Title:
Telltale device
United States Patent 2442275


Abstract:
This invention relates to telltale, devices-adapted to be employed in closed or open containers or bins which are designed to receive mobile material of-granular, pulverulent, flocculent, or similar nature. In systems for storing and conveying: dry granular or pulverulent material there are...



Inventors:
Augustine, Mayer
Application Number:
US246248A
Publication Date:
05/25/1948
Filing Date:
01/15/1948
Assignee:
Morse, Boulger Destructor Compa
Primary Class:
Other Classes:
200/220, 340/617
International Classes:
G01F23/00
View Patent Images:



Other References:
None
Description:

This invention relates to telltale, devices-adapted to be employed in closed or open containers or bins which are designed to receive mobile material of-granular, pulverulent, flocculent, or similar nature.

In systems for storing and conveying: dry granular or pulverulent material there are usually employed containers or bins into which the material is first charged after which the material is removed. For example, in pneumatic systems for conveying material such as dry cement or other mobile pulverulent or granular-material, the material is charged from a suitable source into a receptacle or container, and when the receptacle is filled the receptacle is arranged so that the charge may be removed from the receptacle and conveyed through conduits to another place by means of compressed air, the material-being carried through the conduit with the moving stream of air. Frequently such systems are "closed" systems and it is important to know when the receptacle, which receives the material to be "blown" therefrom, is filled with material. It-is impractical if not impossible to see inside the receptacle to observe when the material being charged into it has reached a predetermined level and, furthermore, even if the receptacle were such that the rise in level of the material could be seen, it would require personal attention for observation and this takes time which might otherwise be taken up in more usefulwork.

It is an object of this:invention to provide a telltale device which will eliminate the abovementioned drawback by providing a telltale device which is adapted for use in open or closed receptacles, containers or bins, and which is actuated by the mobile material being charged into such receptacle to give a visual or audible signal outside at a place near to or remote from it to indicate when the material being charged reaches a predetermined level or when a predetermined amount has been charged, or to indicate the height of material in a container.

According to the invention, there is provided a device of novel construction wherein a shell is suspended from above on a flexible hanger and in which there is mounted a plurality-of switches, preferably mercury switches, 'which -will close an electrical circuit upon tilting, the switches being connected in a circuit with a signal and arranged about a vertical axis in such manner that movement of the axis from the vertical will cause at least one of the switches to close the electrical circuit and thereby actuate the signal.

Although the novel features which are believed to be. characteristic of-the invention will be pointed out in the annexed claims, the invention itself as to its objects and advantages and the manner in which it may be-carried out may be better understood by reference to the following description taken in connection with the accompanying drawings forming a part hereof, in which Fig. .1is a view showing the manner of mounting ;the telltale device in a receptacle of the "closed" type; Fig. 2 is a larger scale cross-section view in elevation of the telltale device with parts broken away; Fig. 3 is a view on-line 3-3 of Fig, 2; and Fig. 4 is a wiring diagram of the electrical circuit.

Although the invention is adapted for use in connection with various forms of receptacles, bins or containers for receiving various kinds of mobile materials, it-is herein illustrated in association with a container 10 particularly designed for use in handling and pneumatically conveying various materials such as dry cement, one type of apparatus of this sort being disclosed in Letters Patent No. .2,255,438, granted :September 9, 1941, to Evelyn G. Robinson.

Such .apparatus, shown somewhat schematically in Fig. 1, comprises a container 10-of generally -cylindrical shape -at its upper end and having a domelike cover II. The cover is provided with a charging conduit 12 equipped with a valve 13 for opening and closing it. The bottom end of the container :0 is:so shaped that its wall 14 which is inclined thus forms :an inverted frustrum of a cone. Within the container is an arrangement whereby compressed air may be introduced through the line 15 and controlled by valve 16. 'When the material i7 -is charged into the container up to a predetermined quantity. valve (3 is closed, valve :1 in discharge line 19 is opened 4and compressed air is introduced through line 15. As described in further detail in said Robinson patent the pulverulent mate46 rialsis:carried-in the stream of movinga airthrough the discharge conduit and may be transported to another place.

In the course of operating this sort of apparatus it is desirable to know when a proper amount of material I47 has ibeen charged into the container; 00 through'the charging conduit 12.

The device :of this invention is admirably suited toithe purpose. It comprises a shell 20 =suspended on a flexible cable 32 which is secured to the top cover of the container ,10 as shown in -Fig. 4.

Within the shell 20 is mounted a plurality of mercury switches 21 connected to wiring which extends through a suitable opening in a mounting member 22 secured to the cover II. The wiring is connected in circuit with a suitable source 23 of electric current and, as shown, is provided with a lamp 24 which lights up when the circuit is closed. Of course, other types of signal or relays may be used in place of the lamp, and the telltale device can also be used with a circuit for initiating operation of automatic controls.

