APPARATUS FOR INVERTING MAILING ENVELOPES
United States Patent 3838771
A housing is disclosed having upper and lower spaced pulleys at each end. A pair of endless belts are provided, with each belt being operatively connected between an upper pulley at one end and the lower pulley at the other end. The belts are each provided with a single twist between the ends thereof. A mailing envelope inserted between the pulleys at one end will be engaged by the belts which are being driven to thereby carry the envelope to the other end. The envelope is inverted as it is carried by the twisted belts.
US Patent References:
Machine for stacking paper cartons
Staude - April 1926 - 1580342
Cigarette turn around device
Parrish - March 1960 - 2929489
Sheet separating apparatus
Furr et al. - August 1962 - 3048393
Apparatus for making continuous strips of pastry, such as wafers
Thiele - November 1962 - 3064590
Tortilla machine
Vimenez et al. - December 1965 - 3223053
Machine for stacking paper cartons
Staude - April 1926 - 1580342
Cigarette turn around device
Parrish - March 1960 - 2929489
Sheet separating apparatus
Furr et al. - August 1962 - 3048393
Apparatus for making continuous strips of pastry, such as wafers
Thiele - November 1962 - 3064590
Tortilla machine
Vimenez et al. - December 1965 - 3223053
Application Number:
05/295231
Publication Date:
10/01/1974
Filing Date:
10/05/1972
View Patent Images:
Export Citation:
Primary Class:
Other Classes:
271/186
International Classes:
B65G47/248; B65G47/24; B65G15/14; B65G47/24
Field of Search:
198/33AC,165,238 271/34,35,185,186,198-203,2 425/370
US Patent References:
| 3738642 | SEPARATOR FOR NEW PAPER MONEY | June 1973 | Blaire |
Primary Examiner:
Schacher, Richard A.
Assistant Examiner:
Miller, James W.
Attorney, Agent or Firm:
Merchant, Gould, Smith & Edell
Claims:
What is claimed is
1. Apparatus for inverting mailing envelopes, comprising:
2. Apparatus for inverting mailing envelopes, comprising:
3. Article inverting apparatus, comprising:
1. Apparatus for inverting mailing envelopes, comprising:
2. Apparatus for inverting mailing envelopes, comprising:
3. Article inverting apparatus, comprising:
Description:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to the field of automatic mailing machines, and more particularly relates to the construction of a machine designed to invert mailing envelopes being discharged from a sealing machine to place them in the proper position to be accepted by a stamp affixing machine.
2. Description of the Prior Art
In recent years, machines have been developed to automatically stuff, seal and stamp envelopes for mailing. One system in common use employs a machine that automatically seals the envelope and then ejects the envelope in a generally horizontal plane with the sealed flap on top. The next step in the mailing procedure is to affix a stamp to the envelope. Another machine is available which will automatically affix the stamp. However, the envelope must be inverted so that the flap is down before it is inserted into the stamp machine. In the past, the envelopes have either been inverted manually or else somewhat complicated and unreliable mechanisms have been provided to accomplish this turn-over function. Typically, these inverting machines have been complicated all out of proportion to the difficulty of the task they are performing.
SUMMARY OF THE INVENTION
The present invention provides a simple, inexpensive, reliable and practically fool-proof device for inverting mailing envelopes. A pair of endless belts are mounted in a side-by-side relationship between two pairs of spaced pulleys. The pulleys are mounted in a common plane for rotation about parallel axes. Each belt is provided with a single twist by rotating one end thereof 180° with respect to the other end. The inside or center span of each belt is substantially in contact with the inside or center span of the other belt substantially throughout the common length thereof. The upper pulleys are driven in one direction while the lower pulleys are driven in the other direction so that the common center spans of the belts move in the same direction. An envelope inserted between the pulleys at one end will be engaged between the common spans of the two belts and carried thereby to the other end of the belts, and because the belts are twisted, will be inverted during the trip. In the preferred embodiment, the envelope engaging surfaces of the two belts are provided with correspondingly spaced, matching teeth to provide positive engagement between the common spans of the belts. The engagement depth is very shallow so as not to injure envelopes being carried therebetween.
