US3771448A - Apparatus for printing bags - Google Patents

Abstract

Apparatus, for printing information on a paper bag, featuring a mechanism for raising a printing arm after a bag is printed, pivoting the arm in an arc to another position, and then actuating the arm toward an ink pad so that the printing plate contacts the pad. The cycles of operation are preferably sequentially timed with the operation of a device for stripping one bag at a time from a stack of bags.

Description

United States Patent 1191 Thomson et al.

[ Nov. 13, 1973 [54] APPARATUS FOR PRINTING BAGS 3,635,154 1/1972 Gery et a1. 101/334 X 3,599,566 8/1971 Flsh 101/333 [75] Invent: Ely Thom; Clyde 3,216,352 11/1965 Schnackel 101/333 Sailors, Jr., both of Houston, Tex.

[73] Assign: 32: 3: r i s Company Primary Examiner-Edgar S. Burr Assistant ExaminerClifford D. Crowder [22] Filed: Dec. 11, 1972 Attorney-Jerry B. Peterson et a1.

[21] App]. No.: 314,042

Related U.S. Application Data ABSTRACT [62] Division of Ser. No. 154,529, June 18, 1971, Y

abando'wd- Apparatus, for printing information on a paper bag, featuring a mechanism for raising a printing arm after [52] U.S. Cl 101/334, 101/44, 271/131 a bag is printed, pivoting the arm in an arc to another [51] Int. Cl B411 17/00 position, and then actuating the arm toward an ink [58] Fleld of Search 101/3331 pad so that the printing plate contacts the pad. The 101/105 44 cycles of operation are preferably sequentially timed with the operation of a device for stripping one bag at [56] References a time from a stack of bags.

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sum 10F 21 EL) KNOX THOMSON CLYDE A. SAILORS JR. I NVENTORS BY M WM ATTORAE' Y ELY KNOX THOMSON CLYDE A. SAILORS JR.

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\EXHAUST TO BAG em INVENTORS Z Fig.7 BY /6 W7 APPARATUS FOR PRINTING BAGS This is a division of application Ser. No. 154,529, filed June 18, 1971, now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention is a method and apparatus for stripping one bag at a time from the bottom of a stack of empty paper bags and moving the stripped bag into position for a subsequent operation such as the printing of information on the bag. Also included may be apparatus, sequentially timed with operation of the stripper, for automatically printing information on the stripped bag. The stripper-printer combination may be integrated with a bag filling machines so that one empty bag is stripped and printed each time a bag is filled with product. Altemately, the combination may be operated as a self-contained unit which will automatically supply the momentary impulse for the beginning of a cycle.

This invention was developed primarily for use in the carbon black industry, in which for several years different grades of carbon black have been packaged in bags of different colors. This practice is known as colorcoding. In view of the recent development of many new grades of carbon black, the present system, in which each bag is printed by the bag manufacturer with the grade designation, is believed to have become obsolete. This invention was developed in order to provide a relatively simple and economical means of using one color for all bags and for printing the desired grade and other nomenclature on the bags immediately prior to the filling thereof. If desired, the printing may include the use of a set of color-coded inks, either as background or as the printing type. It will be apparent that the method and apparatus of this invention will be applicable to the packaging of products other than carbon black.

2. Description of the Prior Art So far as we know there is no prior art disclosing or similar to our method and apparatus for stripping bags from the bottom of a stack of empty bags.

OBJECTS OF THE INVENTION The objects and advantages of this invention are as follows:

1. An economical and convenient means to identify material packaged in paper bags with the proper nomenclature, with or without color-coding.

2. Bag inventories can be reduced by using the same properly sized bags for different grades of black or other material.

3. Only those bags actually filled will have identification and printing in the space provided.

4. An interchange of bag supplies between plants during an emergency shortage can be initiated.

5. Customers can receive shipments from any one of several plants with the assurance that the bags will be the same color and appearance and that they will have the proper markings appearing in the identical location on each bag.

