US3867860A

US3867860A - Device for cutting open letter envelopes

Info

Publication number: US3867860A
Application number: US404012A
Authority: US
Inventors: Werner Haug
Original assignee: Frama AG
Current assignee: Frama AG
Priority date: 1972-10-09
Filing date: 1973-10-05
Publication date: 1975-02-25
Anticipated expiration: 1992-02-25
Also published as: NL7313224A; GB1423243A; NL154160B; DE2320324C3; SE388813B; FR2201978B1; CH538942A; NO135460B; DE2320324A1; DE2320324B2; DK139774B; DK139774C; FR2201978A1; IT995553B; NO135460C

Abstract

A device for cutting open letter envelopes comprises a guideway which includes a support surface over which the letter envelopes are moved and a lateral surface along which they are guided. The support surface has a longitudinal slot extending substantially parallel to the lateral guide surface and an endless belt conveyor extends with its upper reach through the slot to engage the envelopes and to advance them along the support surfaces. A pair of opposed cooperable rotary cutter blades define a nip therebetween which is aligned with the support surface so that the envelopes are directed between the nip and are cut open as they are moved. The top one of the cutter blades is mounted so that the blade may be shifted laterally in order to vary the plane of cutting which it effects in cooperation with the lower counter-roller which is wider than the upper roller and which is driven by a driving motor. A pivotal sensor engages the envelopes which are fed by the conveyor and is moved in response to the thickness of the envelope or the variations of its thickness to cause a shifting of the upper roller blade in order to vary the cutting plane thereof in accordance with the letter which is being advanced.

Description

United States Patent 1 Hang g [451 Feb. 25, 1975 DEVICE FOR CUTTING OPEN LETTER ENVELOPES [75] Inventor: Werner Hang, Langnau, Switzerland [73] Assignee: Frama A.G., Luperswil, Switzerland [22] Filed: Oct. 5, I973 211 App]. No.: 404,012

[30] Foreign Application Priority Data Oct. 9, 1972 Switzerland 14749/72 [52] [1.8. CI 83/368, 83/499, 83/912 [51] Int. Cl B43m 7/00 [58] Field of Search 83/368, 912, 499

[56] References Cited UNITED STATES PATENTS 2,027,045 1/1936 Keiser 83/912 X Primary ExaminerJ. M. Meister Attorney, Agent, or FirmMcGlew and Tuttle [57] ABSTRACT A device for cutting open letter envelopes comprises a guideway which includes a support surface over which the letter envelopes are moved and a lateral surface along which they are guided. The support surface has a longitudinal slot extending substantially parallel to the lateral guide surface and an endless belt conveyor extends with its upper reach through the slot to engage the envelopes and to advance them along the support surfaces. A pair of opposed cooperable rotary cutter blades define a nip therebetween which is aligned with the support surface so that the envelopes are directed between the nip and are cut open as they are moved. The top one of the cutter blades is mounted so that the blade may be shifted laterally in order to vary the plane of cutting which it effects in cooperation with the lower counter-roller which is wider than the upper roller and which is driven by a driving motor. A pivotal sensor engages the envelopes which are fed by the conveyor and is moved in response to the thickness of the envelope or the variations of its thickness to cause a shifting of the upper roller blade in order to vary the cutting plane thereof in accordance with the letter which is being advanced.

12 Claims, 5 Drawing Figures PATENTEDFEB25 1% 3'. 867, 860

SHEET 2 OF 2 EQQ i 27 DEVICE FOR CUTTING OPEN LETTER ENVELOPES FIELD AND BACKGROUND OF THE INVENTION This invention relates in general to letter opening devices and, in particular, to a new and useful device for cutting open letter envelopes which includes means for feeding envelopes in succession between two cooperating cutting rollers and with means for sensing the thickness of the envelopes and shifting the cutting rollers accordingly for the purpose of varying the plane of cutting in accordance with the envelope being handled.

DESCRIPTION OF THE PRIOR ART In the known envelope opening devices, there is usually some means to permit adjustment of the device to accommodate letters of different thicknesses but this adjustment must be made manually by displacing a pressure disc engaged on a thread and moving it through a predetermined angle so that the pair of blades which effects the cutting are moved away from the lateral guide for the envelopes into a more distant plane. However, because the letters to be opened are usually of unequal thicknesses, such devices require a great deal of manual operation, or the letters must be processed in accordance with size and thickness in separate groups.