The shell 20 is preferably made of aluminum although other material may be used. It is of hollow dome or bell shape and terminates in a neck 25. A disc 26 having a central opening 27 closes off the neck portion 25 and also provides means for supporting the switch shelf 28, as described hereinafter. An inverted cup-shaped cap 29 is mounted on the neck portion 25 and it has a central opening 30 in its cover part 31 through which extends the flexible hollow supporting cable 32. The inverted cup is removably secured to the neck 25 by set screws 33.

The bottom opening of the bell-shaped shell 20 is covered with a circular disc 34 and is preferably mounted securely at its periphery 35 by clamping it between rolled flanges 36 and 37 formed at the periphery of the shell as shown in Fig. 2. The bottom closure disc 34 is provided with a central opening 38 which is provided with a wire screen 39 mounted on a flanged ring 40 having 'a peripheral flange by which it may be securely clamped to the disc 34 around the edge of the central opening 38. An air pervious cloth filter 41 is superimposed on the wire screen 39.

Thus the interior of the shell 20 communicates with the outside through the cloth filter 41. This permits the use of the device within closed containers where the pressure may be high and allows for equalization of the pressure inside and outside the shell and at the same time the filter prevents dust or other particles from getting inside.

The horizontally disposed switch supporting shelf 28 is mounted at its center on a hollow threaded nipple 42. The shelf is clamped between an upper nut 43 and a lower nut 44 threaded on the nipple. The nipple is supported at its upper end between two clamping nuts 45 and 46 which engage the disc 26 at the neck of the shell.

The flexible cable 32 which is used to suspend the device from above is made of spring wire 33 wound in helical fashion as shown more clearly in Fig. 2, thus to provide a substantial length of flexible hollow cable, the wall of which comprises the helically wound wire. The lower end of this flexible hollow cable 32 fits over the upstanding end portion of the threaded nipple 42 and is secured to it. The upper end of the flexible cable is secured to the mounting member 22.

Hence, when the device is hung !as shown, for example, in Fig. 1, the shell is free to be tilted off its vertical axis by reason of the flexibility of the suspending cable 32.

Mounted upon the supporting shelf 28 are a plurality of mercury switches 21 horizontally disposed and arranged circumferentially about the axis of the hollow supporting nipple 42, four such switches being shown. These switches are removably mounted in spring clips 50 which are secured to the shelf by bolts 51. The clips have upstanding prongs 52 which grip the glass mercury switches and thus provide means for easy replacement of the switches.

The switches are connected in parallel in the electrical circuit as shown in the wiring diagram Fig. 4. Lead-in wire 55a is connected to contact 56a of switch 21a and to wire 57; lead-in wire 49a is connected to contact 58a of switch 2 la and to wire 59; lead-in wire 55b is connected to contact 56b of switch 21b 'and to wire 57; lead-in wire 49b is connected to contact 58b and to wire 59; switches 21c and 2 Id are connected in similar fashion, as shown in the wiring diagram. The lead-in wires 55a, 55b, 49c and 55d are suitably connected to the wire 57 and lead-in wires 49a, 49b, 55c and 49d are connected to wire 59 above the shelf 28 and wires 57 and 59 are then passed through a suitable opening 48 through the shelf and then passed up through the hollow nipple 42 and hollow flexible cable 32. Wires 57 and 59 are then connected in the circuit with source of current 23 and lamp 24 on the outside of the container 10.

The operation of the device is as follows: When the device is hung in a container, such as disclosed in Fig. 1, the normal position of the shell is such that the cable hangs vertically and thus the axis of the rigid nipple 42 is vertical. Consequently, the switch shelf 28 assumes a horizontal position. When the shelf is in horizontal position the mercury 60 lies in the bottom of the glass casing of the switches and does not close the electrical contacts inside and therefore the electrical circuit remains open. However, if the shelf 28 is tilted from the horizontal the mobile mercury in at least one of the switches will assume a position to close the electrical contacts and will thereby close the electrical circuit. When the circuit is closed current flows through it to light the lamp 24.

It may now be 'assumed that the container is empty and is to be filled and the shell 20 is hanging vertically. In this position no current flows in the circuit. When the material being charged to the container reaches a level high enough to engage the bottom 34 of the shell, the shell will be tipped loff of its vertical axis because the advancing or rising surface of the material 17 will ass-une its angle of repose and cause the bottom of the shell to be moved off horizontal, thus causing the axis of the nipple 42 to be tilted and the shelf 28 to be moved off horizontal. The flexible cable 32 allows for this movement. Hence the electrical circuit is closed by one of the mercury switches and the lamp 24 glows to give the signal when the container is filled to the desired level at which the shell 20 is placed.