The mailing envelope inverting apparatus of the present invention can be operated at relatively high speed so that an envelope inserted at one end will pass through the unit and be inverted in no more than a fraction of a second. The unit will accept envelopes as fast as they are discharged from the sealing machine and will eject them in a position suitable for acceptance by the samp affixing machine. Because of the simplicity, reliability and speed of operation of the present invention, the step of turning over the envelopes between the sealing and stamping stations is no longer a delay causing step in the mailing procedure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a typical envelope sealing machine and stamp affixing machine with an inverting device according to the present invention mounted therebetween, portions of the housing of the inverting device being broken away;
FIG. 2 is an enlarged fragmentary view in vertical section taken along line 2--2 of FIG. 1;
FIG. 3 is an enlarged fragmentary view in vertical section taken along line 3--3 of FIG. 1;
FIG. 4 is an enlarged view in vertical section taken along line 4--4 of FIG. 1, portions thereof being broken away;
FIG. 5 is an enlarged fragmentary plan view taken along line 5--5 of FIG. 2;
FIG. 6 is a greatly enlarged fragmentary sectional view taken along line 6--6 of FIG. 4 showing how the toothed belts engage;
FIG. 7 is a view similar to that of FIG. 2, showing a preferred embodiment of my invention;
FIG. 8 is a greatly enlarged fragmentary side view showing the relationship of the pulleys and belts at the entrance end of the preferred embodiment; and
FIG. 9 is a fragmentary view similar to that of FIG. 8 showing an envelope passing between the belts.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, wherein like reference numerals will be used throughout the several views to indicate like elements of the invention, there is disclosed in FIG. 1 a series of machines designed to seal, invert and stamp mailing envelopes. The envelope 10 passes through a flap sealing machine 11 and emerges from beneath a hold-down member 12 with the sealed flap facing upwardly. The envelope 10 passes through the sealing machine 11 in an end-to-end manner rather than sideways, so that one end of the envelope emerges from the sealing machine. The envelope emerging from the sealing machine 11 must be inverted before it is fed into the stamp machine 13 which applies an appropriate stamp to the upper right-hand corner of the face of the envelope 10. The first end of the envelope 10 to emerge from sealing machine 11 should also enter the stamp machine 13 first. However, the envelope must be turned over so that the flap faces downwardly. Machine 13 can be of the type shown in the co-pending U.S. patent application Ser. No. 157,374, filed June 28, 1971, and entitled "Postage Stamp Applicator." Of course, other types of stamp machines could be used as well.
The present invention relates to apparatus for inverting the mailing envelope 10 between its exit from the sealing machine 11 and its entry into the stamp machine 13. The embodiment of the invention shown in FIGS. 1-6 includes a rectangular, box-like housing 15 having parallel, spaced side walls 16, 17 and parallel, spaced end walls 18, 19. Housing 15 further includes a closed bottom 20 and a removable top 21. End wall 18 is provided with an envelope inlet opening 22 near the center thereof, of appropriate size to permit the envelope 10 to enter housing 15 therethrough. A similar envelope outlet opening 23 is formed in end wall 19. A pair of spaced guide members 24, 25 are mounted on opposite sides of the inlet opening 22, on the outside of the housing 15, facing toward the envelope emerging from sealing machine 11 and adapted to guide the envelope into the opening 22. The spacing of the guide members 24, 25 can be adjusted by means of a pair of adjustable locking nuts 24a, 25a which are threaded on studs extending from the end wall through appropriate slots 24b, 25b in the portions of the guide members which lie against the end wall 18.
Extending between the side walls 16, 17 adjacent the inlet opening 22 are a pair of parallel shafts 28 and 29. Shaft 28 is positioned directly above shaft 29. The two shafts are perpendicular to the side walls 16, 17. The ends of the shafts 28, 29 are rotatably mounted in individual bearing assemblies 30 which are bolted to the side walls.
A second pair of parallel shafts 31 and 32 extend between the side walls 16, 17 adjacent the envelope outlet opening 23. The shafts 31, 32 are again perpendicular to the side walls, with shaft 31 positioned directly above shaft 32. The ends of the shafts 31, 32 are also rotatably mounted in suitable bearing assemblies secured to the side walls. Although the bearing assemblies are shown to be fixedly mounted to the side walls, they could be adjustably mounted so that the shafts 28, 29 and 31, 32 could be moved farther apart to accommodate thicker envelopes.
Each of the four shafts has a pulley fixedly mounted at the center thereof. At the inlet end, a first or upper pulley 33 is mounted on shaft 28, and a second or lower pulley 34 is mounted on shaft 29. At the outlet end, a first or upper pulley 35 is mounted on shaft 31 and a second or lower pulley 36 is mounted on shaft 32. All four pulleys 33, 34, 35, 36 lie in a common plane extending perpendicular to the shafts.
