Gripper jaw insert mistake detector

Abstract

A device is disclosed for detecting "double-or-miss" mistakes of an inserting machine. The device comprises the inserting machine's gripper jaws, a leaf spring which is attached to one of the gripper jaws and an electronic detector. The leaf spring's position is determined by the extent to which the jaws are open. The leaf spring forms a movable electrode which is positioned between first and second electrodes which form a part of the electronic detector. When there is a miss the leaf spring makes contact with either the first or the second electrode and when there is a double the leaf spring makes contact with the other electrode.

Parent Case Text

BACKGROUND OF THE INVENTION

This is a continuation-in-part of commonly assigned U.S. patent application Ser. No. 62,912, now U.S. Pat. No. 3,744,787, filed on Aug. 11, 1970 and entitled "GRIPPER JAW INSERT MISTAKE DETECTOR". In accordance with a notice in Volume 859 of the Official Gazette dated Feb. 11, 1969, the subject matter of application Ser. No. 62,912 is incorporated herein by reference.

Description

The referenced application as well as this invention relate generally to mail inserting machines and more particularly to devices which detect whether an inserting machine has missed an insert or pulled to many inserts. Reference is made to U.S. patent application Ser. No. 62,912 for a discussion of the various disadvantages of prior art insert mistake detection devices as well as for a discussion of insertion machines per se.

While the insert mistake detection device described in the referenced patent application has been found to be highly satisfactory in solving many of the disadvantages of prior art devices that perform the same function, it has certain areas that are still subject to improvement. For example, while it is very uncomplicated in construction it is desirable to provide a device that is even less complicated. In addition, while its linkage system has been found to be very stable, such stability still can be improved upon. Further, while it is easy to adjust for different size inserts, it is desirable to make such adjustments still easier.

Therefore it is an object of this invention to provide an insert mistake detector suitable for use in an insertion machine that is even less complicated in construction than is the detector described in U.S. patent application Ser. No. 62,912 and has an even more stable linkage arrangement than does that detector.

It is another object of this invention to provide an insert mistake detector suitable for use in an insertion machine that is still easier to adjust for different size inserts than is the insert mistake detector described in U.S. patent application Ser. No. 62,912.

SUMMARY OF THE INVENTION

In accordance with principles of this invention, an electrically conductive element is rigidly affixed to the movable jaw of a movable jaw gripper forming a part of an inserting machine. The electrically conductive element is positioned between first and second electrodes which are connected to an electrical detection circuit. Because of its rigid connection, the electrically conductive element follows the movement of the movable jaw and comes into contact with one or the other of the electrodes when the jaw is either open too wide or closed entirely. The first situation (open too wide) occurs when too many inserts are gripped and the second situation (enclosed entirely) occurs when no insert is gripped. When such contact occurs, the electrical detection circuit is energized so that appropriate corrective action can be taken.

In accordance with other principles of this invention, the "quiescent" position of the electrically conductive element is adjustable by screw rotation. Moreover, screw rotation adjustment of one of the electrodes is provided. It will be appreciated that screw rotation allows the invention to be easily adjusted whereby it is suitable for use with inserts having thicknesses that vary over a wide range.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing objects and many of the attendent advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description of a preferred embodiment of the invention when taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a partially schematic side elevational view of portions of a mail inserting machine embodying the invention;

FIG. 2 is a fragmentary side elevational view of an inserting arm assembly in the proper attitude for detecting a "miss"; and,

FIG. 3 is a fragmentary side elevational view of an inserting arm assembly in the proper attitude for detecting a "double".

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates a mail inserting system that includes an insert hopper 11, an inserting arm assembly 13, and a mistake detection circuit 15. The detection circuit is surrounded by a dashed line in the figure.

The insert hopper 11 contains a pile of inserts 17 (for example, bills) which are to be picked up by the inserting arm assembly 13. An insert separator 12, having a separating point 14 moves in the direction shown by arrows 16. This movement causes the separating point 14 to wedge between the lowermost insert in the pile 17 and separates that insert from the rest of the pile.

The inserting arm assembly 13 generally comprises: a gripper arm 19, a gripping jaw 21, a gripping jaw spring 23, an indicator mechanism 25, and a terminal block 27.

In the illustrated embodiment, the gripper arm 19 is made of one solid piece of electrically conductive material and rotates at its upper end about a gripper arm axis 31. The lower end is crooked so as to form a lower stationary jaw 33.

