US2956392A - Break detection apparatus - Google Patents

Description

Cd. 18, 1960 HIROMU OHNlSHl BREAK DETECTION APPARATUS 2 Sheds-Sheet 1 Filed March 4, 1958 HIROMU OHNlSHl BREAK DETECTION APPARATUS Oct. 18, 1960 2 Sheets-Sheet 2 Filed March 4, 1958 Unite States Patent Ofiice 2,956,392 Patented Oct. 18, 1960 BREAK DETECTION APPARATUS Hiromu Ohnishi, 24 Shimizu-cho, Ashiya-shi, Hyogoken, Japan Filed Mar. 4, 1958, Ser. No. 719,115

2 Claims. (Cl. 57-81) This invention relates to automatic detection apparatus, and more particularly to the detection of sliver breakage in sliver processing apparatus.

It is an object of the invention to provide improved apparatus and methods for the detection of sliver breakage.

It is another object of the invention to provide improved apparatus and methods for detecting sliver breakage while distinguishing the same from foreign objects which are capable of causing false indications.

It is another object of the invention to provide a simplified apparatus and method to perform a sliver breakage detecting function while enabling the preservation of low costs, both as regards maintenance and production.

Still another object of the invention is to provide improved detecting apparatus which is foolproof insofar as detecting sliver breakage is concerned.

In achieving the above and other of its objectives, the invention contemplates the provision of a device which applies a suction to a sliver along the path of travel of the latter. This suction, when and if the sliver tends to break, urges the sliver in a predetermined direction along which is positioned a mechanical feeler or displ aceable element, whose position is changed due to the movement thereagainst of the sliver. In further accordance with the invention, there is is provided an electrical circuit which responds to displacement of the displaceable element for effecting a control function.

It will be appreciated that the application of suction as noted above to a sliver will tend to draw foreign objects, such as lint and insects, in the above-noted direction. Ordinarily, this would cause the displaceable element to give false indications and to control the electrical circuit at times other than when a sliver breaks. However, in further accordance with the invention, means are provided for distinguishing between the breaking of a sliver and the presence of foreign objects, said means performing its distinguishing function on the basis of the different durations of time by which the displaceable element is contacted by a sliver or by one of said foreign objects.

In accordance with one of the features of the invention other than has been indicated above, a particularly useful arrangement of displaceable elements is provided in which are provided a cam-type switch and an adjustable weight, as will hereinafter be described in greater detail.

In accordance with a further feature of the invention, special provision is made for connecting the displaceable element to the electrical circuit by means of lines which are well shielded.

As a further feature of the invention, the specific function of distinguishing between the durations of contact of different objects with the displaceable element is performed by circuitry including delay devices, such as thermistors.

Other objects and features of the invention, as well as advantages thereof, will be apparent from the following detailed description of a preferred embodiment of the invention, as illustrated in the accompanying drawing, in which:

Fig. 1 is a side view of apparatus comprising a sliver transporting device and a detector device provided in accordance with a preferred embodiment of the invention;

Fig. 2 illustrates in perspective and partially broken away a suction tube, a displaceable element (in hidden view), and a portion of the associated electrical circuit;

Fig. 3 is a front view of the apparatus of Fig. 2;

Fig. 4 is a side view of the apparatus of Fig. 3;

Fig. 5 is a top view of the apparatus of Figs. 3 and 4; and

Fig. 6 is a schematic diagram of the electrical circuit which the invention preferably employs in connection with the displaceable element in the above-indicated apparatus.

In Fig. 1 is generally indicated a sliver processing or transporting apparatus 10 comprising a frame 12 on which is supported a plurality of rollers 14. The rollers 14 form a path for movement of a sliver 16 which may, for example, be frictionally driven by rollers 14.

Directly beneath the transport apparatus 10 is generally indicated a detecting device 18 provided in accordance with the invention. The associated electrical circuit is not shown in detail in this figure.

More particularly, detecting device 18 comprises a tube 20 having a nozzle 22. To one end of the tube 18 is connected a vacuum pump 24 or some similar type of device which is capable of causing a suction in the tube 20 and, hence, at the nozzle 22.

The nozzle 22 is positioned adjacent the path of travel of the sliver 16. Hence, if the sliver 16 were to break as indicated at 26, the sliver 16 would be drawn into the nozzle 22 and hence into the tube 20.

The detecting device 18 is provided with a detection element generally indicated as element 28. As will be shown, detecting element 28 causes signals to be generated and transmitted to an electrical circuit by means of lines 30. It will be appreciated that the nozzle 22, aside from drawing in the sliver 16 when and if the same breaks, will also tend to draw into the tube 20 foreign objects, such as lint and insects. The presence of these foreign objects in the tube 2t), and more particularly in the detecting element 28, will tend to cause a malfunc tion of the device. In accordance with the invention, provision is made to avoid the deleterious effect of these foreign objects, despite their being drawn into the tube 20 via the nozzle 22.

