US3905325A

US3905325A - Envelope flap moistening apparatus

Info

Publication number: US3905325A
Application number: US513526A
Authority: US
Inventors: Walter T Labore; Richard A Hallenbeck
Original assignee: Pitney Bowes Inc
Current assignee: Pitney Bowes Inc
Priority date: 1974-10-10
Filing date: 1974-10-10
Publication date: 1975-09-16
Anticipated expiration: 1992-09-16

Abstract

A moistening apparatus for wetting the gummed surface of an envelope flap. The apparatus is one comprising a moistening blade having a discharge slot therein. Means are provided in the moistening blade to sense when an air pocket has formed therein. When this means senses the air pocket, a control is actuated to supply additional fluid to the blade to force the air pocket out of the system.

Description

United States Patent 1191 Lahore et al.

[451 Sept. 16, 1975 1 ENVELOPE FLAP MOISTENING APPARATUS [75] Inventors: Walter T. Lahore, Stamford;

Richard A. Hallenbeck, Wilton, both of Conn.

[73] Assignee: Pitney-Bowes, Inc., Stamford, Conn.

[22] Filed: Oct. 10, 1974 [21] Appl. No.: 513,526

[52] US. Cl. 118/7; 118/32; 118/401; 156/441.5 51 Int. c1. B05C 11 105 [58] Field of Search 118/7, 2, 32, 401, 410, 118/411; 156/441.5

[56] References Cited UNITED STATES PATENTS 1,894,427 l/1933 Ryan 118/401 1,987,813 1/1935 Allen 118/32 2,167,257 7/1939 Wheeler, Jr. 118/401 2,368,520 l/1945 Burckhardt et 31.... 1 18/401 2,369,314 2/1945 Ryan 118/40] 2,372,742 4/1945 Ryan 1 18/401 3,707,059 1/1973 Carr et al 118/7 3,810,779 5/1974 Pickett et a1 1 18/401 Primary Exam'irierMervin Stein Assistant Examiner-Douglas Salser Attorney, Agent, or FirmWilliam D. Soltow, Jr.; Albert W. Scribner; Robert S. Salzman [57] ABSTRACT A moistening apparatus for wetting the gummed surface of an envelope flap. The apparatus is one comprising a moistening blade having a discharge slot therein. Means are provided in the moistening blade to sense when an air pocket has formed therein. When this means senses the air pocket, a control is actuated to supply additional fluid to the blade to force the air pocket out of the system.

5 Claims, 5 Drawing Figures BBQ-5.325

PATENTEBSEP 161975 SHEET 1 [1F 2 Pmmggsmms 3,905,325

SEMI 2 OF 2 Fis. 4.

H'SVAC 1 ENVELOPE FLAP MOISTENING APPARATUS" P The invention is for an improved envelope flap moist- I ening apparatus of the blade discharge type as used generally in mailing machines, and more particularly for an envelope flap blade moistening apparatus having BACKGROUND OF THE INVENTION.

Heretofore, the use of blade-like moisteners having a capillary-like slot for wetting the gummed surface of an envelope flap were beset with a rather disturbing problem. If an air pocket would be caused to form in the moistening blade, the blade would cease to supply moistening fluid to any subsequent envelope flaps passing in contact with the blade slot. This often occurring condition required that the operator of the mailing machine incorporatingthe moistener had to be on constant guard to prevent a large volume of mail from being processed without being properly sealed. If the operator was not diligent, the letters'were either mailed without being sealed, or if discovered in time, would still require a time consuming rescaling operation.

Obviously then, there has been a need for preventing or eliminating the formation of air pockets in blade moisteners. The present invention is directed to this need.

SUMMARY or THE INVENTION This invention relates to blade-like moistening devices having a'capillary slot which wets the gummed surface of envelope flaps passing contiguously thereof. The blade rnoistener is supplied fluid by a reservoir, whose water level is maintained slightly below the slot of the moistening blade. Thereservoir and blade are connected by a conduit having a priming pump disposedtherein.

iEnvelope flaps passing contiguously of the blade will causewater to be continuously drawn from the reservoir-by capillaryaction. In those instances where an air pocket forms in the blade it is necessary toprime the blade. To this end, a pump is provided in the conduit to supply a priming charge of fluid to the moistening blade.

A solenoid attached to the plunger of the pump is actuated every time an air pocket is sensed, thus automatically supplying the prime. The sensing mechanism of the invention comprises a thermistor which is located in the well of the moistening blade. The thermistor forms part of a voltage divider circuit that controls the solenoid.

When the thermistor is surrounded by water, as when there is no air pocket in the supply line, the cooling effect of the surrounding liquid causes the thermistor to 2 It is another object of the invention to provide means for automatically sensing drynessand controlling the priming .of fluidsupply to a moistening blade;

have a high resistance. In this condition, the solenoid remains inactuated.