6. Elimination of the need for printing presses at the plants.

7. Elimination of the possibility of using an improperly-marked bag.

8. Elimination of the possibility of printing the wrong quantity of bags for a given quantity of product.

9. Simplicity of manufacture and operation.

SUMMARY OF THE INVENTION One aspect of this invention is a method and apparatus for stripping one bag at a time from the bottom of a stack of empty paper bags and moving the stripped bag into position for a subsequent operation such as the printing of information or pictorial matter on the bag. The key element of the stripper is a pick-up member which engages the folded lip of the bottom bag and carries the bag forward into position for the subsequent operation. Another aspect of the invention is apparatus, sequentially timed with operation of the stripper, for automatically printing the stripped bag. The stripper-printer combination may be integrated with a bag filling machine so that one empty bag is stripped and printed each time a bag is filled with product. Alternately, the combination may be operated as a selfcontained unit which will automatically supply the momentary impulse for the beginning of a cycle.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation view of the entire combination of stripper and printer;

FIG. 2 is a partial plan view of the combination taken along lines 22 of FIG. 1;

FIG. 3 is an end elevation view of the combination, taken along the lines 3-3 of FIG. 1;

FIG. 4 is a sectional view of the bag pickup and including a bag, taken along section lines 4-4 of FIG. 2;

FIG. 5 is a fragmentary sectional view taken along section line 5-5 of FIG. 2;

FIG. 6 is a view taken along the line 6--6 of FIG. 5;

FIG. 7 is a schematic diagram of the electrical and pneumatic control circuits and associated switches, valves, and air cylinders.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The basic components and operation of the invention will first be described. Referring to FIGS. l-3, table I, supported by base frame 3, is divided by divider 5 into two general sections; namely, a bag-holding and stripping section generally shown at 7, and a bag printing section 8 on the other side of divider 5 and including printer 9. The bags are stacked in the bag-holding section 7, and when the operation is commenced, the bottom bag 11 is engaged (at the folded lip 11a) by bag pickup 13, and is moved to the bag printing section by movement of pickup 13, along slot 14 to the position shown in dotted lines of FIG. 2. When the bag reaches the printing position, printer 9 automatically prints the desired identification on the bag. By means of a switch and air cylinder, pickup 13 then returns to its rest position as shown in solid lines in FIG. 2.

Referring to FIGS. 1-6, the construction and operation of the stripper will now be described in somewhat greater detail.

In order that bags may be stripped from a rather large stack of bags without the weight preventing proper stripping, the table 1 is preferably inclined at an angle with respect to the horizontal so that part of the weight of the bags is resting on side panel 15. The preferred horizontal is shown in FIG. 3. We prefer to use an angle of about 45 although other angles ranging from horizontal up to about can be used.

The angle of the table, however, has a tendency to cause the bags to curl up the side of the side panel 15. In order to obviate this curling action of the bags on panel 15, we prefer to allow the end a of panel 15 to move inwardly against the bags once each cycle by means which will be described below with reference to the description of the electrical and pneumatic control assembly. Of course, this action of panel 15 could be initiated by purely mechanical means; for example, by a lever actuated by bracket 17.

Movable tubular bag weight 10 rides on the top of the bag pile to keep the bottom bag in proper position.

Bag stop 29 is adjustably secured to table 1 as shown.

The movement back and forth of bag pickup 13 is controlled by air cylinder 33 connected by means of pulleys 35 (FIG. 7) to cable 37. The air supply to cylinder 33 is controlled by micro switches 39 and 41.

Retainer 43 (FIG. 2) is desirably included in order to hold the bags in proper position during printing.

Retainers 45 are desirably included in order to prevent any bags other than the bottom bag from moving into the printing position.

Adjustable bag guide bars 47 are desirably included to aid in guiding the bag to its proper position.

Referring to FIG. 5, the apparatus preferably includes air pipe 49 for supplying a plurality of air jets through holes or slits 50 in the pipe divider 5. Exhaust air is supplied for this purpose four times each cycle in order to prevent the bags from sticking together and to take part of the weight off the bottom bag.

Referring now to FIGS. 1 and 3, the action of the printer 9 will now be described. The printer is mounted within cover plates 57, and the printer assembly is slideably supported (at 58) by printer mounting frame 59. Referring to FIG. 3, the position of the printer in one direction can be adjusted by turning lever 60 attached to threaded rod 62, after releasing the locking devices 64 by means of levers 66. The position of the printer in the other direction is preferably adjustable because frame 59 is slideable (at 59a) on angle member 68, after releasing locking devic: i 70 by means of levers 72.

