Electrically controlled apparatus for marking objects

Abstract

An electrically controlled apparatus for marking an object traveling along a conveyer with characters such as letters and/or figures wherein code signals corresponding to the characters which are punched in by a keyboard are stored. The presence of the object along the conveyer and the speed of travel thereof are sensed by sensing means and read-out of the the storage signals is controlled by the sensed rate of travel of the object and marking devices are activated in accordance with the read-out signals. The marking devices may be arranged in a single row of five marking devices.

Parent Case Text

This application is a continuation-in-part of copending U.S. application Ser. No. 118,901, filed Feb. 15, 1971, now abandoned.

Description

The present invention relates to electrically controlled apparatus for marking objects, such as plate-on box-shaped objects, travelling along a conveyor.

In conveyor systems, objects are usually provided with code characters or symbols which are necessary for the further treatment of the objects and for their subsequent end position. The coding may be effected after the objects have been conveyed through a paint or other treatment plant.

It is an object of the present invention to provide a marking apparatus which can code the objects semi-automatically or fully automatically with readily legible characters or symbols.

The invention consists in electrically controlled apparatus for marking an object travelling along a conveyor, comprising a selectively operable marking mechanism for marking the object with a code consisting of selected characters, code selection means connected to a storage register comprising read-in means for storing code characters selected by the selection means and read-out means for receiving the stored characters and for supplying to the marking mechanism actuating signals corresponding to said characters, and control means for controlling the read-out means connected to sensing means for detecting the object on the conveyor, said control means being responsive to the sensing means detecting the object to initiate read-out of the actuating signals and controlling the rate of read-out of said actuating signals in accordance with the speed of travel of the object along the conveyor so as to cause the selected code characters to be marked on the object.

The read-in may be performed manually or automatically, for example in a fixed sequence determined by the sequence of use of the objects or the sequence of travel of the objects on the conveyor, after which the read-out means may be manually activated for automatic transfer of the previously read-in code characters to the marking mechanism as the objects are advanced by the conveyor, the control means and sensing means being arranged to activate the marking mechanism dependent upon the periodic advancement of the objects.

The marking mechanism may comprise a plurality of rows of marking devices extending substantially at right angles to the direction of travel of the object. Alternatively, it may consist of a single row of marking devices extending substantially at right angles to the direction of travel of the object. In either event, the marking devices may comprise electromagnetically or pneumatically operable marking nozzles or pistons, each of which is adapted to produce a mark on the surface of the object. The selected characters may be produced in simple manner by selected combinations of the marking devices, the combinations being predetermined by the input in the read-in means and represented by the read-out signals from the read-out means. Where the marking mechanism consists of a single row of marking devices the number of marking devices may be reduced to consist of, for example, seven of the said nozzles or pistons, which means a substantial simplification of the marking mechanism, and the apparatus may therefore be manufactured at a lower cost and be less liable to have faults such as failing electric contacts and defective marking devices.

The marking devices may be connected to the read-out means by electronic or electromagnetic devices, such as thyristors, transistors or relays, which control magnetic coils of the marking devices or magnetic valves for the pneumatic pressure-producing cylinders of the marking devices. As a result, the marking devices leave a colour spot or an impact mark on one surface of an object, substantially independent of the distance from the said surface to such end surfaces of the marking devices as are facing the said surface.

In one embodiment of the invention, the read-out means has coupling means for the read-out of combinations of selected characters both in the same and in the reverse sequence to that stored in the read-in means. Consequently, the sequence of the characters produced by the marking devices may be adjusted according to the direction of travel of the objects, for example whether the said direction is from the right to the left of the operator who is to check or read the code, in which case the first character of the code is the first to be marked on an object, or whether it is from the left to the right of the said operator, in which case the last character of the code is to be the first to be marked on the object.

Each marking device may be adapted to produce a mark consisting of a marking material containing permanently magnetisable substance, such as Fe.sub.3 O.sub.4, or a radioactive substance. As a result, the mark transferred to an object can be sensed, even though an extra coating has been applied to the object later, for example the finish coating, so that the marking is concealed behind the said coating. In this event, the marking may be read by a magnetic field detector, for example if the finish coating is provided with a thin layer of iron filings which will adhere to the finish coating when the magnetisable marking material has been subjected to permanent energization in advance, or by means of radioactive sensing means.