A pair of flexible, endless timing-type belts 39, 40 are mounted on the pulleys. Belt 39 is mounted for operative engagement with first pulley 33 at the inlet end and second pulley 36 and the outlet end. Belt 40 operatively engages first pulley 35 at the outlet end and second pulley 34 at the inlet end. The belts 39, 40 each have a single twist between the ends thereof which is obtained by rotating one end of the belt 180° with respect to its other end. For the purpose of describing this relationship, each belt 39, 40 can be considered to have two spans extending between the pulleys at the ends thereof. Thus, belt 39 has an inner span 39a extending from the bottom of pulley 33 to the top of pulley 36, and an outer span 39b extending from the top of pulley 33 to the bottom of pulley 36. Belt 40 has an inner span 40a extending from the top of pulley 34 to the bottom of pulley 35 and an outer span 40b extending from the bottom of pulley 34 to the top of pulley 35. The term "inner" is used with respect to the inner spans 39a and 40a for two reasons. For one thing, the inner spans 39a, 40a run horizontally across the housing between the two sets of pulleys 33-34 and 35-36, and because at the center of the housing where the belts intersect halfway between the two pairs of pulleys, the inner spans 39a, 40a lie between the outer spans 39b, 40b.
Preferably, the belts 39, 40 are each provided with matching, engageable teeth 39c, 40c as best shown in FIG. 6. The belts 39, 40 have a smooth face which engages the pulleys. The faces of the belts having the teeth thereon thus face outwardly from the pulleys. The pulleys 33, 34 at the inlet end are spaced apart a predetermined distance such that an envelope inserted therebetween through the inlet opening 22 will be engaged by the belts 39, 40. As viewed in FIG. 2, the upper pulleys 33 and 35 are driven in a counterclockwise direction while the lower pulleys 34 and 36 are driven in a clockwise direction. The two inner spans 39a, 40a thus move together in the same direction, from left to right as shown in FIG. 2. Th inner spans 39a, 40a engage each other over the entire distance between the inlet pulleys 33-34 and the outlet pulleys 35-36. Thus, an envelope 10 inserted between them at the inlet end will be carried by the two inner spans 39a, 40a to the outlet end of the housing 15. Because of the previously described twist in the belts, the envelope will be inverted or flipped as it travels through the housing. Thus, the envelope 10 will be ejected from between the pulleys 35, 36 through the outlet opening 23 for engagement by apparatus on the stamp machine 13.
As shown in FIG. 6, the teeth on the belts preferably engage a very slight amount to help prevent slippage between the belts and to better engage the envelope 10 being carried therebetween. The depth of the engagement of the teeth is very short so as to prevent damage to the envelopes 10. In actual practice, this results in no damage to the envelopes 10 although a minor impression of the teeth can be seen on the envelopes 10.
To drive the pulleys 33-36, a separate drive pulley 43 is mounted on shaft 32 and is connected by means of a drive belt 44 to a drive pulley 45 on stamp machine 13. If desired, however, a separate drive motor could be provided within the housing 15. Drive pulley 43 causes rotation of drive shaft 32 and pulley 36 mounted thereon. Pulley 36 drives belt 39 which in turn drives pulley 33 and shaft 28. By virtue of the mating teeth on the two belts, belt 39 drives belt 40 at the same speed. In order to absolutely prevent slippage between the belts, I have also added a second drive belt 46 which operatively engages drive pulleys mounted on shafts 29 and 32 adjacent side wall 16. Belt 46 thus transfers drive power directly from driven shaft 32 to shaft 29. Because shaft 32 engages belt 39 and shaft 29 engages belt 40, both belts are driven at exactly the same speed so that no slippage between them can occur. Actually, the system will operate without difficulty under most conditions without belt 46 by virture of engagement between the teeth on the two belts. However, belt 46 does insure that no slippage between the belts will occur.