Figs. 25 illustrate a section of the tube 20, which section supports and operates in conjunction with the detecting element 28. These figures have a similar content, excepting for the fact that a cover 34 (see Figs. 3 and 4) attached to the detecting element 28 by means of a screw or bolt 36 is removed in Fig. 2.

In Figs. 25, the detecting element 28 is illustrated as provided with a housing 38. Housing 38 is soldered, welded or otherwise connected with the tube 20 and is operatively associated with the tube 20 adjacent a region of the latter comprising a constriction 40 (Fig. 5). In this constricted portion is positioned a lever, feeler or finger 42. Lever 42 is preferably positioned perpendicularly to the axis of tube 20. Moreover, it is supported on a shaft 44 upon which the lever 42 rotates, the shaft 44 being rotated when the lever 42 is pivoted. The lever 42 constitutes the displaceable element in this embodiment of the invention.

To one end of shaft 44 is affixed a weight 46 which is eccentrically disposed with respect to said shaft. Accordingly, the weight 46 tends to move in a predetermined direction under the influence of gravity and thus establish a normal position of repose for the lever 42.

Operatively associated with the weight 46 is an adjustment screw 48. This adjustment screw is urged into abutting relationship with the housing or frame 38 so that the normal position of repose of lever 42 can be adjusted.

Fixed to the housing 38 but electrically insulated therefrom is a switch constituted in part by contacts t) and 52. Contact 50 is a fixed contact, whereas contact 52 comprises a cantilever or leaf spring portion adapted to be displaced against the contact 50. This displacement is controlled by means of a cam 54 which is affixed to the shaft 44 and rotates therewith. It follows as a consequence of the above-indicated structure that the switch constituted by contacts 58 and 52 is responsive to the movements of the lever or displaceable element 42. From this it is clear that a movement of sliver 16 (Fig. 1) through tube 2t? and against lever 42 in the direction ofarrow 56 in Fig. 2 causes a displacement of lever 42 which, in turn, causes the contact 52 to be moved against the contact 50.

The consequence of closing the switch comprising contacts 5t and 52 is next seen with reference to Fig. 6, wherein these contacts are illustrated as incorporated in a circuit adapted for performing a control function. This circuit can be employed, for example, for controlling a utility device 56 which, for example, may be a motor or an alarm.

The utility device 56 is provided with terminals 58 and 68, to which are connected switches 6-2 and 64. Actually, switches 62 and 64 are parts of electromagnetic relays, as will be indicated hereinafter. it is important to note that switches 62 and 64 are arranged in parallel and are connected via terminal 66 to terminal 66, so that if either of switches 62 or 64 is closed the circuit of utility device 556 is closed and the latter is rendered operative. Similarly, it is important to note that only when both of the switches 62 and 64 are opened is the circuit of utility device 56 opened, so that the latter is rendered inoperative.

It will be appreciated that the function hereinabove ascribed to the circuit of utility device 56 may be varied considerably within the scope of the invention. However, generally the changing of the condition of the circuit from open to closed state or vice versa will be considered to the the function of generating a control signal or performing a control operation.

To render the control circuit of Fig. 6 operative, there is provided a power source (not shown) connected across terminals 68 and '76. Across these terminals is connected the primary 72 of a transformer 74 having two secondary windings 76 and 78. These secondary windings respectively constitute power sources for their associated branches of the overall electrical circuit.

Connected in series with secondary winding 66 is the winding 80 of a relay which controls the opening and closing of switch 62. Additionally, winding 80 controls the opening and closing of a switch 82 which may be an integral part of the relay. Normally, switch 62 is closed and switch 82 is open. However, current flow through the winding 86 due to a closing of contacts 58 and 52 causes switch 82 to be closed and switch 62 to be opened.

As noted above, the opening of switch 62 does not open the circuit between terminals 58 and 60. This is due to the closed condition of switch 64. The closing of switch 32, however, permits current to flow through a relay winding 84, which has the effect of closing a normally open switch 86 which constitutes, with winding 84, a holding relay the circuit of which is closed through a switch 88 independently of switch 82 after the latter has initially enabled current to flow through winding 84. Current flow through winding 84 also operates to close a switch 9% which may be an integral part of the relay constituted by switch 86 and winding 84.