The printing plate 61, containing thedesired identification or nomenclature, is pressed against the bag (not shown) on table 1 by means of downward movement of printing arm 63 actuated by air cylinder 65 through rod 67. Rod 67 is pivotally secured to tongue 69 as shown in FIG. 3. After the bag is printed, air cylinder 65 is actuated in the opposite direction, thereby raising the printing arm and pivoting the printing plate to the position shown at 61a in dotted lines in FIG. 3, and then to the position 61b against printing ink pad 71. The angle of such pivot is about I l0-l40 and preferably about l-l30. A printing arm mounting shaft 73 (hidden by spacers 73a in FIG. 1) is secured to cover plates 57 to prevent lateral movement of the arm. Proper movement of the printing arm so as to provide movement of the printing plate from position 61a to 61b is assured by the fact that the outer surface of the printing arm contacts bearing 75 affixed to a bearing mounting shaft (hidden by spacers 76), which in turn is secured to cover plate 57. Slot 78 is included to allow movement of arm 63.

The upper portion of printing arm 63 has a hole drilled down the center to accommodate a compression spring 77. With no pressure on air cylinder 65 and consequently no force on rod 67, the force of spring 77, the

spring being under some compression, forces the bottom of the slot 78 into registry with the shaft 73. For proper operation, the static compression of spring 77 must be set to overcome the combined weight of the arm 63 and the printing plate 61 to maintain the bottom of the slot 78 in registry with the shaft 73.

As force is applied to rod 67 by the piston in cylinder 65, the arm 63 is restrained between shaft 73 and bearing to impart a linear motion to rod 63 and printing plate 61, so that the type on printing plate 61 will move linearly against the bag or other piece to be printed, rather than in an arc which would cause smearing of the printing.

As the assembly moves downward, more compression is applied to spring 77.

Conversely, when force is applied in the reverse direction on rod 67 by the piston in cylinder 65 without the spring force applied to arm 63, the arm would tend to move in an arc, since the direction of force applied by rod 67 is tangential to the axial line of arm 63. Since the force applied by the spring is greater than the initial force applied by rod 67, the spring force prevails to move arm 63 in a linear direction away from the table 1 until the bottom of the slot 78 contacts shaft 73, at which time the force applied through rod 67 exceeds the force applied by the compression force of spring 77. Since rod 67 is tangential to the linear axis of arm 63, arm 63 pivots on shaft 73, and arm 63 again moves in an arc toward position 61a. Thus, the function of spring 77 is to exert a linear force upon printing arm 63 in a direction opposite to the forward motion of the arm. By forward motion, we mean motion toward table 1 or printing ink pad 71. Alternately, a tension spring could be mounted externally of arm 63 to accomplish the same results.

Printing plate 61 is secured to printing arm 63 by means of a screw (not shown), but proper alignment is assured by the use of dowel pins 79 passing through holes in the bottom end of the printing arm into contact with tension springs (not shown).

The necessary control components such as solenoids, air valves, switches, relays, and terminals are mounted to the inside of one of the cover plates 57.

The electrical and pneumatic controls will now be described.

In FIG. 7, the plug is composed of two parts; a male portion 100M and a female portion 100F which, when connected, have common electrical terminals .1000, 100b, 1000, and 100d. In operation, the terminal 100a of plug 100M is connected to one leg of an AC circuit through a conduit represented by a solid line and the terminal 100b of 100M is connected to the opposite leg of the AC circuit as represented by the dotdash line. Terminals 100d of plugs 100M and 100F are connected to ground.

In the present invention the mechanism can be operated in either of two modes, namely: (i) controlled by a separate machine (such as a bag-filling machine) having an electrical circuit that will provide a momentary impulse of electric current to start the operation, in which case terminal 1000 of plug 100 will be connected to the separate mechanism that supplies the electrical impulse, or (ii) it can be operated as a self-contained unit that will automatically supply the momentary impulse for the beginning of a cycle and will continuously cycle as long as electric power and air power are supplied to the machine.