SUMMARY OF THE INVENTION In accordance with the present invention, the draw backs of the prior art are eliminated and there is provided an automatic device for feeding envelopes between the nip of cooperating rollers which are adjusted in accordance with the size of each envelope which is fed. The arrangement includes a sensing member which is mounted so as to engage each envelope which is being fed and which is connected to shift one of a pair of cooperative blades which engage the envelope to cut it open. The sensing member is moved in an amount comparable to the letter thickness and it is connected through a combined lever and disc member to shift the cutting blade axially and laterally in respect to the guide surface by an amount comparable to any change in thickness of the envelope being processed. The arrangement is such that the distance of one of the cutting rollers from the plane of the lateral guide wall is changed as a function of the displacement of the sensing member which is displaced in accordance with the thickness of each envelope which is fed.

Accordingly, it is an object of the invention to provide a device for cutting open letter envelopes which includes means for feeding letter envelopes in succession between the nip of cooperating rollers which includes at least one having means for shifting it axially to adjust its cutting plane position in respect to a guidewall for the envelopes and which also includes means for sensing each envelope as it is fed so that the cutting blade is shifted by an amount to ensure that the cutting plane is properly set for the particular thickness of the envelope being fed.

A further object of the invention is to provide a letter opening device which is simple in design, rugged in construction and economical to manufacture.

For an understanding of the principles of the invention, reference is made to the following description of a typical embodiment thereof as illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the Drawings: Q

FIG. 1 is a side elevational view of an envelope cutting device constructed in accordance with the invention;

FIG. 2 is a top plan view of the device shown in FIG.

FIG. 3 is a partial sectional view of the adjustable mounting for the non-driven upper cutting blade shown in FIG. 1;

FIG. 4 is a plan view of one of the adjustment members for varying the position of a cutting blade; and

FIG. 5 is a plan view of a combined lever disc blade positioning control member for shifting the position of the cutting blade.

GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings in particular, the invention embodied therein, comprises an envelope feeding and opening device in which a plurality of letters or envelopes are supplied from the lefthand side of the machine shown in FIG. 1 in the direction of the arrow 1 so that they ar either placed on or fed into the left portion of the guideway, generally designated 2.

In accordance with the invention, the guideway 2 includes a support surface 4 over which the envelopes are fed and which is substantially perpendicular to a guide surface 5 against which they bear as they are moved. The envelopes are moved or fed when they come into contact with a conveying belt 3 having an upper reach which projects through a slot 9 defined in the support surface 4 and extending longitudinally therealong substantially parallel to the guide wall 5. The envelopes may be fed manually or by means of a mechanism (not shown) for removing them from a stacking container. Generally speaking, it is preferable that the feeding surface or support surface 4 be slightly inclined downwardly toward the guide wall 5 so that the envelopes will slip on the feeding surface due to gravity and the edge will move into lateral engagement with the guide wall 5 and move along this wall during the action of the conveying belt 3.

In the embodiment indicated, the conveying belt comprises an endless circular cross-section member trained around two spaced apart pulleys 6, 7, which are mounted below the guideway 2. The righthand pulley 7 is driven by a motor having a shaft 16 with a small diameter pulley 17 which drives through a pulley belt 13, a larger diameter pulley 14 on a shaft 15. The pulley 7 is also connected on the shaft 15. The upper reach of endless conveyor 3 projects through slot 9 defined in the support 4. The envelopes are engaged frictionally by the endless belt 3 which protrudes slightly above the surface of support 4 so that belt 3 comes into contact with the envelopes and advances them by frictional engagement up to the end of the guideway.

A pair of cutting blades, including a lower cutting blade or counterblade 11, which is affixed to shaft 15 for rotation therewith, and an upper blade 10 which is of a narrower width than the blade 11 are arranged adjacent to and substantially parallel to the end guide 5 and they define a cutting plane 12 which may be shifted toward and away from the guide 5 in accordance with the width of the envelopes being handled. The shaft 15 which is driven from the motor 50 carries both the lower cutting blade 11 and a pulley 7 and it is mounted below fixed support 4 on the front side of housing wall 8. The

blades

10 and 11 operate in alignment with a longitudinally extending slot 19 of the support 4.

A circular cutout 18 is provided in the guide wall for the upper cutting blade 10. Lower cutting blade 11 protrudes into guide way 2 and its carrying shaft 15 is biased by a spring (not shown) in a direction to urge the lower cutting blade 11 upwardly into cooperative engagement with the upper cutting blade 10. The two blades are always superposed and cooperate with each other as a cutting tool.