In the embodiments shown, the envelope engaging surfaces of the two belts are provided with matching teeth. However, if other means are provided to drive the two belts, it is only necessary that they move together at a common speed in a close relationship so as to frictionally engage an envelope between them. The frictional engagement must be sufficient to prevent slippage of the envelope with respect to the belt as it travels through the housing. In actual practice, the pulleys operate at a high rate of speed so that the envelope is carried through the housing 15 in a fraction of a second. The envelope 10 enters the housing 15 with the flap facing upwardly as shown in FIG. 1. As it enters the housing, it passes between the toothed belts on pulleys 33 and 34 and is engaged by the teeth on the inner spans 39a, 40a. The inner spans carry the envelope between them to the right as shown in FIG. 2 and because the belts have a single twist from one end to the other, the envelope is inverted as it is carried through the housing. It is thus ejected from between pulleys 35 and 36 with the flap facing downwardly.
In FIGS. 7-9, there is disclosed an improved and preferred embodiment of my invention. Because the structure is generally the same, except for the location of the pulleys, the same reference numerals will be used together with a prime notation. The basic difference between this preferred embodiment and the earlier described embodiment is that the shafts 28', 29' and 31', 32' are no longer vertically aligned. The two upper shafts 28' and 31' are mounted closer together than the two lower shafts 29' and 32'. The four shafts 28', 29', 31' and 32' are still parallel to each other, and the four pulleys 33', 34', 35' and 36' still lie in a common vertical plane. The upper shafts 28' and 31' have been moved an equal distance toward each other in a horizontal plane. Each has been moved inwardly a distance corresponding to about two-thirds or three-quarters of the diameter of the pulleys. Because the two top shafts 28' and 31' are moved toward each other an equal distance, the two belts 39' and 40' are still of equal length. The belts 39', 40' are mounted on the pulleys exactly as before and operate in the same manner to carry envelopes and invert them between the ends thereof.
As best shown in FIGS. 8 and 9, the result of moving the shafts out of vertical alignment is that the pulleys at each end are then spaced further apart. FIG. 8 shows the relationship of the two entrance pulleys 33', 34'. It will be noted from FIG. 8 that the two pulleys 33' and 34' are now spaced a considerable distance apart, as compared to the distance between the same pulleys in the other embodiment, as shown in FIG. 6. In the embodiment of FIGS. 1-6, the distance between the two pulleys at each end establishes a maximum thickness of envelope that can be carried therebetween. The embodiment of FIGS. 1-6 will basically accommodate one thickness of envelope. As opposed to this, the preferred embodiment shown in FIGS. 7-9 will accommodate a wide range of envelope thicknesses, without adjustment. As shown in FIG. 8, the belts under normal circumstances engage each other in the same manner as that previously described with reference to the other embodiment. However, in the event a much thicker envelope is being mailed, the belts 39', 40' of this embodiment can move apart as required to accommodate the thicker envelope, as shown in FIG. 9. The distance between the two pulleys 33', 34' is no longer the same limiting factor that it was in the other embodiment. The effective distance between the two pulleys 33', 34' is now A--A as shown in FIG. 9, rather than the distance B-B of the earlier embodiment. It should be emphasized that the distance between the inner spans 39a' and 40a' will automatically adjust to accommodate envelopes ranging in thickness from smaller than B--B up to A--A. Of course, to permit this accommodation, there must be at least a minimum amount of slack in the belts. However, I have observed that the belts can be relatively tight and still provide sufficient slack to accommodate the thicker envelopes.
The present invention thus provides a simple and effective means of inverting or flipping envelopes in an automated mailing system. The novel features of the present invention are defined in the following claims.
1. Field of the Invention
This invention relates generally to the field of automatic mailing machines, and more particularly relates to the construction of a machine designed to invert mailing envelopes being discharged from a sealing machine to place them in the proper position to be accepted by a stamp affixing machine.
2. Description of the Prior Art
In recent years, machines have been developed to automatically stuff, seal and stamp envelopes for mailing. One system in common use employs a machine that automatically seals the envelope and then ejects the envelope in a generally horizontal plane with the sealed flap on top. The next step in the mailing procedure is to affix a stamp to the envelope. Another machine is available which will automatically affix the stamp. However, the envelope must be inverted so that the flap is down before it is inserted into the stamp machine. In the past, the envelopes have either been inverted manually or else somewhat complicated and unreliable mechanisms have been provided to accomplish this turn-over function. Typically, these inverting machines have been complicated all out of proportion to the difficulty of the task they are performing.
