Title:
COUNTING DEVICE FOR FOLDED SHEETS, PARTICULARLY FOLDED NEWSPAPERS
United States Patent 3571574


Abstract:
The counting device according to the invention is particularly adapted to count newspapers travelling in imbricated arrangement on a conveyor means past a feeler which upon being actuated by each successive protruding folding edge of the overlapping newspapers produces an electrical pulse to be registered by a counter. Means are provided for blocking the registering operation of the counter during a period of time corresponding to the time of passage of a fraction of the distance between two successive folding edges past said feeler.



Inventors:
GERBER WALTER
Application Number:
04/645758
Publication Date:
03/23/1971
Filing Date:
06/13/1967
Assignee:
FERAG FEHR & REIST AG.
Primary Class:
Other Classes:
235/98B, 235/98R, 377/30
International Classes:
G06M7/10; H03K21/02; G06M7/00; (IPC1-7): G06M7/06
Field of Search:
235/92 (33
View Patent Images:
US Patent References:
3239138Electronic article counting device1966-03-08Loeffler
3024985Sheet counters1962-03-13Heil
2208270Counting mechanism1940-07-16Grout



Primary Examiner:
Wilbur, Maynard R.
Assistant Examiner:
Thesz Jr., Joseph M.
Claims:
I claim

1. A counting device for folded paper sheets, particularly for a succession of folded newspapers travelling on conveyor means in imbricated relation past a feeler which upon being actuated by each successive protruding folding edge of the paper sheets, produces a pulse to be registered by a counter, wherein the improvement comprises means for blocking said counter during a period of time corresponding to the passage of a fraction of the distance between two successive folding edges past said feeler, said means including a tilting switch means acted on by the pulses of the feeler, produced upon passage of a protruding folding edge past the feeler, to tilt from a normal condition thereof into another condition, said tilting switch means upon changing from said normal condition to the other said condition thereof producing a pulse fed to the counter, means for tilting the actuated tilting switch means back to normal condition, the latter said means being operative with a time delay corresponding to said period of time required for the passage of said fraction of the distance between two successive folding edges past said feeler, said tilting switch means comprising a monostable multivibrator having a retention time in said other condition which is in excess of the longest period of time required for the travel of two successive folding edges past said feeler.

2. A counting device according to claim 3, and comprising 1, wherein said means for tilting the tilting switch means back to normal condition comprises a second counter operative to return said multivibrator to normal condition, said second counter receiving pulses at a frequency proportional to the frequency of the passage of said folding edges past said feeler, said second counter being responsive to a predetermined number of counted pulses to emit an output pulse fed to said multivibrator.

3. A counting device according to claim 2, in which said second counter includes a decade and a preselection device for presetting said decade to said predetermined number of pulses to be counted for the emission of an output pulse.

4. A counting device according to claim 1, wherein said means for tilting the tilting switch means back to normal condition comprises a second feeler, the two feelers being adapted to emit pulses when actuated by the folding edges of said succession of folded sheets, said two feelers being arranged in series in the direction of travel of said conveyor means to be actuated in timed succession by the protruding folds of said sheets, the pulse emitted by the first actuated feeler being operative to tilt said tilting switch means into said other condition, and the pulse emitted by the second actuated feeler being operative to restore said tilting switch means to normal condition.

Description:
This invention relates to a counting device for sheets, particularly folded paper sheets, such as folded newspapers travelling in imbricated arrangement on a conveyor means past a feeler which upon being actuated by each successive protruding folded edge of the imbricated arrangement produces a pulse to be registered by a counter.

Counting devices of the above mentioned type have the inconvenience that counting mistakes will be registered when the folds of the imbricated newspapers are not clearly defined. The paper surface between two successive fold edges of the imbricated arrangement may show protruding bulges, undulations or wrinkles the size of which may approach the level of the folded edges, so that the feeler not only is responsive to the succession of folds, but also to such undesired protuberances and thus registers additional pulses resulting in erroneous counting indications. Such errors particularly occur when the newspapers to be counted are relatively thin, so that the difference in level between the folding edges and the lowest point of the imbricated arrangement is small, or when the newspapers are quite thick and undulations are formed in the paper in proximity to the fold.

An object of the invention is to provide a counting device of the above mentioned type which avoids such counting errors. The improvement according to the invention comprises means for blocking said counter and preventing registration of pulses during a period of time beginning with the passage of each successive folding edge past said feeler and corresponding to the passage of a fraction of the distance between two successive folding edges past said feeler.