The circuit breaker 102 is a three-position switch, center-off as shown. In FIG. 7, the electrical connections in the control side of the circuit are represented by solid lines; the common electric circuit is represented by dot-dash lines; and all air conduits are represented by double lines. The circuits are drawn to show the standby condition except that with air pressure applied rough through 114 and thence through line 116, the supporting means or bracket 17 will move to its leftmost position (to the left of the position shown in FIG. 7) to actuate the switch 41.

The first mode of operation described will be as specified in mode (i) above in which the present invention operates as a slave to a second electro-mechanical device which supplies the mutual electrical impulse to start the cycle. To ready the cirduit for operation, switch 102 is thrown to establish contact between points 102a and 102b, and between points 102e and 102d, of switch 102. With air applied at the air intake line 114 and with points 100a, 100b and 1000 of plug 100M connected to their proper electrical source, the machine is in a standby position with air applied through ports 112W and 112X of the four-way air valve 112 to control valve 87A (via line 116) and then to port 33a of cylinder 33; and air is also supplied through ports 110W and 1 10X of four-way valve 110 to control valve 87C (via line 118) and then to port 65a of cylinder 65. When an electrical impulse is applied through point 1000 of plug 100, an electrical connection is established through points 102a and 1021) of switch 102 to terminal 106-4 of terminal strip 106 and thence through points 41a and 41b of switch 41 through terminal 106-3 to point 104a of the solenoid 104a-b of relay 104, since point 104b is connected to the common leg 1030 of the AC circuit through terminal 106-6 and thence through points 390 and 39d of switch 39 and back through terminal 106-5 to the common leg 1010 of the electrical circuit through point 100b of plug 100. At the instant relay 104 is actuated, the off-delay timer 105 is also actuated, completing a circuit between point 105 a and 105k. When relay 104 deactuates, offdelay timer 105 remains actuated for a pre-set time period and then deactuates, breaking connection between points 1050 and 10512.

Simultaneously with actuation of relay 104, electrical current is applied to point 1040 of relay 104 by the jumper wire 104n, and thence, since the relay 104 is actuated, through points 1040 and 104d to terminal 106-7 of terminal strip 106 and thence to point 112a of the solenoid 112a-b in the four-way air valve 112. This circuit is completed through point 1l2b of the air valve 112 through terminal 106-8 and thence through the common leg 1010 to point 100b of plug 100.

When the solenoid 112a-b of the air valve 112 is actuated as indicated above; the air valve element 112V shifts position in the direction indicated by the arrow to connect port 112W to port 112Y and port 112X to port 1122. At this instant, the air inlet 114 is connected through ports 112W and 112Y through line 120, to control valve 873, then to port 33b of cylinder 33. This causes the piston 33p to move to the left as shown in FIG. 7, and being connected to cable 37, causes bracket 17 to move to the right carrying the bag pickup mechanism 13 shown in FIGS. 2 and 4 to the left or forward, to engage a bag. In addition air flows through line 121 to port 50a of cylinder 50 causing piston 50? to retract rod 51 which is affixed to the flexible side panel 15 (FIG. 1) of the bag bin. Air is then exhausted through port 50b, into line 122, into line 116, and through pipe 49.

When the bracket 17, FIG. 7, moves to the right sufficiently to deactuate the switch 41, the points 410 and 41d of switch 41 close, establishing a circuit from point a of plug 100 through terminal 106-9, through l02c and jumper wire 102m to point 102f, and by the jumper wire 102n to point 102d, and thence through point 102e to terminal 106-1 via wire 108C to 104f, 104h via jumper wire P, through point 104g, via jumper wire 0 to point 104a, to point 1040 via jumper wire n, and then to 104d of relay 104. From point 104d, this current is connected through terminal 106-7 to the solenoid 1 12a-b of air valve 112, maintaining this air valve in an actuated condition until bracket 17 moves all the way to the right (FIG. 7) and actuates switch 39 thereby breaking the contacts 39c and 39d of switch 39 which are in the common return circuit 1030 of solenoid 104a104b. This breaking of contacts 390 and 39d thus results in the relay 104 returning to its normal or deactuated condition, thereby closing points 104i and 104j, and points l04f and 1040, of relay 104. At this instant the following actions occur:

I. Solenoid 112a-b of air valve 112 is deactuated,

and by spring return the valve element 112V revolves clockwise, connection port 112X with port 112W and port 112Z with port 112Y. This results in air pressure being applied through line 114 through air valve 112 and line 116 to port 33a of cylinder 33 causing the piston 33P of cylinder 33 to move to the right as shown in FIG. 7. Also, air pressure is applied through line 122 to port 50b of cylinder 50 causing piston 50? to extend rod 51 which is affixed to the flexible end 15a of the bag bin. Air is then exhausted through port 50a into line 121 which connects to lines 120, 126, and 49.