SUMMARY OF THE INVENTION
The present invention provides a simple, inexpensive, reliable and practically fool-proof device for inverting mailing envelopes. A pair of endless belts are mounted in a side-by-side relationship between two pairs of spaced pulleys. The pulleys are mounted in a common plane for rotation about parallel axes. Each belt is provided with a single twist by rotating one end thereof 180° with respect to the other end. The inside or center span of each belt is substantially in contact with the inside or center span of the other belt substantially throughout the common length thereof. The upper pulleys are driven in one direction while the lower pulleys are driven in the other direction so that the common center spans of the belts move in the same direction. An envelope inserted between the pulleys at one end will be engaged between the common spans of the two belts and carried thereby to the other end of the belts, and because the belts are twisted, will be inverted during the trip. In the preferred embodiment, the envelope engaging surfaces of the two belts are provided with correspondingly spaced, matching teeth to provide positive engagement between the common spans of the belts. The engagement depth is very shallow so as not to injure envelopes being carried therebetween.
The mailing envelope inverting apparatus of the present invention can be operated at relatively high speed so that an envelope inserted at one end will pass through the unit and be inverted in no more than a fraction of a second. The unit will accept envelopes as fast as they are discharged from the sealing machine and will eject them in a position suitable for acceptance by the samp affixing machine. Because of the simplicity, reliability and speed of operation of the present invention, the step of turning over the envelopes between the sealing and stamping stations is no longer a delay causing step in the mailing procedure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a typical envelope sealing machine and stamp affixing machine with an inverting device according to the present invention mounted therebetween, portions of the housing of the inverting device being broken away;
FIG. 2 is an enlarged fragmentary view in vertical section taken along line 2--2 of FIG. 1;
FIG. 3 is an enlarged fragmentary view in vertical section taken along line 3--3 of FIG. 1;
FIG. 4 is an enlarged view in vertical section taken along line 4--4 of FIG. 1, portions thereof being broken away;
FIG. 5 is an enlarged fragmentary plan view taken along line 5--5 of FIG. 2;
FIG. 6 is a greatly enlarged fragmentary sectional view taken along line 6--6 of FIG. 4 showing how the toothed belts engage;
FIG. 7 is a view similar to that of FIG. 2, showing a preferred embodiment of my invention;
FIG. 8 is a greatly enlarged fragmentary side view showing the relationship of the pulleys and belts at the entrance end of the preferred embodiment; and
FIG. 9 is a fragmentary view similar to that of FIG. 8 showing an envelope passing between the belts.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, wherein like reference numerals will be used throughout the several views to indicate like elements of the invention, there is disclosed in FIG. 1 a series of machines designed to seal, invert and stamp mailing envelopes. The envelope 10 passes through a flap sealing machine 11 and emerges from beneath a hold-down member 12 with the sealed flap facing upwardly. The envelope 10 passes through the sealing machine 11 in an end-to-end manner rather than sideways, so that one end of the envelope emerges from the sealing machine. The envelope emerging from the sealing machine 11 must be inverted before it is fed into the stamp machine 13 which applies an appropriate stamp to the upper right-hand corner of the face of the envelope 10. The first end of the envelope 10 to emerge from sealing machine 11 should also enter the stamp machine 13 first. However, the envelope must be turned over so that the flap faces downwardly. Machine 13 can be of the type shown in the co-pending U.S. patent application Ser. No. 157,374, filed June 28, 1971, and entitled "Postage Stamp Applicator." Of course, other types of stamp machines could be used as well.
The present invention relates to apparatus for inverting the mailing envelope 10 between its exit from the sealing machine 11 and its entry into the stamp machine 13. The embodiment of the invention shown in FIGS. 1-6 includes a rectangular, box-like housing 15 having parallel, spaced side walls 16, 17 and parallel, spaced end walls 18, 19. Housing 15 further includes a closed bottom 20 and a removable top 21. End wall 18 is provided with an envelope inlet opening 22 near the center thereof, of appropriate size to permit the envelope 10 to enter housing 15 therethrough. A similar envelope outlet opening 23 is formed in end wall 19. A pair of spaced guide members 24, 25 are mounted on opposite sides of the inlet opening 22, on the outside of the housing 15, facing toward the envelope emerging from sealing machine 11 and adapted to guide the envelope into the opening 22. The spacing of the guide members 24, 25 can be adjusted by means of a pair of adjustable locking nuts 24a, 25a which are threaded on studs extending from the end wall through appropriate slots 24b, 25b in the portions of the guide members which lie against the end wall 18.