Switch 88 is an integral part of a relay comprising winding 92. Switch 64 may be an integral part of a relay comprising winding 94. Windings 92 and 94 are respectively connected in series with delay devices 96 and 98, these devices being constituted by thermistors or other similar mechanisms capable of permitting operation after a predetermined or determinable time delay. Current flow through windings 92 and 94 and, therefore, through delay devices 96 and 98 is initiated upon a closing of switch 90, which occurs virtually simultaneously with the initiation of current flow through the winding 80.

Delay devices 96 and 98 have different operational delay periods. The delay device 96 has the longer of the time delay period, which may be, for example, about ten seconds. Delay device 98, which has the shorter of the two delay period, may have a delay period of, for example, two seconds.

It is the function of delay device 98 to delay the effectiveness of winding 94, such that switch 64 is not opened until the expiration of the period of delay provided by device 98. This is very significant in that, although current flow through winding will cause an immediate opening of switch 62, switch 64 will not be opened until a predetermined period of time has elapsed following the initiation of current fiow through winding 80, this period being controlled by the characteristic of delay device 98. Accordingly, foreign objects, such as lint and flies, which tend only to cause an instantaneous displacement of lever 42 (see, for example, Fig. 2), the displacement being of short duration, can only cause switch 62 to be opened, whereas switch 64 remains closed. In other words, lever 42 must be displaced to close the switch comprising contacts 50 and 52 for a period of time which exceeds the characteristic time delay of device 98. This period of time is chosen to be a period of time which distinguishes between displacement of lever 42 by a broken sliver (i.e., a continuous displacement) and displacement of the lever 42 by foreign objects such as lint and insects.

The restoring of the electrical circuit to a condition whereat it is prepared to effect a detecting operation is provided by means of the switch 88 operating in conjunction with winding 92 and delay device 96. Following a delay period determined by the characteristic of device 96, winding 92 is effective to open switch 88. The opening of switch 88, assuming that switch 82 has been previously opened, operates to terminate current flow through winding 84. This, in turn, opens switches 86 and and, therefore, the circuit is primed for a further detecting operation which can only be effected by current flow through winding 80 and by the resulting closing of switch 82.

From the above, it is seen that switch 62 is opened immediately upon current flow through winding 89, whereas switch 64 is opened only at the expiration of a predetermined delay following current flow through winding 80, the delay being provided by delay device 98. Since both of these switches must be opened at the same time to open the circuit of utility device 56, this opening will not be caused by instantaneous displacements of lever 42, which displacements are of short duration and, consequently, the apparatus is capable of distinguishing between displacements caused by foreign objects such as have been enumerated above and by broken slivers.

Referring again to Fig. 2, it will be seen that lines 30 which connect contacts 50 and 52 to the electrical circuit of Fig. 6 are physically accommodated within a semicircular shield or casing 100 which is aflixed to the tube 20. This provides for safe, shielded connections as are provided in accordance with a further feature of the invention.

The apparatus of the invention is simple yet efficient, and permits a foolproof detection of the breaking of one or more slivers in a sliver processing device.

There will now be obvious to those skilled in the art many modifications and variations of the apparatus set 5 forth. These modifications and variations will not, however, depart from the scope of the invention if they fall within the scope of the following claims.

What is claimed is:

1. Apparatus for detecting sliver breakage comprising tube having an opening adjacent said sliver, means coupled to said tube for producing a vacuum in said tube thereby tending to suck the sliver into the tube, said sliver entering the tube only when broken, the vacuum in said tube tending to draw foreign objects into the same, a displaceable element in said tube and displaceable for short periods of time by said foreign objects and for longer periods of time by said sliver, processing means adapted for processing said sliver, control means for rendering said processing means effective and ineffective, first and second switches each connected to said control means and each of which must be opened to cause said control means to render said processing means ineffective, said first switch being controlled by said displaceable element, and means including a delay device for opening said second switch a predetermined period of time following the operation of the first said switch by said displaceable element.

2. Control apparatus responsive to a detector and capable of distinguishing between detector indications of different duration, said control apparatus comprising a circuit including two switches in parallel, said circuit being opened and therefore adapted to eflFect a control function only when both of said switches are open, a first electromagnetic means responsive to a detector indication of any duration for opening one of said switches, and second electromagnetic means responsive to a detector indication having a minimum predetermined duration for opening the second of said switches, each of said electromagnetic means being responsive to the same detector indications so that both of said switches are opened only when a detector indication exceeds in duration a predetermined minimum.

References Cited in the file of this patent UNITED STATES PATENTS 2,271,178 Blom Jan. 27, 1942 2,383,838 Auble Aug. 28, 1945 2,500,343 Carrette Mar. 14, 1950 2,704,430 Harris Mar. 22, 1955 2,812,632 Tillett Nov. 12, 1957 2,863,276 Bruening Dec. 9, 1958

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