2. A circuit is completed between point 100a, through terminal 106-9 through points 0, f (via jumper m), d (via jumper n), and e of switch 102, to terminal 106-1 and points 104f and 104e of relay 104. Thence the circuit is completed through points a and 105b of off delay timer 105, then to terminal 106-10, and point a of solenoid 110a-b of air valve 110. This circuit is completed from point 11% through terminals 106-11, and then back through the common leg 1010 to point 100b of plug 100.

3. When the solenoid 110a-b is actuated, the valve element 110V of air valve 110 rotates in the direction of the arrow to connect port 110W with port 110Y and port 110X with port 1102. This applies air pressure through ports 110W and 1 10Y and line 1 11 to control valve 87D and to the port 65b of cylinder 65 causing rod 67 to actuate printing plate 61 to print the bag positioned by bag pickup 13. Air is also exhausted through port 65a and lines 118 and 124 to pipe 49.

4. The piston 33p of cylinder 33 having moved all the way to the right with bracket 17 actuating switch 41, opening contact points 410 and 41d and closing points 41a and 41b. The points 105a and 105b of the off-delay timer 105 now open after concluding the pre-set delay period, breaking the circuit and deactuating solenoid 110a-b of air valve 110. By spring return the valve element 110v revolves clockwise, connecting port 110W with port 110X and port 1102 with port llY. This applies air pressure through ports 110W and 110X and line 118 to control valve 87C and to port 65a of cylinder 65 causing rod 67 to actuate and move printing plate 61 in position against ink pad 71 as shown in FIG. 3. Air is also exhausted through port 65b and lines 111, 124, and pipe 49.

The speeds of movement of the piston in the cylinders 33 and 65 are controlled by the flow control valves 87A, 87B, 87C and 87D. The flow control valves 87 are characterized in that through a ball-check arrangement there is free flow of air through the valve in the direction opposite the arrow and a variably restricted flow of air in the direction of the arrow. Since the ports 110Z and 1122 of the air valves 110 and 112 are connected to exhaust, by the restriction of air flow through the valves 87, the movement of the pistons in cylinders 33 and 65 can be controlled by controlling the speed with which the air is exhausted from the cylinders through lines 124 and 126. In this way, together with the electrical circuit, the action of the cylinders is synchronized. This provides a wide latitude in the speeds at which the mechanism can be operated, the speed with which bags can be stripped, and the periods of time that the printing plate 61 is in contact with the ink pad and with the bag to be printed.

Lines 124 and 126 are connected to pipe 49 for the purpose described previously.

The second mode of operation (ii) is fully automatic and is attained when point 100a of plug 100 is connected with the proper electrical voltages and when the switch 102 is manually closed to connect point l02b with point l02c and point l02e with point l02f. When point l02b is connected with point 102:: of switch 102, an electrical circuit is established between point 100a of plug 100 through terminal 106-9 through points 1020 and l02b and thence through terminal 106-4 through points 41a and 41b of switch 41 to terminal 106-3, to point 104a of relay 104, and thence through the solenoid 104a-b through the common leg 1030 as previously described. This actuates relay 104 and connects points 104C and 104d and points 104g and 104k. The operation of the circuit from this point forward is identical to that as previously described; however, each time bracket 17 (FIG. 7) returns to its leftmost position it reactivates the circuit enabling the machine to repeat the cycle without utilizing an outside momentary electrical impulse.

While we have thus described the preferred embodiments of the present invention, many variations will be suggested to those skilled in the art. The foregoing description and examples should therefore not be considered limitative; and all such variations and modifications as are in accord with the principles described are meant to fall within the scope of the appended claims.

