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Publication numberUS3872964 A
Publication typeGrant
Publication dateMar 25, 1975
Filing dateMay 19, 1972
Priority dateMay 19, 1972
Publication numberUS 3872964 A, US 3872964A, US-A-3872964, US3872964 A, US3872964A
InventorsHiggins Lester A
Original AssigneeScandia Packaging Mach
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Assembly for detecting irregular feed conditions
US 3872964 A
Abstract
An assembly includes a conveyor means for moving articles along a path and a detecting circuit means for sensing an irregular feed condition for the articles moving along the path. A logic circuit receives an input signal from the detecting circuit means and transmits an output signal to a control circuit means. The control circuit means is responsive to a preselected output signal from the logic circuit to stop the conveyor means from moving articles along the path when an irregular package feed condition is detected.
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Description  (OCR text may contain errors)

tlnite States Higgins [11] 3,872,964 [451 Mar. 25, 1975 ASSEMBLY FOR DETECTING IRREGULAR FEED CONDITIONS Primary Examiner-Even C. Blunk Assistant Examiner-Douglas D. Watts Attorney, Agent, or FirmMarkva & Smith [5 7] ABSTRACT An assembly includes a conveyor means for moving articles along a path and a detecting circuit means for sensing an irregular feed condition for the articles moving along the path. A logic circuit receives an input signal from the detecting circuit means and transmits an output signal to a control circuit means. The control circuit means'is responsive to a preselected output signal from the logic circuit to stop the conveyor means from moving articles along the path when an irregular package feed condition is detected.

A feature of the invention is directed to the use of two transducer means constituting sensing means which are sensitive to the physical presence of a package being moved a spaced distance therepast. The two transducer means are laterallly displaced with respect to each other along said path by an amount effective to operate the transducers sequentially under normal feed conditions and to operate the transducers simultaneously when an irregular feed condition is present.

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= N0 PACKAGES FIG. .5

NORMAL CONDITION ONE PACKAGE OVER "/9" FIG. 5

N ORMAL CONDITION ONE PACKAGE OVER ll"- k- 20 FIG. 7

ABNORMAL CONDITION I BOTH TRANSDUCERS OPERATING FIG. 8

ASSEMBLY FOR DETECTING IRREGULAR FEED CONDITIONS BACKGROUND OF THE INVENTION There are many well known types of conveyor means which are used to move articles from a supply work station to various other operational work stations. Where the operational work stations are set up to receive at least one article or a series of articles at predetermined intervals, 21 very precise feed condition is required. This feed condition is preselected and must be maintained between the supply station and the operational work stations if the machine is to run properly. This fact is especially true where the conveyor means is running under fully automatic conditions.

There are occasions when irregular feed conditions will exist while articles are being conveyed from a supply work station to the operational work stations. If such an irregular feed condition were to be maintained until the articles reached the operational work station, damage may very well be done to the machine working on the articles. This, of course, results in a shut down of operations and costly repair work which must be done on the machine.

Examples of irregular feed conditions include several situations. If more than one package is fed in a mechanism designed to feed only one package at a time, the conveyor must be stopped. A package improperly oriented with respect to the conveyor means should be detected. Any other similar type of irregular feed condition different from the normal condition for which the conveyor means has been designed must be detected.

PURPOSE OF THE INVENTION The primary object of this invention is to provide electrical and mechanical means for detecting and preventing irregular conditions in any article handling machine.

A further object ofthis invention is to provide a sensing means responsive to irregular feed conditions in a conveying means to avoid disadvantages attendant prior art conveying devices.

A further object of this invention is to provide a combination of elements which will detect irregular package conditions in a high speed conveying mechanism and insure a quick and safe stoppage of the work flow.

SUMMARY OF THE INVENTION The combination as described herein includes a means for moving packages along a path and a sensing means located along the path to detect an irregular feed condition. The sensing means includes two transducer means such as proximity switches which are sensitive to the physical presence of a package being moved a predetermined spaced distance therepast. The two transducer means are laterally displaced with respect to each other by an amount effective to operate each of the transducer mechanisms sequentially under normal feed conditions. The transducers are to operate simultaneously when an irregular package feed condition is present.

Another feature of this invention is the use of a logic circuit in combination with a conveyor means for moving articles along a path and a detecting circuit means for sensing an irregular feed condition for articles moving along said path. The logic circuit receives an input signal from the detecting circuit means and transmits an output signal. A control circuit means is responsive to a preselected output signal from the logic circuit to stop the conveyor means from moving articles along the path when an irregular feed condition is detected.

A further feature of this invention is directed to the use of specific combinations within a wrapping machine.