A lamp tableau may be connected in parallel with the read-in means, the lamps of said tableau indicating the combination of selected code characters stored in the read-in means. Thus, an operator performing the read-in may, prior to or directly following the read-in, visually check whether the selected character or the sequence is correct and, if not, be able to stop the read-in or correct parts of the coding.

A lamp tableau may also be connected in parallel with the control means, the lamps of said tableau indicating the code character available for read-out from the read-out means at each stage. Here again the operator watching the marking of the objects may, prior to the marking mechanism being activated, visually check whether a code character is the correct one and, if not, be able to stop and read-out before the code character is marked on the object.

The marking mechanism may be displaceable in the direction of travel of the object and is mechanically or magnetically coupled to the object during actuation of the marking mechanism, and be restored to its initial position upon completion of a marking operation by the action of a spring. With this arrangement, the marking mechanism when activated, is advanced with the object along the conveying path and released when the activation ceases, so that the spots marked by the marking devices are prevented from being elongated.

The code selection means may comprise a manually operable keyboard. Alternatively, it may be operable by data carriers either directly or through a computer, said data carriers bearing information on which characters are to be selected by the code selection means.

The foregoing and other objects, features, and advantages of the invention will be appearing from the following more particular description of a preferred embodiment of the invention as illustrated in the accompanying drawing wherein:

FIG. 1 a and b is a block diagram of an apparatus for marking objects according to the invention, and

FIG. 2 is a perspective view of a convenient embodiment of same in which the object to be marked consists of a sheet-formed blank.

FIG. 3 shows the prefered arrangement of the spray-nozzels. Referring to the drawing 1 is a manually operable key-board comprising push-buttons representing each of those characters that possibly may be applied if wanted, to an upper surface of an object which is to be marked.

Reference No. 2 designates a marking device mounted on a conveyor 3 (FIG. 2) which is associated with a painting plant 4. The object with this marking device 2 is to mark preferably sheet-shaped blanks 5, which have been treated in advance in said painting plant 4, with identification characters 6 either in the form of figures or letters or combinations of those. These characters or symbols may be composed as a five by seven dot matrix well known in the art, each of said dots 7 being a color spot. Each dot 7 may also be represented by an impact mark. In the event said identification characters have to be represented by color spots in a five by seven matrix, said marking device 2 could include 35 spray-guns arranged in five arrays, each array comprising seven guns and extending substantially at right angles to the direction of travel of the objects. This is indicated on the drawing by means of dotted lines.

According to the present invention it is sufficient to use a single array comprising seven spray-guns and extending substantially at right angles to the direction of travel of the object, which is indicated on the drawings by means of completed lines, and then compose the single character sequentially in five steps. The usage of only seven guns situated in one single array means a substantial simplification of the marking mechanism, and the apparatus mey therefore me manufactured at a lower cost and be less liable to have falls such as failing electric contacts and defective nozzels.

In the following description there is only referred to spray-guns even though the usage of other marking means than spray-guns falls within the scope of the present invention. The metering of paint from such a spray-gun is controlled or may be controlled by means of an electromagnetic valve as is well known by those skilled in the art. Said control of the metering may be accomplished by means of an electric impulse with a sufficient level. Such control pulses are provided by means of a circuit described in details below.

On the drawings are shown thirty-six push-buttons, each representing the capital letters from A to Z, and the figures one to nine, and further some special symbols. Each push-button of said key-board 1 is through a conductor 8 connected to a read-in unit comprising a read-only memory 9 e.g., in the form of a diode matrix comprising thirty-six input terminals and six output terminals 10 of the read-only memory in form of a binary 6-bit standard code, which is well known to those skilled in the art. The read-only memory unit is of a well known standard type available on the market and it is therefore unnecessary to describe this memory in further details. When a push-button in said key-board 1 is depressed, the associated one of those 36 conductors 8 is applied at a voltage so that the selected character becomes represented on the six output terminals 10 of said read-only memory in the form of a binary 6-bit character. This information is transferred to a shift-register 11 which, as an example, may store 10 6-bit words in the case the need for the number of characters to be marked on said sheet-shaped blank is equal to 10. The shift-register 11 may comprise six arrays of flip-flops, each array containing an arbitrary number of flip-flops and be adapted to store an arbitrary number of 6-bit words.