In accordance with the invention, there is a separate drrive for upper blade which is not shown but which, for example, may comprise a separate drive motor with a belt or friction roller transmission connection or a connection by a belt off the shaft which drives the lower blade 11.

In accordance with a further feature of the invention, the upper blade 10 is mounted for axial adjustment in order to vary the position of the cutting plane 12 and this mechanism is indicated in detail in FIG. 3. The cutting blade 10 is secured to a casing block 20 which is rigidly fixed, for example, by being press-fitted to a shaft 21. Casing block 20 is made hollow on the side opposite to blade 10, and it encloses a thrust bearing 22 which includes a bearing disc 24 which applies against the inner surface of casing block 20 and another hearing disc 24 which may apply directly or as indicated, indirectly, through an intermediate disc 26 against a lever actuator disc which during the cutting operation is immobile.

Radial slide bearings

27 and 28 provide a mounting for the shaft 21 in a supporting block 29 and they are affixed to a back wall 30 of the housing which extends parallel to the guide wall 5. An extension sleeve 31 is also mounted in the block 29 and it has an external thread which is threaded to the opening provided in the backwall 30. An adjusting disc 32 is also threaded on the exterior of the sleeve 3l. The circumference of the adjusting disc 32 is provided with a plurality of notches 33 and a pawl 34 which is affixed to the back wall 30 engages in one of the notches so as to prevent the disc from an unintentional turning. The pawl is movable so as to permit it to become disengaged from the notches 33 when rotation of the disc 32 and adjustment of its axial position is desired. The adjustment of the disc 32 permits a basic adjustment of the cutting plane 12 relative to the lateral guide wall 5. This adjustment is effected by moving pawl 34 out of notch 33 and then turning disc 32 on threaded sleeve 31, for example, by an incremental amount which, as shown in FIG. 4, may be as small as a 45 turn. The disc 32 is then locked into position again by means of pawl 34. The axial displacement which results from the turning of the adjusting disc 32 is transferred by means of the thrust bearing 22 to the casing block 20 and thereby to cutting blade 10 so that the entire assembly, comprising the cutting blade 10, casing block 20 and shaft 21 is axially displaced in the

bearings

27 and 28. A back movement of this assembly from the new position is prevented by the resilient pressure of cutting blade 11 against the upper cutting blade 10.

In order to permit not only a basic adjustment of the cutting plane 12 by means of the adjusting disc 32, but also an automatic immediate adjustment to accommodate letters having irregular thicknesses, the invention includes a further means for effecting an automatic adjustment in accordance with the thickness of the envelope which is being passed through the device. The mechanism includes a lever actuator disc 25, as shown in FIG. 5, which is pivotally mounted between thrust bearing 22 and adjusting disc 32. The disc 25 includes a lever portion 25a and a rotary motion of this lever actuator disc 25 produced by a slight displacement of a channel-shaped sensing lever 35 from its zero position which is caused by the passage of a letter which is thicker than the previous letter, results in an axial pressure against the thrust bearing 22, and thereby, in a displacement of the cutting blade 10. Cam-like elevations in the form of balls 36 engage into flat flaring recesses 37 of adjusting disc 32. Recesses 37 are impressed in disc 25 and have substantially V-shape cross-sections. The flare-shaped surfaces of recesses 37 form, for example, an angle of 20 with the main surface of the disc. As soon as lever 25a of the disc 25 is slightly turned by the action of the sensor member 35 which rides on the letter passing over the belt 3, the cam balls 36 are displaced along the sloping surfaces of recesses 37, so that the disc 25 is moved away from the locked adjusting disc 32 in the direction of thrust bearing 22 so that cutting blade 10 is axially displaced to accommodate the letter of thicker proportions.

Sensing lever 01' sensor 35 is pivotally mounted adjacent its righthand end on pin 38, as shown in FIG. 1, which is rigidly fixed between

walls

30 and 5, as shown in FIG. 2. Pin 38 passes through the two

legs

39 and 40 of the channel-shaped sensor 35 and a cross-pin 41 is rigidly fixed to pin 38 and extends perpendicularly thereto so that it lays along and below the web portion 42 of sensing lever 35. A screw 43 is threaded through web portion 42 of sensor 35 above cross-pin 41 and the end of the screw applies against the cross-pin 41 so that upon turning of screw 43, the sensing lever 35 is displaced by a small angle and its zero position is thus adjusted.

