurality of'. different longitudinal cam surfaces, said means for compressing the iiuid being connected with said member in order to reciprocate the same, valve actuating means arranged to be actuated by cooperation with any of said cam surfaces for alternately opening and closing said valve means during one stroke of said member, means for releasing said valve actuating means during the return stroke of said member, and means for turning said member, Where to bring said valve actuating means into contact with any of said different cam surfaces.

5. In a fluid-operated alarm, an alarm device, valve means for controlling the flow of fluid to said alarm device, means for compressing the fluid, a member having a plurality of diiferent longitudinal cam surfaces, said means for compressing the fluid being connected with said member in order to reciprocate the same, valve actuating means arranged to be actuated by cooperation with any of said cam surfaces for alternately opening and closing said valve means in response to movements of said member so as tol eiect periodical flow of fluid to the alarm device for producing signals of character corresponding to the shape of the cam surface in operation, means for turning said member whereby to bring said valve actuating means into contact with any of said cam surfaces, and means associated With said member for indicating that of -said cam surfaces which is in contact with said valve actuating means.

6. In a huid-operated alarm, an alarm device, a reciprocating fluid pump including a piston and a piston rod, a conduit for supplying fluid compressed in said pump to said alarm device, a valve in said conduit for controlling the oW of compressed fluid to said alarm device, said piston rod having a longitudinal cam surface, means arranged to be actuated by cooperation With said cam surface for alternately opening and closing said valve during one stroke of said piston, and means for releasing said valve actuating means during the return stroke o-f said piston.

JOHN GUsTAF MAURITZ BRODN.

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