The gripping jaw 21 has a gripper end 35 and a lever spring end 37 and is affixed to a jaw pivot or axis pin 29 which is rotatably mounted on the gripper arm 19. In this regard, the gripping jaw 21 and axis pin 29 are adapted to rotate so that the gripper end 35 closes on the lower stationary jaw 33 and grips an insert 34 between the gripping jaw 21 and the lower stationary jaw 33. The gripper jaw spring 23 is tensioned between the lever spring end 37 of the gripping jaw and a spring stud 39 mounted on the gripping arm 19 to bias the gripping jaw 21 closed.

The indicator mechanism 25 comprises an electrically conductive clamped arm 41, an indicator leaf spring 43, a clamping screw 45, and an indicator adjusting screw 47. The clamped arm 41 is generally C shaped at one end and is clamped about the axis pin 29 by the clamping screw 45. The indicator leaf spring follows the outer periphery of the clamped arm 41 about its C shaped end and terminates in an upwardly extending contact end 51. The clamping screw 45 holds the indicator leaf spring 43 tightly against the clamped arm 41 at its lower end 49. The contact end 51 of the indicator leaf spring 43 is in direct electrical contact with the clamped arm 41 which, through the axis pin 29 and the gripper arm 19, is grounded to the inserting machine.

The indicating adjusting screw 47 is threadably mounted in the clamped arm 41 and the end thereof makes contact with the indicator leaf spring 43 so as to control the position of the contact end 51 of the indicator leaf spring. Thus, the normal position of the contact end 51 of the indicator leaf spring 43, with respect to the clamped arm 41, is adjusted by turning the indicating adjusting screw 47 inwardly and outwardly. A first cinch screw 48 allows the indicating adjusting screw 47 to be locked in place.

The terminal block 27 comprises a detector leaf spring 53, an insulator block 55 and an aluminum contact block 57. As seen in FIG. 1, the detector leaf spring 53 and the aluminum contact block 57 are mounted on opposite sides of the insulator block 55 and are fixedly attached thereto by bolts 58, the upper one of which creates electrical contact between the detector leaf spring 53 and the aluminum contact block 57. The detector leaf spring 53 is also attached to the insulator block 55 by a terminal screw 59 at its upper end. A pair of bolts 60 fixedly attach the insulator block 55 to the gripper arm 19. It will be appreciated that while the insulator block 55 is mounted directly on the gripper arm 19, the detector leaf spring 53 and the aluminum contact block 57 are electrically insulated from the gripper arm 19 by the insulator block.

The lower end of the detector leaf spring forms a contact end 61 and is positioned adjacent to the contact end 51 of the indicator leaf spring 43. A contact screw 63 is threadably mounted in the aluminum contact block and its end forms a contact point 65 that is adjacent to the contact end 51 of the indicator leaf spring 43 on the opposite side thereof from the contact end 61 of the detector leaf spring.

The mistake detection circuit 15 includes: a detector circuit 67; a power source 71; and, a detection-period gate 73. The detector circuit 67 is connected through the detection-period gate to the power source 71 and comprises any suitable alarm or cut-off control that will indicate the commission of a mistake by the inserting machine. For example, it can be a light, buzzer, mechanism for cutting off the inserting machine, etc. The detection-period gate 73 is closed during a "detection-period" and open at other times. In this regard, a detection-period is determined by the angular location of the gripper arm 19. That is, a linkage (schematically illustrated by a dashed line 75) located between the detection-period gate 73 and the gripper arm 19 enables the detection-period gate 73 to sense the angular location of the gripper arm 19. For example, in one embodiment, the detection-period gate 73 closes its portion of the mistake detection circuit 15 when the gripper arm 19 has rotated 20.degree.-30.degree. away from the hopper 11. Similarly, the linkage opens the detection-period gate 73 just before the gripping jaw 21 releases the insert, approximately 160.degree. from the hopper.

In operation, the insert separator 12 uses separating point 14 to separate a bottom insert from the rest of the pile 17 so that the gripping jaw 21 only grabs one insert. If the separator 12 separates two or more inserts from the rest of the pile, rather than one, there is a double because the gripping jaw will pick up more than one insert. Conversely, if the separator 12 does not separate any inserts from the rest of the pile there is a miss.