Each time a new character is selected by means of the key-board 1 a new 6-bit word is put into the first position of the shift-register 11 from the read-only memory 9, and the word stored in the first position of the shift-register is simultaneously shifted to the next position, position 2, and so on by any new selection of characters, i.e., depressing of a push-button on the key-board, until every position in the shift-register 11 is occupied by a 6-bit word, this means that the shift-register in the embodiment which in the actual case is described, stores ten 6-bit words.

To check that the right character is put into the shift-register 11, the information on the putput terminals of the read-only memory 9 is also transferred via six conductors, which are designated in common by reference numeral 12, to a decoder 13 comprising 36 output terminals which in common are designated by a reference numeral 14. Said decoder 13 may be designed in a similar way as the read-only memory 9 as a diode matrix so that a signal can only be present at a single one of the output terminals 14 for each combination of logic conditions on the input terminals 12 of said decoder 13. Such decoders are available as standard circuits and are well known to a person skilled in the art, and a particular description of such a decoder is therefore not necessary.

The 36 output terminals of the decoder 13 are each connected to one lamp in a lamp tableau 15, which is able to visualize the thirty-six characters which can be selcted by means of the keyboard 1. Consequently, by depressing a push-button on the key-board, one will instantly have a check by said lamp tableau 15 on that character which presently is read-in in the shift-register 11. In the event a wrong character has been read-in in the register, all six cells of the first position of said register are resetted by means of a reset switch 16 followed by a new read-in of the right character by depressing the right push-button on the key-board 1.

To obtain an indication of the moment in which all ten positions of the shift-register are occupied, the read-only memory 9 has been provided with an extra output terminal 17, which delivers an impulse to a counter 18 each time a push-button in the key-board 1 is depressed, thereby initiating a read-in in the shift-register 11 of a new 6-bit word. Said counter is advantageously provided with a digit display.

When the last position in the register 11 has been occupied by a 6-bit word, and the counter 18 displays the FIG. 10, said register contains all the characters which are used to mark one single object.

If more than 10 characters are needed in order to mark a single object, the number of positions in the shift-register 11 can be extended and it is of course possible to choose a counter 18 with a greater counting capacity.

The information stored in the shift-register is now transferred via six output conductors, which are designated in common by reference numeral 19 to a greater store 20, which is designed in a similar way as the register 11, but has a greater storing capacity. This store 20 has preferably a capacity great enough to store a number of characters which will be used in order to mark at least 5-10 objects, depending on how many characters that are used to mark a single object.

The transfer of information from the shift register 11 to the subsequent store 20 is accomplished by forwarding to all the clock-input terminals of the flip-flops, which constitute these two shift-registers, a clock-impulse which is delivered from a clock-impulse generator 21, which can be actuated by means of a switch 22 in a well known manner. Thus delivery of 10 clock-impulses is sufficient to transfer the entire information stored in the shift-register to the store 20, which also is built up as a shift-register in a similar way as the first mentioned shift-register. It should be recognized that the read-in and the read-out of information is performed in parallel. The six output terminals 23 of the store 20 is connected to a third read-only memory 24. This memory is further provided with three input terminals 25, and seven output terminals 26, and is of a standard type, well known to those skilled in the art. It is also called a character generator. This unit delivers at its output terminals 26, 7-bit marking data when an address comprising 6+3 bits is present on the input terminals which is designated in common by the reference numerals 23 and 25.

The output terminals 26 are connected to a time-unit 27 which in turn, via conductors 28, is connected to a group of amplifiers 29, the output terminals 30 of which are connected individually to a solenoid valve in the spray-guns which form the marking mechanism 2.

The time-unit 27 includes seven monostable multivibrators, which have to determine the length of a time-interval in which the solenoid valves have to be actuated, while the amplifiers 29 of course will amplify the amplitudes of these impulses to the necessary level.