Extending between the side walls 16, 17 adjacent the inlet opening 22 are a pair of parallel shafts 28 and 29. Shaft 28 is positioned directly above shaft 29. The two shafts are perpendicular to the side walls 16, 17. The ends of the shafts 28, 29 are rotatably mounted in individual bearing assemblies 30 which are bolted to the side walls.
A second pair of parallel shafts 31 and 32 extend between the side walls 16, 17 adjacent the envelope outlet opening 23. The shafts 31, 32 are again perpendicular to the side walls, with shaft 31 positioned directly above shaft 32. The ends of the shafts 31, 32 are also rotatably mounted in suitable bearing assemblies secured to the side walls. Although the bearing assemblies are shown to be fixedly mounted to the side walls, they could be adjustably mounted so that the shafts 28, 29 and 31, 32 could be moved farther apart to accommodate thicker envelopes.
Each of the four shafts has a pulley fixedly mounted at the center thereof. At the inlet end, a first or upper pulley 33 is mounted on shaft 28, and a second or lower pulley 34 is mounted on shaft 29. At the outlet end, a first or upper pulley 35 is mounted on shaft 31 and a second or lower pulley 36 is mounted on shaft 32. All four pulleys 33, 34, 35, 36 lie in a common plane extending perpendicular to the shafts.
A pair of flexible, endless timing-type belts 39, 40 are mounted on the pulleys. Belt 39 is mounted for operative engagement with first pulley 33 at the inlet end and second pulley 36 and the outlet end. Belt 40 operatively engages first pulley 35 at the outlet end and second pulley 34 at the inlet end. The belts 39, 40 each have a single twist between the ends thereof which is obtained by rotating one end of the belt 180° with respect to its other end. For the purpose of describing this relationship, each belt 39, 40 can be considered to have two spans extending between the pulleys at the ends thereof. Thus, belt 39 has an inner span 39a extending from the bottom of pulley 33 to the top of pulley 36, and an outer span 39b extending from the top of pulley 33 to the bottom of pulley 36. Belt 40 has an inner span 40a extending from the top of pulley 34 to the bottom of pulley 35 and an outer span 40b extending from the bottom of pulley 34 to the top of pulley 35. The term "inner" is used with respect to the inner spans 39a and 40a for two reasons. For one thing, the inner spans 39a, 40a run horizontally across the housing between the two sets of pulleys 33-34 and 35-36, and because at the center of the housing where the belts intersect halfway between the two pairs of pulleys, the inner spans 39a, 40a lie between the outer spans 39b, 40b.
Preferably, the belts 39, 40 are each provided with matching, engageable teeth 39c, 40c as best shown in FIG. 6. The belts 39, 40 have a smooth face which engages the pulleys. The faces of the belts having the teeth thereon thus face outwardly from the pulleys. The pulleys 33, 34 at the inlet end are spaced apart a predetermined distance such that an envelope inserted therebetween through the inlet opening 22 will be engaged by the belts 39, 40. As viewed in FIG. 2, the upper pulleys 33 and 35 are driven in a counterclockwise direction while the lower pulleys 34 and 36 are driven in a clockwise direction. The two inner spans 39a, 40a thus move together in the same direction, from left to right as shown in FIG. 2. Th inner spans 39a, 40a engage each other over the entire distance between the inlet pulleys 33-34 and the outlet pulleys 35-36. Thus, an envelope 10 inserted between them at the inlet end will be carried by the two inner spans 39a, 40a to the outlet end of the housing 15. Because of the previously described twist in the belts, the envelope will be inverted or flipped as it travels through the housing. Thus, the envelope 10 will be ejected from between the pulleys 35, 36 through the outlet opening 23 for engagement by apparatus on the stamp machine 13.
As shown in FIG. 6, the teeth on the belts preferably engage a very slight amount to help prevent slippage between the belts and to better engage the envelope 10 being carried therebetween. The depth of the engagement of the teeth is very short so as to prevent damage to the envelopes 10. In actual practice, this results in no damage to the envelopes 10 although a minor impression of the teeth can be seen on the envelopes 10.