At the same time as the insert separator is performing its separating function, the gripper arm 19 is rotating as shown by arrow 76, about the gripper arm axis 31. During the rotation period in this direction mistakes are not detected, because the detection-period gate 73 is constructed so as to hold the mistake detection circuit 15 "open". However, once the gripping jaw 21 picks up (or misses) one or more inserts and the gripper arm 19 has moved in a counter-clockwise direction approximately 20.degree.-30.degree. from the hopper 11, the detection-period gate 73 closes its portion of the mistake detection circuit 15. This situation is shown in FIG. 1, i.e., the inserting arm assembly 13 has just returned from the hopper 11 where it grabbed an insert 34 and the detection-period gate 73 is closed. The biasing of the gripping jaw 21 against the lower stationary jaw 33 by the gripping jaw spring 23 allows the insert to be firmly held therebetween.

The position of the contact end 51 of the indicator leaf spring 43 is determined by the position of the gripping jaw 21 because: the gripping jaw is clamped to axis pin 29; the clamp arm 41 of the indicator mechanism 25 is directly clamped to the axis pin 29; and, the indicator leaf spring 43 is held in a fixed position relative to the clamped arm 41 by the clamping screw 45 and the indicating adjusting screw 47. If the gripping jaw 21 has grabbed only one insert, as is the case in FIG. 1, the contact end 51 of the indicator leaf spring 43 does not make contact with either the contact end of the detector leaf spring 61 or the contact point 65 of the contact screw 63, hence, the mistake detection circuit remains open and the detector 67 is not actuated.

FIG. 2 shows the arrangement of the various parts when there is a miss. Here it can be seen that the gripping jaw 21 is in a completely closed position, thus, the axis pin 29 and the clamped arm 41 are rotated further in a counter-clockwise direction than they are in FIG. 1. As the gripping jaw 21 closes in this manner, the clamp arm 41 causes the contact end 51 of the indicator leaf spring 43 to rotate in a counter-clockwise direction until it contacts the contact end 61 of the detector leaf spring 53. This completes the circuit to the detector 67. The detector is energized when the detection-period gate 73 is closed, such closure occuring when the gripper arm 19 comes within the foregoing range during it's return stroke. Preferably, when the indicator leaf spring 43 makes contact with the contact end 61 of the detector leaf spring, the detector leaf spring flexes away from the insulator block 55 as indicated in FIG. 2. Thus good electrical contact is assured.

FIG. 3 shows the detector when there is a double. Here, the gripping jaw 21 and the axis pin 29 are rotated further in a clockwise direction than they are in FIG. 1. Because the double inserts hold the gripping jaw 21 wider open than does a single insert, the contact end 51 of the indicator leaf spring 43 makes contact with the contact point 65 of the indicating adjusting screw 63. This contact completes the circuit through the detector 67 which is again energized when the gripper arm 19 comes within the foregoing range. Preferably, when the contact end 51 of the indicator leaf spring 43 makes contact with contact point 65 of the indicating adjusting screw 63 it flexes away from the clamp arm 41 and the indicating adjusting screw 47 so that good electrical contact is provided.

The above described detector is adjusted as follows: with the thinest insert that is expected to be inserted by the inserting machine held between the gripping jaw 21 and the lower stationary jaw 33 the indicating adjusting scerw 47 is screwed in, or to the left, pushing the contact end of the indicator leaf spring 43 before it until the contact end 51 just contacts the contact end 61 of the detector leaf spring. A continuity light may be used to detect this contact. The indicating adjusting screw 47 is then backed out, or moved to the right, about one-eighth of a turn which leaves a small gap between the contact end of the indicator leaf spring 51 and the contact end 61 of the detector leaf spring. The contact screw 63 is then screwed in, or to the left, until its contact point 65 just contacts the right face of the indicator leaf spring 43. Again, a continuity light may be used to detect this contact. The contact screw 63 is then backed out, or moved to the right about one-eighth of a turn, thus, leaving a gap between the contact point 65 and the contact end 51 of the indicator leaf spring 43. The detector is now set for that thickness of insert, and if an insert is missed or a double is gripped, the contact end 51 of the indicator leaf spring 43 will contact either the contact end 61 of the detector leaf spring or the contact point 65 of the contacting screw 63, as determined by the situation.

If it is desired to reset the detector for a thicker insert, the contact screw 63 need not be adjusted again. It is only necessary to place the thicker insert in the jaws and adjust the indicating adjusting screw 47 until the contact end 51 of the indicator leaf spring 43 is located in the desired position. Thus, the adjustment of this detector for various insert thicknesses is easily accomplished by turning just one knob.