The invention will now be more fully described with reference to the accompanying diagrammatic drawings in which:

FIG. 1 is a diagrammatic illustration of a counting device comprising a monostable multivibrator,

FIGS. 2a, 2b, 2c, 2d, 2e and 2f represent a pulsing program of the counting device shown in FIG. 1,

FIG. 3 is a diagram of a modification of the device including a monostable multivibrator,

FIG. 4 represents a diagram of a further modification of the counting device.

Referring to FIG. 1, the diagrammatically represented counting device comprises a feeler 1 having a feeler needle 1a which is adapted to slide over a succession of folded newspapers 4 supported in imbricated overlapping arrangement on a conveyor means, for example an endless conveyor band 2. The direction of movement of the conveyor band is indicated by the arrow 3. The folded edge 4a of each newspaper 4 forms a protuberance which will actuate the feeler element 1a when the succession of newspapers moves past this element, and at each actuation of the feeler element 1a the feeler 1 produces an electric pulse. The distance between two successive folding edges or protuberances 4a of the conveyed newspapers is designated by 5, while the reference numeral 6 indicates a fraction of the distance 5 rearwardly of each folding edge, over which fraction the newspaper may have wrinkles, pleats, creases or undulations in the paper, having such a height above the normal paper surface of the feeler that they will also actuate the element 1a and produce undesired pulses.

The output of the feeler 1 is connected to a pulse shaper 7 which serves to transform the irregular shaped pulses produced by the feeler 1 into rectangular pulses of corresponding width but of constant amplitude. The pulse shaper 7 also produces a differentiation of the ascending flank of the pulses. The resulting pulse is fed to a successive monostable multivibrator 8 which normally is in its inoperative position. By a differentiated pulse of the pulse shaper 7 it is tilted into its other position and thereby produces a pulse fed to the successive amplifier 9 from which the amplified pulse is delivered to a counter 10, for example an electromagnetic or an electronic counter having optical indicator means to indicate the FIG. values.

The retention time of the monostable multivibrator 8 in its tilted position, i.e. its time constant is greater than the longest period between two successive folds 4a of the newspapers passing past the feeler element 1a. For determination of the value of the time constant, the longest occurring distance 5 between successive folds 4a and the lowest travelling speed of the conveyor band 2 are to be considered.

During the period in which the multivibrator 8 remains tilted out of its normal condition in its other condition, the multivibrator is not responsive to further pulses arriving at the input. Particularly, any such further pulses cannot arrive at the counter 10, since counting pulses are produced only when the multivibrator 8 is tilted out of its normal condition. Accordingly, if interference pulses are produced by the feeler 1 at small time intervals after the production of the main pulse by the folds 4a of the newspapers, the counter 10 is blocked against reception of such pulses, due to the monostable multivibrator being in its tilted condition.

In order to enable the counter 10 to register the main pulse produced by the passage of the next following fold 4a past the feeler element 1a, the multivibrator 8 must be restored in time to its normal position. To obtain this result the following further means shown in FIG. 1 are provided. Such means comprise a pulse generator 11, producing pulses with a frequency proportional to the frequency of passage of the folds 4a past the feeler element 1a, accordingly also proportional to the speed of the conveyor band 2 and inversely proportional to the distance 5 between the folds 4a. The pulse frequency, however, as a rule is maintained constant. A pulse generator suitable for the device of this invention can be formed by a photoelectric apparatus having a segment shutter, a light source and a photoelectric cell, or a corresponding electromagnetic arrangement.

The pulses produced by the pulse generator 11 arrive at a pulse shaper and pulse gate 12 and then at a pulse counter 13. This latter comprises one or more counting decades 14 and a preselection device 15 which serves to set the counter to a number at which the decades 14 will produce an output pulse. A restoring circuit arrangement 16 is further provided for restoring the counting decade 14 to zero by a line 17 when it arrives at the set number. The output pulse of the counter 13 passes through a line 18 to the multivibrator 8 and restores this latter to its normal condition.

In order to prevent the pulse counter 13 from counting the pulses immediately after restoring the decade 13 to zero, the pulse gate 12 is provided which is controlled by the multivibrator 8 as schematically represented by the line 19. When the multivibrator tilts from its normal position into the other position, the pulse gate 12 is opened, so that the pulses of the pulse generator 11 may arrive to the input side of the counting decade 14. The pulse gate 12 is closed again when the multivibrator tilts back, so that feeding of pulses to the counting device 13 is blocked.

The manner of operation of the counting device 13 is explained by reference to FIGS. 2a to 2f of the drawings. FIG. 2a represents the pulses at the output of the feeler 1. The main pulse 20 produced by the feeler owing to the passage of a fold 4a of the newspapers may be followed by one or more interference pulses 21 due to the presence of an irregular surface of the newspaper, the registering of such interference pulses having to be prevented.