BRIEF DESCRIPTION OF DRAWINGS Other objects of this invention will appear in the following description and appended claims, reference being made to the accompanying drawings forming a part of the specification wherein like reference characters designate corresponding parts in the several views.

FIG. 1 is a top plan view of an apparatus made in accordance with this invention,

FIG. 2 is a sectional view along line Il-II of FIG. I,

FIG. 3 is a schematic drawing showing the operation of the apparatus of FIG. I under normal feed conditrons,

FIG. 4 is a schematic drawing showing the apparatus of FIG. 1 when an irregular feed condition is present,

FIGS. 5, 6 and 7 are partial circuit diagrams showing electro-mechanical equivalents of the apparatus in FIG. 1 under normal feed conditions,

FIG. 8 is a partial circuit diagram showing the electro-mechanical equivalent of the apparatus of FIG. I under irregular feed conditions,

FIG. 9 is a schematic diagram ofa modification of an assembly made in accordance with this invention.

DESCRIPTION OF SPECIFIC EMBODIMENTS More specifically, a conveyor assembly, generally designated 10, incorporates an apparatus for detecting and preventing irregular feed conditions for articles moving along a path. The assembly 10 is generally well known and includes conveyor chains 11 which move along a channel or track 18. Pusher members 12 are connected at each end thereof to each of the chains 11.

Under normal feed conditions, pusher members 12 engage one side of a package 13 and moveit along a package support means 14. Normal operation of a conveyor assembly made in accordance with this invention is shown schematically in FIG. 3.

Typical irregular package feed conditions are shown in FIG. 1. Two packages 15 and 16 may be accidentally placed in front of the pusher member 12. This is commonly referred to as a double package condition. The package 17 shown in FIG. 1 is improperly oriented with respect to the pusher member 12. This is commonly referred to as a skewed package condition. The double package condition is also shown in FIGS. 2 and 4.

The conveyor assembly 10 moves the packages 13 along a path defined by the package support means 14. The sensing means of this invention is located along this path to detect an irregular feed condition as discussed hereinabove. Proximity switches 19 and 20 constitute two transducer means which are sensitive to the physical presence of a package being moved a predetermined spaced distance therepast. That is, when a magnetic material comes into close proximity of the switches 19 and 20, they each experience a change in condition to produce a particular type of output signal. Such a proximity device is well known in the prior art and is commercially available for use. There are other types of transducers that work merely on the basis of the capacitance of the package itself. That is, instead of using metal foil to activate the device, the capacitance of the package itself will change the characteristics of the unit producing a similar type of output signal. The signal is monitored or responded to by other associated devices or circuitry.

The proximity switches 19 and 20 are laterally displaced with respect to each other by an amount effective to operate one after the other or sequentially under normal feed conditions. That is, first 19 would be activated by a package 13 moving thereover and then subsequently the switch 20 would be activated by the same package as it moved along the desired path. In this specific embodiment, the switches 19 and 20 are disposed beneath the package support means 14 and are registered with openings 21 and 22, respectively. The openings 21 and 22 could be replaced by a slot configuration extending in the longitudinal direction of the path traveled by the package 13. This would enable the switches 19 and 20 to be adjusted with respect to each other so that the distance therebetween may be adapted to various sized packages being conveyed by the assembly 10.

The lateral displacement between the devices 19 and 20 is such that they will be activated or operated simultaneously when an irregular package feed condition exists in the assembly 10. Such a condition is shown in FIG. 1 wherein a skewed package 17 or a double pack condition 15 and 16 will simultaneously activate the devices 19 and 20.

Another feature of this invention is the use of an electronic control logic circuit 23 used in conjunction with the detecting circuit means or proximity switches 19 and 20 which sense the presence of an irregular article feed condition along the package support means 14. The logic circuit 23 receives an input signal from the proximity switches 19 and 20 and transmits an output signal based upon a preset or predetermined logic circuit arrangement. In this specific embodiment, the logic circuit is a NAND circuit 23. Here again, this type of logic circuit is commercially available, but heretofore has not been used in combination with such an irregular feed condition detecting circuit. Lines 27 and 28 represent the connections to the line voltage for the logic NAND circuit 23. That is, power is supplied to the logic circuit 23 through the lines 27 and 28.

The control device 24 is operated on the basis ofoutput signals from the NAND circuit 23. The control device 24 constitutes a control circuit means that is responsive to a preselected output signal from the logic circuit 23 to stop the conveyor assembly 10 from moving articles along the path when an irregular feed condition is detected. The control device 24 can be any mechanism such as a starter, relay or the like which will interrupt the operation of the assembly 10. A control relay can be used to stop the operating motor or simply turn the clutch off and apply a brake to the assembly 10.