When an air-pocket forms in the supply line, the thermistor loo'ses'the cooling effects of the liquid, and is caused to immediatelyheat up. In so doing, the resistance of the thermistor is caused to drop, and the solenoid controlling the pump is actuated. Thus, the prim ing pump automatically supplies a priming-charge to the moistening blade every time an air pocket-forms.

It is an object of this invention to provide an improved moistening apparatus of the blade type;

ltis still another vobject of this invention to provide a means for sensing and controlling'the formation of air pockets in the moistening blade.

These and other objects of the invention will be be t ter understood and will become more apparent with reference to the following detailed description taken in conjunction with the 'attacheddrawings, in which:

FIG. 1 is a perspective -view 'of the envelope flap moistening blade apparatus of this. invention; v

FIG. 2 is an enlargedview of the moistening blade of FIG. 1, showing a cutaway-portion revealing a thermistor disposed in the fluid well of the blade; 7 I

FIG. 2A is a sectional view of the moistening blade of FIG. 2; taken along lines 2A-2A; v

FIG. 3 is a sectionalview of-the blade of FIG. 2, taken along lines 3-3; and y FIG. 4 is a circuit diagram of the sensing and control circuit of the invention shown in FIG. 1.

DETAILED DESCRIPTION Generally speaking, this-invention is for an envelope moistening fluid is connected to the blade via a,con-

duit.-The level of the fluid in the reservoir is generally maintained below the level of the discharge slot of the blade. Priming means comprising a pump is provided in the conduitfor supplying a quantity of moistening fluid to the blade, when the blade runs dry (loses.prime) Sensing means supported by'the blade senses this dry condition; Control means operatively connected between the sensing means and the priming means causes the pump to supply the moistening blade with fluid in response to. the sensing of dryness in said moistening blade by the sensing means.

Nowreferring to- FIG. 1, an envelope 9 having a flap 12' is shown disposed atop of a feeder deck 11. The envelope 9 is:guided along the feeder deck 11 by means of guide wall 10."The envelope 9 and its flap 12 move (arrow14') alongv the feeder deck .11 in a feed path which brings the flap 12 into contiguous engagement with a moistening-blade 15. The envelope flap 12 has a gummed surface 16 facing upwardly towards a slot 17 in the bottomof the moistening blade 15 (seeFIG.

2A). A spring guide 50 causes the gummed surface of flap 12 to come in contact with that slot 17. When the gummed portion 16 of the flap 12 passes contiguously of the slot 17, water '18 contained within the slot is drawn out of the slot onto the flap. The gummed portion 16 of the flap is thusly wetted.

' As' water. is extracted from blade 15 itis replenished by fluid'contained in reservoir'19 (FIG. 1). The fluid level 20' of reservoir 19 is maintained below the level of slot 17. This provides-a concave meniscus 21 (FIG. 2A) in the fluid 18 of the slot. The purpose of this arrangement provides that the water supplied to blade 15 will not continuously drip from the slot. Rather, the fluid will flow only when extracted'bythe surface tension created by the affinityo'f the contiguously passing envelope flap.

A conduit 22 connects the reservoir 19 with the blade as shown in FIG. 1. A priming pump 23 is connected into the line 22 between reservoir 19 and blade 15. The priming pump 23 is of the kind as can be found in mailing machine Model 5600, manufactured by Pitney-Bowes, lnc., Stamford, Connecticut, the present assignee of this invention.

A solenoid 24 is connected to the plunger 25 of the pump 23 via pivoted link 40. The solenoid 24 is controlled by a sensing and control circuit (FIG. 4) schematically depicted by block 26 of FIG. 1. Forming part of the sensing and control circuitry 26 is a thermistor 27, which is schematically shown connected to circuit 26 via line 28. The head of the thermistor element 27 is disposed within the fluid supply cavity 29 of the moistening blade 15 (see FIGS. 2, 2A and 3).

The fluid cavity 29 is achieved by making blade 15 hollow and sealing this hollow space with a top cover plate 30 as shown in FIGS. 1, 2, 2A and 3.

OPERATION OF THE INVENTION In normal operation, water or a similar moistening fluid, will fill cavity 29 of the moistening blade 15 by means of priming pump 23. As water is drawn off slot 17 onto flap 12, it is continuously replenished by the capillary action of the slot drawing liquid from reservoir 19 via conduit 22.

In the event that an air pocket forms (loss of prime) in cavity 29, resulting in there being no water in slot 17 to moisten the envelope flaps, thermistor 27 immediately heats up. Its electrical resistance decreases, which actuates solenoid 24 via sensing and control circuit 26. The actuation of solenoid 24 causes the priming pump to supply the cavity 29 with a quantity of fluid forcing the air pocket out of the system. The thermistor 27 once again being surrounded by water, will cool down. lts resistance will once again become high,and the solenoid 24 will be de-actuated via circuit 26.