The pulse duration for said monostable multivibrators 27 is so short that a particular circuitry to coordinate the possible displacement of this marking mechanism with the movement of the sheet which is being marked, is rendered superflous. The marking mechanism is fixedly mounted on the frame of the conveyor, and the marking procedure takes place while the objects are moved forwardly by the conveyor. This has no influence on the legibility of the applied characters. The input terminals 25 of the read-only memory 24 are connected to a counter 31 which is so disposed that it sets, in a 3-bit code, which of the steps 1-5 that are actual at the present moment during the sequential elaboration of that character which is represented by the six logical conditions on the input terminals 23.

The counter 31 further delivers, via a conductor 32, clock-impulses to the shift-register 20. The counter receives counting impulses from a timing-mechanism 33, and may be started by means of a sensing device 34 which delivers to the counter 31 a starting impulse via a conductor 35 by detecting of an object 5 which is to be marked.

FIG. 2 is a perspective view of an embodiment of the apparatus for marking sheet-shaped blanks according to the invention disposed in conjunction with the conveyor and painting plant 3,4 in which the sheet-shaped blank 5 is moved in a direction indicated by an arrow 40 by means of conveyor rollers 36 which are carried by shafts 37, supported in the girders 38 of the plant and in driven connection with each other for example through chain drive and chain wheels (not shown). The sensing means 34 senses the front edge 41 of the sheet-shaped blanks to determine the moment of introduction of the blank into the active field of the marking mechanism and thereby starting the counting cycle of a counter 31, the counting speed of which is determined by the timing-unit 33. This timing-unit 33 includes, as indicated in FIG. 2, a winged wheel which is driven at the same rotational speed as a conveyor roller 36. The timing-unit shall not be discussed in details as it is disclosed in details in applicant's own U.S. Pat. No. 3,566,828. This unit transmits time impulses to the counter 31.

In this way the output speed from the store 20 and the setting of the solenoid valves of the spray-guns are adapted to that speed, by which the object to be marked is moved by the conveyor.

In a preferred embodiment of the invention the number of spray-guns has been reduced to five, thus saving yet another two spray-guns.

The best legible results are obtained if the five spray-guns or their nozzels are arranged in a pattern which is shown in FIG. 3. The control of the solenoid valves of these spray-guns is accomplished by using the same principles as discussed above. Only a few modifications in the described circuitries have to be set up, the nature of which modifications are obvious to a person skilled in the art. While the invention has been particularly shown and described with reference to a prefered embodiment thereof, it will be understood by those skilled in the art, that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.

Claims

What we claim is:

1. In a electrically controlled apparatus for marking an object travelling at a speed which may vary along a conveyer, having a selectively operable marking mechanism for marking the object with a code consisting of selected characters such as letters and/or figures, code selection means connected to a storage register through read-in means for storing code characters selected by said selection means and read-out means for reading out the stored characters from said storage register and for supplying to the marking mechanism actuating signals corresponding to said characters, first sensing means for sensing the presence of said object along said conveyer, second sensing means for sensing the speed of travel of said object along said conveyer, and control means connected to said first and second sensing means and to said storage register, said control means being responsive to the presence of said object along said conveyer as detected by said first sensing means for causing said actuating signals to begin to read out from said storage register, said control means further including means for controlling the rate of read-out of said actuating signals in accordance with the variable speed of travel of the object along the conveyer as sensed by second sensing means so that said characters are marked on said object at a rate dependent on the rate of travel of said object.

2. The apparatus of claim 1 wherein said control means comprises a counter having clock pulses inputted thereto, the rate of occurrence of said clock pulses being controlled by said second sensing means in accordance with the detected speed of travel of said object.

3. The apparatus of claim 1 wherein a bank of display lamps is connected to said read-in means through decoder means for displaying the selected characters.

4. Apparatus as claimed in claim 1 in which the marking mechanism consists of a single row of marking devices extending substantially at right angles to the direction of travel of the object, said single row of marking devices comprising 5 devices.

5. Apparatus as claimed in claim 1 wherein the mark produced by each marking device contains either a permanently magnetizable substance or a radioactive substance.