As shown in FIG. 2, sensor 35 extends above a part of conveying belt 3 so that a letter or envelope advanced through the device passes below the sensor 35. The spacing of the legs of the channel-shaped sensor 35 and their location, are chosen so that the

legs

39 and 40 are positioned so that they are laterally spaced above belt 3. The zero position of sensor 3 is adjusted so that only a letter of considerable thickness would cause an automatic adjustment of the cutting plane 12 and a displacement of sensor 35 upwardly. Letters of smaller thicknesses are cut open in a plane which has been appropriately adjusted as the basic or zero position with respect to the lateral guide wall 5 and by turning and locking adjusting disc 32.

Sensing lever 35 is connected by means of a transverse pin 44 to the free end of the lever portion 250 of lever-actuated disc 25, as shown in FIG. 2. Transverse pin 44 extends through a slot (not shown) which is provided in lateral guide wall 5 and the pin engages into a longitudinal slot 46 of lever portion 250 of leveractuated disc 25. In order to permit a particularly effortless displacing of the sensing lever 35, and thereby an easy turning of the lever-actuated disc 25, a tension spring 47 is attached, in the present example, to the end of lever portion 25a and the other end of spring 47 is fixed to pin 50 which is secured to back wall 30. Spring 47 compensates for the weight of sensing lever 35 and may be adjusted so as to give the lever a small bias in the clockwise direction. This bias must be small enough so as not to cause a turning of the lever-actuated disc 25 and thereby, a displacement of the cutting plane 12.

While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understoood that the invention may be embodied otherwise without departing from such principles.

I claim:

1. A device for cutting open envelopes, comprising means defining a guideway for envelopes, a motor driven conveying mechanism provided along said guideway engageable with the envelopes for moving them along said guideway, a pair of cooperative cutting blades arranged in opposition along said guideway and defining a cutting plane, said cutting plane being adjustable in respect to a side of said guideway, said guideway serving to guide the envelope edges to be cut open so that they are moved between said cutting blades, a sensing member engageable with each letter moved by said conveying mechanism along said guidway, an adjustment mechanism for the pair of cutting blades for shifting at least one of said blades laterally and being connected to said sensing member and actuated by displacement of said sensing member by the transported envelope according to the thickness thereof to vary the position of said cutting blades so that the distance of the cutting plane is changed as a function of the sensing member displacement.

2. A device for cutting open envelopes, according to claim 1, wherein said sensing member comprises a lever member pivoted at its trailing end and having a forward end overlying said conveyor which is movable upwardly and downwardly, an upper cutting blade rotatable shaft affixed to said cutting blade and being mounted for axial displaceable movement and a control member connected to said shaft and connected to said lever member being responsive to movement of said lever member to shift said shaft axially whereby to vary the position of said cutting blade on said shaft in accordance with the thickness of the envelope which is moved over said conveyor belt.

3. A device for cutting open envelopes, according to claim 2, wherein said adjusting member comprises a disc surrounding said shaft and having a lever portion connected to said sensing member, an adjustment disc on said shaft being fixable in a fixed location axially, ball cam means disposed between said adjustment disc and said control disc having said lever arm portion, said control disc having at least one recess carrying said ball cam means with sloping surfaces extending from the recess upwardly to the surface of said disc, said ball cam means being shiftable up the surface of said disc when said lever portion is moved to rotate said disc whereby to shift said disc axially to shift said cutting blade thereby.

4. A device for cutting open letter envelopes, comprising a guideway having a support surface over which the letter envelopes are moved and a lateral surface along which they are guided, said support surface having a longitudinal slot extending substantially parallel to said lateral guide surface, a movable conveyor having an upper reach aligned with the slot and projecting above the support surface to engage envelopes thereon for moving them along said support surface, a pair of opposed cooperable rotary cutter blades having a nip therebetween aligned with said support so that the envelopes which are moved by said conveyor are directed therebetween as they are guided by said lateral guide surface, adjustment means connected to at least one of said rotary cutter blades for shifting said one of said rotary cutter blades laterally for varying the cutting plane thereof, the other of said rotary cutter blades being wide enough to remain in cooperative engagement with said upper rotary cutter blades while the one rotary cutter blade is adjusted to vary the cutting plane position in respect to said lateral guidle surface, and a sensor overlying said suport surface engageable with the envelopes movable therealong and connected to said adjustment means to cause shifting of said at least one of said rotary cutter blades for varying the cutting plane in accordance with the thickness of the envelope which is sensed.