Now referring to FlG. 4, the sensing and control circuit 26 is shown. Thermistor 27 forms part of this voltage divider circuit as shown, along with resistor 42. The circuit is powered from a standard source of AC. current (115 V) via transformer 31, which transforms the voltage to 24V in order to isolate this circuit from the main power line. Taking point 32 as a reference, when the thermistor 27 is surrounded by water and is of high resistance, the voltage at point 33 will be lower than the reference point 32 maintaining SCR 34 in the off state. When the thermistor 27 heats up as when air surrounds the thermistor, its resistance drops, and the voltage at point 33 will rise above the reference point 32. When this happens, SCR 34 will be in the on state and current will flow through solenoid 24 as shown by arrow 43. The SCR 34 acts to energize the solenoid 24 for as long a period of time as the thermistor resistance remains low. However, the pump 23 will be actuated by the pull of solenoid 24, thus furnishing water to surround the thermistor. This will cause the thermistor 27 to cool and the resistance to increase. A tension spring 35 (FIG. 1) acts to return the plunger 25, and hence the solenoid 24 to its original unenergized position.

A resistor 36 and a diode 37 are placed in circuit 26 to limit the gate current of the SCR 34 within specificational limits. The resistor 38 acts to limit the sensitivity of the SCR 34.

Indicator lamp 41 connected across the solenoid 24 provides a visual signal to the operator of dryness or failure to regain prime.

Of course many changes of an obvious nature may occur to those skilled in the art. e.g.. a relay may be used in place of the solenoid 24. This relay could be continually energized as long as the thermistor 27 was in air. The relay would be used to turn on a continuously acting pump, in order to restore the prime. Such a continuous system might be more desirable where a large air pocket is formed, requiring several pump eycles to replenish the fluid supply.

Also, the indicator 41 may be replaced by means to de-actuate the envelope feed mechanism, such that when the system runs dry, envelopes will be prevented from being fed to the moistener apparatus.

These and other changes which would be obvious to the skilled practitioner in this art are deemed to fall within the spirit and scope of the invention as presented by the appended claims.

What is claimed is:

1. An envelope flap moistening apparatus, comprising:

means defining an envelope flap feed path;

a moistening blade extending into the envelope flap feed path and having a discharge slot for dispensing moistening fluid to a gummed portion of a contiguously passing envelope flap;

a reservoir operatively connected to said blade and containing moistening fluid for said moistening blade, a level of said moistening fluid in said reservoir generally disposed below a level of the discharge slot in the moistening blade;

priming means operatively connected between said reservoir and said moistening blade for supplying a quantity of moistening fluid to said moistening blade, when said moistening blade runs dry;

sensing means supported by said moistening blade for sensing when the moistening blade runs dry; and

control means operatively connected between said sensing means and said priming means for causing said priming means to supply the moistening blade with fluid in response to the sensing of dryness in said moistening blade by said sensing means.

2. The envelope flap moistening apparatus of claim 1, wherein said sensing means comprises a thermistor disposed within the moistening fluid being supplied to said moistening blade, said thermistor changing resistance in response to a lack of fluid surrounding said thermistor, which resistance change causes the control means to operate said priming means to supply said moistening blade with fluid.

3. The envelope flap moistening apparatus of claim 2, wherein said priming means comprises a solenoid actuated pump for discharging a quantity of fluid to said moistening blade and wherein the control means comprises a voltage divider circuit operatively comprising said thermistor as an operative. element thereof.

4. The envelope flap moistening apparatus of claim 3, wherein the solenoid actuated pump is maintained in actuation by a SCR as long as the thermistor continues to sense a dryness in the moistening blade.

5. The envelope flap moistening apparatus of claim 3, wherein an indicator means is disposed in the voltage divider circuit to indicate when the moistening apparatus requires fluid.

Claims

1. An envelope flap moistening apparatus, comprising: means defining an envelope flap feed path; a moistening blade extending into the envelope flap feed path and having a discharge slot for dispensing moistening fluid to a gummed portion of a contiguously passing envelope flap; a reservoir operatively connected to said blade and containing moistening fluid for said moistening blade, a level of said moistening fluid in said reservoir generally disposed below a level of the discharge slot in the moistening blade; priming means operatively connected between said reservoir and said moistening blade for supplying a quantity of moistening fluid to said moistening blade, when said moistening blade runs dry; sensing means supported by said moistening blade for sensing when the moistening blade runs dry; and control means operatively connected between said sensing means and said priming means for causing said priming means to supply the moistening blade with fluid in response to the sensing of dryness in said moistening blade by said sensing means.

3. The envelope flap moistening apparatus of claim 2, wherein said priming means comprises a solenoid actuated pump for discharging a quantity of fluid to said moistening blade and wherein the control means comprises a voltage divider circuit operatively comprising said thermistor as an operative element thereof.