To drive the pulleys 33-36, a separate drive pulley 43 is mounted on shaft 32 and is connected by means of a drive belt 44 to a drive pulley 45 on stamp machine 13. If desired, however, a separate drive motor could be provided within the housing 15. Drive pulley 43 causes rotation of drive shaft 32 and pulley 36 mounted thereon. Pulley 36 drives belt 39 which in turn drives pulley 33 and shaft 28. By virtue of the mating teeth on the two belts, belt 39 drives belt 40 at the same speed. In order to absolutely prevent slippage between the belts, I have also added a second drive belt 46 which operatively engages drive pulleys mounted on shafts 29 and 32 adjacent side wall 16. Belt 46 thus transfers drive power directly from driven shaft 32 to shaft 29. Because shaft 32 engages belt 39 and shaft 29 engages belt 40, both belts are driven at exactly the same speed so that no slippage between them can occur. Actually, the system will operate without difficulty under most conditions without belt 46 by virture of engagement between the teeth on the two belts. However, belt 46 does insure that no slippage between the belts will occur.
In the embodiments shown, the envelope engaging surfaces of the two belts are provided with matching teeth. However, if other means are provided to drive the two belts, it is only necessary that they move together at a common speed in a close relationship so as to frictionally engage an envelope between them. The frictional engagement must be sufficient to prevent slippage of the envelope with respect to the belt as it travels through the housing. In actual practice, the pulleys operate at a high rate of speed so that the envelope is carried through the housing 15 in a fraction of a second. The envelope 10 enters the housing 15 with the flap facing upwardly as shown in FIG. 1. As it enters the housing, it passes between the toothed belts on pulleys 33 and 34 and is engaged by the teeth on the inner spans 39a, 40a. The inner spans carry the envelope between them to the right as shown in FIG. 2 and because the belts have a single twist from one end to the other, the envelope is inverted as it is carried through the housing. It is thus ejected from between pulleys 35 and 36 with the flap facing downwardly.
In FIGS. 7-9, there is disclosed an improved and preferred embodiment of my invention. Because the structure is generally the same, except for the location of the pulleys, the same reference numerals will be used together with a prime notation. The basic difference between this preferred embodiment and the earlier described embodiment is that the shafts 28', 29' and 31', 32' are no longer vertically aligned. The two upper shafts 28' and 31' are mounted closer together than the two lower shafts 29' and 32'. The four shafts 28', 29', 31' and 32' are still parallel to each other, and the four pulleys 33', 34', 35' and 36' still lie in a common vertical plane. The upper shafts 28' and 31' have been moved an equal distance toward each other in a horizontal plane. Each has been moved inwardly a distance corresponding to about two-thirds or three-quarters of the diameter of the pulleys. Because the two top shafts 28' and 31' are moved toward each other an equal distance, the two belts 39' and 40' are still of equal length. The belts 39', 40' are mounted on the pulleys exactly as before and operate in the same manner to carry envelopes and invert them between the ends thereof.
As best shown in FIGS. 8 and 9, the result of moving the shafts out of vertical alignment is that the pulleys at each end are then spaced further apart. FIG. 8 shows the relationship of the two entrance pulleys 33', 34'. It will be noted from FIG. 8 that the two pulleys 33' and 34' are now spaced a considerable distance apart, as compared to the distance between the same pulleys in the other embodiment, as shown in FIG. 6. In the embodiment of FIGS. 1-6, the distance between the two pulleys at each end establishes a maximum thickness of envelope that can be carried therebetween. The embodiment of FIGS. 1-6 will basically accommodate one thickness of envelope. As opposed to this, the preferred embodiment shown in FIGS. 7-9 will accommodate a wide range of envelope thicknesses, without adjustment. As shown in FIG. 8, the belts under normal circumstances engage each other in the same manner as that previously described with reference to the other embodiment. However, in the event a much thicker envelope is being mailed, the belts 39', 40' of this embodiment can move apart as required to accommodate the thicker envelope, as shown in FIG. 9. The distance between the two pulleys 33', 34' is no longer the same limiting factor that it was in the other embodiment. The effective distance between the two pulleys 33', 34' is now A--A as shown in FIG. 9, rather than the distance B-B of the earlier embodiment. It should be emphasized that the distance between the inner spans 39a' and 40a' will automatically adjust to accommodate envelopes ranging in thickness from smaller than B--B up to A--A. Of course, to permit this accommodation, there must be at least a minimum amount of slack in the belts. However, I have observed that the belts can be relatively tight and still provide sufficient slack to accommodate the thicker envelopes.
The present invention thus provides a simple and effective means of inverting or flipping envelopes in an automated mailing system. The novel features of the present invention are defined in the following claims.