In operation, the logic circuit 23 is present to transmit a first output signal that allows the control circuit means or control device 24 to run the assembly 10 under normal feed conditions. When an irregular package feed condition exists, the NAND circuit 23 is preset to transmit a second output signal that tells the control circuit device 24 to stop the operation of the assembly 10. This operation is explained in electromechanical relay equivalents in FIGS. 5, 6, 7 and 8.

When there are no packages being moved by the conveyor assembly 10, the capacitance switches are in a closed condition as shown in FIG. 5. As the packages 13 move in the direction A, they first pass over the switch 19 which opens while the switch 20 remains closed. At this point there is no change in the output signal with respect to the logic circuit 23. This condition is shown in FIG. 6.

The package 13 then passes over the proximity switch 20 which is opened and the switch 19 is then closed. This condition is shown in FIG. 7 and again the logic circuit 23 maintains the same output signal characteristic with respect to the control device 24. The three conditions as set forth in FIGS. 5, 6 and 7 represent normal package conditions in the operation of the assembly 10.

Reference to FIGS.'4 and 8 will show the activation of both the switches 19 and 20 by the packages 15 and 16, respectively. Under these conditions, both of the capacitance switches 19 and 20 are opened and a change in output signal is experienced by the NAND circuit 23. This is a fault signal which will indicate to the control device 24 that the assembly 10 must be stopped immediately.

The proximity switches 19 and 20 are used in conjunction with packages such as cigarette packages which have a metallic material incorporated therein. A predetermined space or distance between the package and the activating surface of the switches 19 and 20 is a characteristic associated with the particular device chosen or preselected for use in such an assembly 10.

If the packages 13 do not contain metallic foil, it may be necessary to use the embodiment of the invention such as shown in FIG. 9. Here spring biased metal flaps 25 and 26 are positioned over the proximity devices 19 and 20. As packages pass along the support means 14, the flaps 25 and 26 are pivoted into a close proximity to the switches 19 and 20 thereby causing them to produce an output signal. The rest of the operation is the same as discussed hereinabove.

While the assembly for detecting irregular feed conditions has been shown and described in detail, it is obvious that this invention is not to be considered as being limited to the exact form disclosed, and that changes in detail and construction may be made therein within the scope of the invention, without departing from the spirit thereof.

What is claimed is:

l. A combination comprising:

a. means for moving packages along a path, and

b. sensing means located along said path to detect an irregular feed condition for the packages,

c. said sensing means including two proximity switches which operate when a magnetic material is disposed a predetermined distance therefrom,

(1. said two proximity switches being interconnected to provide an interrelated condition and being laterally displaced with respect to each other by an amount effective to operate the proximity switches sequentially under normal feed conditions and to operate the proximity switches simultaneously when an irregular feed condition is present.

2. A combination as defined in claim 1 wherein means responsive to signals generated by the interrelated condition of the proximity switches of said sensing means is provided to stop the moving of packages along said path,

said responsive means including an electrical circuit means for controlling said moving means and a logic circuit connected to receive an input signal from the interrelated condition of the proximity switches and to transmit an output signal to said control circuit means,

said logic circuit being present to transmit a first output signal that allows the control circuit means to run the moving means under normal feed conditions and to transmit a second output signal that causes the control circuit means to stop the moving means under irregular feed conditions.

3. A Wrapping machine comprising the combination:

a. means for receiving a package from a package supply work station, said receiving means including means for wrapping the package,

b. means for moving packages along a package support means from the package supply work station into said receiving means, and

c. sensing means located along the package support means to detect an irregular feed condition for the packages,

d. said sensing means including two proximity switches which operate when a magnetic material is disposed a predetermined distance therefrom,

e. said two proximity switches being interconnected to provide an interrelated condition and being laterally displaced with respect to each other by an amount effective to operate sequentially under normal feed conditions and to operate simultaneously when an irregular feed condition is pres ent.

4. In a wrapping machine as defined in claim 3 wherein means responsive to signals generated by the interrelated condition of the proximity switches of said sensing means is provided to stop the moving of packages along said path,

said responsive means including an electrical circuit means for controlling said moving means and a logic circuit connected to receive an input signal from the interrelated condition of the proximity' switches and to transmit an output signal to said control circuit means,

said logic circuit being preset to transmit a first output signal that allows the control circuit means to run the moving means under normal feed conditions and to transmit a second output signal that causes the control circuit means to stop the moving means under irregular feed conditions.