FIG. 2b represents the pulse 22 as transformed by the pulse shaper 7, which pulse is rectangular and of constant amplitude. The rectangular pulse 22 is further transformed by differentiation in the impulse shaper 7 into a narrow pulse 24 (FIG. 2c) having a steep ascending flank. The interference pulses 21 also will be transformed in similar manner to pulse shapes indicated at 23 and 25.

FIG. 2d represents the the of the monostable multivibrator 8, for example by the voltage at an electrode of a tube or a transistor. The zero line 0 corresponds to the stable normal condition of the multivibrator, while the unstable tilted condition is represented for example by an electrode voltage 26. The multivibrator is tilted by the pulse 24. The voltage rise occurring upon tilting passes to the counter 10 (FIG. 1) for registration. The time constant of the multivibrator is so chosen that the voltage 26 per se is retained at least until the arrival of the next following pulse 24. The interference pulses have no effect since they cannot produce any change of the voltage 26, and therefore the counter 10 is not actuated by these pulses.

FIG. 2e represents the output pulses of the pulse generator 11 after transformation into narrow rectangular pulses 27. In the described example, where the distance 5 between two folds 4a is about 4 centimeters, the pulse generator produces ten counting pulses. FIG. 2f represents the pulses produced by the pulse generator 11 at the input side of the counter 13. The preselector 15 is so adjusted that the decade 14 counts 7 pulses. By the seventh pulse 28 the multivibrator is restored to normal position, so that the voltage 26 (FIG. 2d) drops to zero. At the same time the tilting of the multivibrator produces blocking of the pulse gate 12, so that no further pulses 27 of the pulse generator 11 can arrive at the counter 13. Only upon appearance of the following pulse emitted by the feeler 1 and transformed into a pulse 24 (FIG. 2c) the gate 12 is opened again by the tilting of the multivibrator 8 (FIG. 2d), whereafter the described operation is repeated, since the last pulse 28 (FIG. 2f) also caused the counter decade 14 to be restored to zero. Setting of the number of pulses to be counted in the decade 14, by means of the preselector 15, accordingly results in predetermining the length of the distance 6 (FIG. 1) through which the registering counter 10 shall be blocked.

FIG. 3 represents a modification of the counting device. This device again comprises a feeler 1 with a feeling element, a pulse shaper 7, a monostable multivibrator 8, an amplifier 9 and a registering counter 10. The operation of the multivibrator is the same as described with reference to FIG. 1. By the effect of a pulse produced by the feeler 1 and transformed by the pulse shaper the multivibrator is tilted, so that further interference pulses which may be emitted by the feeler do not exert any action on the counter.

The restoring of the multivibrator to normal condition before arrival of the next following main pulse is obtained in the manner exposed hereafter.

A further feeler 29 is provided corresponding to the feeler 1 but which is displaced in the direction of travel of the newspapers which are not shown in this example, through the distance 6, this distance being smaller than the distance between successive folds 4a of the newspapers. The pulse produced by the feeler 29 is suitably transformed by a further pulse shaper 30 and then fed to the monostable multivibrator 8 which is thereby tilted back into normal position. The feeler 29 accordingly serves only the purpose of restoring the multivibrator, but not of counting. The pulse counter in this example is more simple with respect to electrical equipment than that of FIG. 1, but requires a more elaborate mechanical structure owing to the presence of a second feeler 29.

The modification shown in FIG. 4 comprises again a feeler 1, a pulse shaper 7, a multivibrator 8, an amplifier 9 and a counter 10. The reference numeral 31 designates a Tacho-Generator which is driven in synchronism with the travelling speed of the newspapers on the conveyor and accordingly delivers a voltage proportional to this speed. This voltage will be used to charge an adjustable retardation means 32 which after having attained a certain charging voltage delivers a pulse to a pulse amplifier 33, the output pulse passing through the line 18 actuates the multivibrator and tilts it back to normal condition. The retardation means 32 in turn is controlled by the multivibrator 8 through the line 19 and a switch step 34 in such a manner that the charging of the retardation means 32 is blocked so long as the multivibrator is in its normal position. This arrangement accordingly does not produce the restoring pulse by a counting of secondary pulses (counter 13 of FIG. 1), or as a result of a control pulse being produced by a feeler sensing the folds 4a of the newspapers at a displaced point (FIG. 3), but as a result of a pulse directly dependent on the main pulse and released after a certain time delay which is proportional to the travelling speed of the newspapers, the respective constant of proportionality being set on the retardation means itself.