Although the device has been described in connection with a particular type of container or bin, for illustrative purposes, it will be understood that it may be used in other places where it is desirable to have automatic indication of the filling of mobile granular or pulverulent materials or where indication is desired of the height of material in a container. And it will be understood also that the closing of the circuit as described adapts itself to various types of signals or the operation of relays for the initiating and controlling of automatic controls.

The terms and expressions which have been employed herein are used as terms of description and not of limitation and there is no intention in the use of such terms and expressions of excluding any equivalent of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of invention claimed.

What is claimed is: 1. A telltale device actuatable by engagement with the surface of a pile of pulverulent material which comprises a flexible cable for suspension of the device from above, a rigid switch supporting member secured to the lower end of said cable which in normal position has a vertical axis, a plurality of mercury switches secured to said member, circumferentialy disposed about its axis and assuming a horizontal position when said axis is in vertical position, and an electrical circuit connected to said switches, said flexible I cable permitting said member to be tilted from its vertical axis thereby to cause at least one of said switches to close the circuit.

2. A telltale device actuatable by engagement with the surface of a rising pile of mobile granular material which comprises means providing a hollow shell, a switch supporting member within said shell, a flexible cable secured to said shell serving as means to hang said shelf for tiltable movement, a plurality of mercury switches within said shell secured to said supporting member, an electrical circuit connecting said switches, said switches remaining open when said shell is hanging freely on said cable and at least one of said switches closing when said shell is tilted.

3. A telltale device actuatable by engagement with the surface of a rising pile of mobile granular material which comprises means providing a hollow shell, a shelf supporting member within said shell, a horizontally disposed shelf secured to said member, a flexible cable secured to said shell serving as means to hang said shell for tiltable movement, a plurality of mercury switches within said shell secured to said shelf and lying in horizontal position when said shell is hanging freely on said cable and lying in tilted position when said shell is tilted, an electrical circuit connecting said switches, said switches remaining open when said shell is hanging freely on said cable and at least one of said switches closing the circuit when said shell is tilted.

4. A telltale device actuatable by engagement with the surface of a rising pile of mobile granular material which comprises means providing a substantially closed hollow shell, a nipple extending into said shell, means providing a vent in said shell, a flexible cable secured to said shell serving as means to hang said shell for tiltable movement, a switch supporting shelf within said shell secured to said nipple, a plurality of mercury switches within said shell secured to said shelf and circumferentially partially disposed around the vertical axis of said nipple, an electrical circuit connecting said switches, said switches remaining open when said shell is hanging freely on said cable and at least one of said switches closing the circuit when said shell is tilted.

5. A telltale device actuatable by engagement with the surface of a rising pile of mobile granular material which comprises means providing a .0 substantially closed hollow shell having a bottom wall, a hollow nipple extending into said shell, means providing a dust filter vent in said bottom wall, a hollow flexible cable secured to said shell serving as means to hang said shell for tiltable movement, a horizontally disposed shelf within said shell which tilts with tilting movement of said shell, a plurality of mercury switches within said shell secured to said shelf and circumferentially disposed around the vertical axis of said hollow nipple, wiring providing an electrical circuit connecting said switches, said switches remaining open when said shell is hanging freely on said cable and at least one of said switches closing the circuit when said shell is tilted, said wiring connecting said switches extending through said hollow nipple and hollow cable for connection to an outside signal.

6. A telltale device actuatable by engagement with the surface of a rising pile of mobile material which comprises a hollow bell-shaped casing having a neck portion at its upper end, a closure member closing the bottom end of said casing, a closure member for said neck portion, an air pervious filter in said casing providing means for communication between the interior of said casing and the outside, a vertically disposed hollow nipple secured at its upper end to said neck closure member and extending into said casing, a horizontally disposed switch supporting shelf secured to the lower end of said nipple, a plurality of mercury switches mounted on said shelf and circumferentially disposed around the vertical axis of said nipple, a hollow flexible cable secured at its lower end to said nipple and extending upwardly from said casing and providing means for hanging said casing for tiltable movement, and wiring connecting said mercury switches, said wiring extending through said nipple and cable to the outside of said casing for connection with a source of electrical current.

AUGUSTINE MAYER.

Certificate of Correction Patent No. 2,442,275. May 25, 1948.

AUGUSTINE MAYER It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Column 6, line 1, claim 4, strike out the word "partially"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 7th day of September, A. D. 1948. [MEAL] THOMAS F. MURPHY, Assistant Commissioner of Patents.