5. A device for cutting open letter envelopes, according to claim 4, including a shaft rotatably supporting said one of said rotary cutter blades which is axially adjustable, bearing means supporting said shaft for axial displacement, a thrust bearing surrounding said shaft including a positioning member which is adapted to be fixed in position, an adjusting member spaced axially from said fixed member, cam means located between said adjusting member and said fixed member, said sensor including a sensing member connected to said adjusting member which is displaceable in accordance with the thickness of the envelopes being fed to rotate said adjusting member to shift said cam means so as to shift said adjusting member axially along with said one of said rotary cutter blades.

6. A device for cutting open letter envelopes, according to claim 4, wherein said fixed member comprises a disc mounted on said cutter blade shaft, said adjustment member comprises an actuation disc having a lever arm portion rotatably mounted around said shaft, said sensorcomprising a member overlying said guideway and engageable with the letters being passed therealong and being connected to said lever to rotate it with said disc portion and to cause said cam means to effect axial displacement thereof along with said rotary blade.

7. A device for cutting open letter envelopes, accord ing to claim 6, wherein said sens-or comprises a lever having a trailing end pivotally mounted above said guideway and having a forward end overlying said guideway and engageable with the envelopes movable thereon, an equalizing spring connected to said forward end and holding said forward end above said guideway, and a zero adjustment mechanism connected to said lever sensor for adjusting its zero position.

8. A device for cutting open letter envelopes, according to claim 6, wherein at least one of said fixed member discs and said adjusting member disc having said lever portion is provided with at least one recess on the side facing the other member having sloping surfaces extending outwardly from the recess toward the surface of said disc, said cam means comprising a ball arranged in the recess and bearing in the recess on the other associated adjacent disc, said ball being displaceable out of said recess to shift the members apart to vary the position of said blade.

9. A device for cutting open letter envelopes, according to claim 8, wherein said recesses have a V-shape cross-section.

10. A device for cutting open letter envelopes, according to claim 4, wherein said conveyor comprises a round cross-section endless belt, said sensor comprising a lever pivotally mounted adjacent one end over endless belt.

12. A device for cutting open letter envelopes, according to claim 4, including a separate drive shaft for each of said upper and lower rotary cutting blades,

each of which are driven.

Claims

4. A device for cutting open letter envelopes, comprising a guideway having a support surface over which the letter envelopes are moved and a lateral surface along which they are guided, said support surface having a longitudinal slot extending substantially parallel to said lateral guide surface, a movable conveyor having an upper reach aligned with the slot and projecting above the support surface to engage envelopes thereon for moving them along said support surface, a pair of opposed cooperable rotary cutter blades having a nip therebetween aligned with said support so that the envelopes which are moved by said conveyor are directed therebetween as they are guided by said lateral guide surface, adjustment means connected to at least one of said rotary cutter blades for shifting said one of said rotary cutter blades laterally for varying the cutting plane thereof, the other of said rotary cutter blades being wide enough to remain in cooperative engagement with said upper rotary cutter blades while the one rotary cutter blade is adjusted to vary the cutting plane position in respect to said lateral guide surface, and a sensor overlying said suport surface engageable with the envelopes movable therealong and connected to said adjustment means to cause shifting of said at least one of said rotary cutter blades for varying the cutting plane in accordance with the thickness of the envelope which is sensed.

6. A device for cutting open letter envelopes, according to claim 4, wherein said fixed member comprises a disc mounted on said cutter blade shaft, said adjustment member comprises an actuation disc having a lever arm portion rotatably mounted around said shaft, said sensor comprising a member overlying said guideway and engageable with the letters being passed therealong and being connected to said lever to rotate it with said disc portion and to cause said cam means to effect axial displacement thereof along with said rotary blade.

7. A device for cutting open letter envelopes, according to claim 6, wherein said sensor comprises a lever having a trailing end pivotally mounted above said guideway and having a forward end overlying said guideway and engageable with the envelopes movable thereon, an equalizing spring connected to said forward end and holding said forward end above said guideway, and a zero adjustment mechanism connected to said lever sensor for adjusting its zero position.

10. A device for cutting open letter envelopes, according to claim 4, wherein said conveyor comprises a round cross-section endless belt, said sensor comprising a lever pivotally mounted adjacent one end over said guideway and having an opposite end disposed to overlie said belt so that the advanced envelopes pass between the belt and the bottom of said sensing lever.

11. A device for cutting open letter envelopes, according to claim 10, wherein said lever is of channel-shape cross-section having spaced apart legs spaced by a width approximately equal to the diameter of said endless belt.

12. A device for cutting open letter envelopes, according to claim 4, including a separate drive shaft for each of said upper and lower rotary cutting blades, each of which are driven.