It will be understood by those skilled in the art that the detector described above is relatively uncomplicated in that there is very little linkage between the movable gripper jaw and the indicator element. Also, the parts for the above described detector are convenient to manufacture. Further, to adjust the above described detector to accept various sizes of inserts requires movement of only one adjusting screw, which is clearly an advantage over most prior art insert mistake detectors.

While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention. For example, a separate miss detector may be electrically coupled to the detector leaf spring and a separate double detector may be electrically coupled to the aluminum contact block. As described in the referenced U.S. patent application (Ser. No. 62,912) both the miss and double detectors are connected to the detection-period gate. In this manner a separate indication of either a miss or a double is provided.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A mistake detector for inserting machines utilizing at least one gripper jaw assembly movable toward and away from an insertion station and comprising a first jaw and a second jaw rotatably attached to one another in a manner such that said jaws are rotatable toward and away from each other so as to form an insertion gripping gap therebetween, said mistake detector comprising:

a leaf spring fixedly attached to one of said jaws so as to rotate with said one jaw relative to the other jaw of said gripper jaw assembly;

spaced apart first and second electrodes fixedly attached to the other of said jaws a portion of said leaf spring lying between said electrodes and normally occupying an intermediate position between said electrodes whereby rotation of said one jaw causes said leaf spring to contact either said first or said second electrode depending upon the number of inserts being gripped by said gripper jaw assembly; and,

an electronic detector and indicator means electrically connected to said electrodes and to said leaf spring for detecting and indicating when one of said electrodes is in contact with said leaf spring by completing an electrical circuit which includes said electrodes and said leaf spring.

2. A mistake detector as claimed in claim 1 wherein said leaf spring contacts the first of said electrodes when said gripper jaw assembly is not holding any inserts.

3. A mistake detector as claimed in claim 2 wherein said leaf spring contacts the second of said two electrodes when said gripper jaw assembly is gripping more than a desired number of inserts.

4. A mistake detector as claimed in claim 3 including a mechanically operated electronic gate forming a part of said electronic detector and indicator means, said gate being electrically connected in series with said leaf spring and said contacts and mechanically coupled to said gripper jaw assembly so as to be opened and allow current to flow through said electronic detector and indicator means when said gripper jaw assembly is in a predetermined position and moving in a predetermined direction toward and away from an insertion station.

5. A mistake detector as claimed in claim 4 wherein said electronic gate is open when said gripper jaw assembly is returning from an insertion station.

6. A mistake detector as claimed in claim 5 including:

a shaft, said shaft being fixedly attached to said first jaw so as to change position in accordance with the number of inserts being gripped by said gripper jaw assembly;

an arm fixedly clamped to said shaft, said leaf spring being attached to said arm; and,

a screw, said scew mounted in a threaded aperture in said arm so as to impinge on and move said leaf spring with respect to said arm and thereby adjust the position of said leaf spring.

7. A mistake detector as claimed in claim 6 including:

an insulator block fixedly attached to said second jaw, said first contact being mounted on one side of said insulator block and said second contact being mounted on the other side of said insulator block; and,

a second screw, said second screw forming a portion of said second contact and being mounted in a threaded aperture in said second contact so as to be movable with respect to said leaf spring to thereby adjust the spacing between said second contact and said leaf spring.

8. A mistake detector as claimed in claim 1 including a mechanically operated electronic gate forming a part of said electronic detector and indicator means, said gate being electrically connected in series with said leaf spring and said contacts and mechanically coupled to said gripper jaw assembly so as to be opened and allow current to flow through said electronic detector and indicator means when said gripper jaw assembly is in a predetermined position and moving in a predetermined direction toward and away from an insertion station.

9. A mistake detector as claimed in claim 1 including:

a shaft, said shaft being fixedly attached to said first jaw so as to change position in accordance with the number of inserts being gripped by said gripper jaw assembly;

an arm fixedly clamped to said shaft, said leaf spring being attached to said arm; and,

a screw, said screw mounted in a threaded aperture in said arm so as to impinge on and move said leaf spring with respect to said arm and thereby adjust the position of said leaf spring.

10. A mistake detector as claimed in claim 1 including:

an insulator block fixedly attached to said second jaw, said first contact being mounted on one side of said insulator block and said second contact being mounted on the other side of said insulator block; and,

a second screw, said second screw forming a portion of said second contact and being mounted in a threaded aperture in said second contact so as to be movable with respect to said leaf spring to thereby adjust the spacing between said second contact and said leaf spring.