5. An assembly comprising:

a. conveyor means for moving articles along a path,

b. detecting circuit means including two proximity switches for sensing an irregular feed condition for the articles moving along the path,

c. said proximity switches being interconnected with respect to eachother to provide an interrelated condition and being disposed along said path,

d. a NAND logic circuit connected to receive an input signal from the detecting circuit means and to transmit an output signal,

e. said proximity switches being connected to the NAND logic circuit and sensitive to the physical presence of a package being moved along the path a predetermined spaced distance from the switches, and

f. control circuit means being connected to the logic circuit and being responsive to a preselected output signal from the logic circuit to stop the conveyor means from moving articles along the path when an irregular feed condition is detected.

6. A combination comprising:

a. means for moving packages along a path,

b. sensing means located along said path to detect an irregular feed condition for the packages,

0. said sensing means including two transducer means which are sensitive to the physical presence of a package being moved a spaced distance therepast,

d. said two transducer means being interconnected to provide an interrelated condition and being laterally displaced with respect to each other by an amount effective to operate the transducer means sequentially under normal feed conditions and to operate the transducer means simultaneously when an irregular feed condition is present, and

e. means responsive to signals generated by the interrelated condition of the two transducer means of said sensing means to stop the moving of packages along said path,

f. said responsive means including an electrical circuit means for controlling said moving means and a logic circuit connected to receive an input signal from the interrelated condition of the transducer means and to transmit an output signal to said control circuit means,

g. said logic circuit being preset to transmit a first output signal that allows the control circuit means to run the moving means under normal feed conditions and to transmit a second output signal that causes the control circuit means to stop the moving means under irregular feed conditions.

7. The combination as defined in claim 6 wherein said logic circuit is a NAND circuit.

8. In a wrapping machine, including means for wrapping a package the combination comprising: i

a. a means for receiving a package from a package supply work station, said package to be wrapped in said wrapping means,

b. means for moving packages along a package support means from the package supply work station into said receiving means,

c. sensing means located along the package support means to detect an irregular feed condition for the packages,

d. said sensing means including two transducer means which are sensitive to the physical presence of a package being moved a spaced distance therepast,

. e said two transducer means being interconnected to provide an interrelated condition and being laterally displaced with respect to each other by an amount effective to operate sequentially under normal feed conditions and to operate simultaneously when an irregular feed condition is present, and

f. means responsive to signals generated by the interrelated condition of the two transducer means of said sensing means to stop the moving of packages along said path,

g. said responsive means including an electrical circuit means for controlling said moving means and a logic circuit connected to receive an input signal from the interrelated condition of the transducer means and to transmit an output signal to said concauses the control circuit means to stop the moving Clrcult means means under irregular feed conditions.

h. said logic circuit being preset to transmit a first output signal that allows the control circuit means to run the moving means under normal feed condi- 5 wherem log": clrcult a NAND tions and to transmit a second output signal that 9. In a wrapping machine as defined in claim 8

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1763812 *Jan 7, 1928Jun 17, 1930Samuel Olson & Company IncAutomatic safety control for conveyers
US3311224 *Nov 29, 1963Mar 28, 1967Crown Zellerbach CorpArticle-spacing inspection system
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4558776 *Jul 5, 1983Dec 17, 1985Rieter Machine Works Ltd.Apparatus for arranging cross-wound packages on an auxiliary transport belt
US6648125 *Dec 9, 2002Nov 18, 2003B E Design Automation, Inc.Apparatus for evenly spacing packages on an assembly machine
US7012210Aug 9, 2002Mar 14, 2006Lockheed Martin CorporationSingulation detection system for objects used in conjunction with a conveyor system
US7216013Aug 23, 2005May 8, 2007Lockheed Martin CorporationSingulation detection system for objects used in conjunction with a conveyor system
US20050278193 *Aug 23, 2005Dec 15, 2005Lockheed Martin CorporationSingulation detection system for objects used in conjunction with a conveyor system
DE2642490A1 *Sep 22, 1976Jul 7, 1977Azionaria Costruzioni Acma SpaVorrichtung zur ueberfuehrung von gegenstaenden mit einem vorbestimmten abstand auf einen aufnahmefoerderer
DE2952050A1 *Dec 22, 1979Jul 2, 1981Leuze Electronic KgControl of conveyor feed between work stations - has optical sensor coupled to detector circuit to control conveyor feed drive
DE3117116A1 *Apr 30, 1981Dec 2, 1982Ruediger LahneApparatus for controlling conveying systems for bulk material
EP0541392A1 *Nov 6, 1992May 12, 1993British Steel plcMetal detection
Classifications
U.S. Classification198/460.1
International ClassificationB65G43/00
Cooperative ClassificationB65G43/00
European ClassificationB65G43/00