We claim: 1

1. A printer comprising:

reciprocal rod actuating means pivotally fixed at a stationary point;

a rod attached at one end to said actuating means and pivotally attached at the other end to a tongue projecting from the side ofa printing arm, said tongue being located at a point intermediate of the ends of said printing arm;

said printing arm having a printing plate attached to one end thereof;

said rod and said printing arm being substantially aligned in one plane but being slightly out of parallel when viewed perpendicular to said plane when said rod is in its extended position, the angle between said rod and said arm being convergent in a direction toward said tongue;

said arm being pivotally secured to a fixed point intermediate said tongue and the opposite end of said arm;

said arm containing a longitudinal slot in which is located a fixed printing arm shaft, the axis of said shaft being perpendicular to said arm and parallel to the axis of pivot of both said rod actuating means and said tongue, said shaft being located at a point intermediate said tongue and the opposite end of said arm;

a bearing surface mounted on a fixed bearing mounting shaft, said bearing mounting shaft being parallel to said printing arm shaft and being positioned between said rod and said arm at a point intermediate said printing arm shaft and the end of said arm opposite the end on which said printing plate is affixed;

whereby said printing arm is pivotable from an extended position, at which said rod is in its extended position, to a partially retracted position, at a pivot angle of about 1lO-l40 from said extended position, in which said arm contacts said bearing surface, and whereby said arm is movable in a straight line along said bearing surface to a fully-retracted position; and

a printing ink pad in a fixed position, said position being located so that said printing plate contacts said pad when said arm reaches said fully-extended position.

2. The printer of claim 1 in which said pivot angle is about l30.

3. The printer of claim 1 in which the reciprocal rod actuating means is a pneumatic system responsive to an electrical control circuit.

4. The printer of claim 3 in which the pivot angle is about l20-l30.

S. The printer of claim 3 including a spring means for exerting a linear force upon the printing arm in a direction opposite to the forward motion of said arm.

6. The printer of claim 5 in which the pivot angle is about 120l30.

7. The printer of claim 5 in which said spring means is a spring mounted within a hole drilled down the center of said printing arm from the end of said arm opposite said printing plate to said printing arm shaft.

8. The printer of claim 7 in which the pivot angle is about 120130.

Claims (8)

1. A printer comprising: reciprocal rod actuating means pivotally fixed at a stationary point; a rod attached at one end to said actuating means and pivotally attached at the other end to a tongue projecting from the side of a printing arm, said tongue being located at a point intermediate of the ends of said printing arm; said printing arm having a printing plate attached to one end thereof; said rod and said printing arm being substantially aligned in one plane but being slightly out of parallel when viewed perpendicular to said plane when said rod is in its extended position, the angle between said rod and said arm being convergent in a direction toward said tongue; said arm being pivotally secured to a fixed point intermediate said tongue and the opposite end of said arm; said arm containing a longitudinal slot in which is located a fixed printing arm shaft, the axis of said shaft being perpendicular to said arm and parallel to the axis of pivot of both said rod actuating means and said tongue, said shaft being located at a point intermediate said tongue and the opposite end of said arm; a bearing surface mounted on a fixed bearing mounting shaft, said bearing mounting shaft being parallel to said printing arm shaft and being positioned between said rod and said arm at a point intermediate said printing arm shaft and the end of said arm opposite the end on which said printing plate is affixed; whereby said printing arm is pivotable from an extended position, at which said rod is in its extended position, to a partially retracted position, at a pivot angle of about 110*140* from said extended position, in which said arm contacts said bearing surface, and whereby said arm is movable in a straight line along said bearing surface to a fully-retracted position; and a printing ink pad in a fixed position, said position being located so that said printing plate contacts said pad when said arm reaches said fully-extended position.

2. The printer of claim 1 in which said pivot angle is about 120*-130*.

3. The printer of claim 1 in which the reciprocal rod actuating means is a pneumatic system responsive to an electrical control circuit.

4. The printer of claim 3 in which the pivot angle is about 120*-130*.

5. The printer of claim 3 including a spring means for exerting a linear force upon the printing arm in a direction opposite to the forward motion of said arm.

6. The printer of claim 5 in which the pivot angle is about 120*-130*.

7. The printer of claim 5 in which said spring means is a spring mounted within a hole drilled down the center of said printing arm from the end of said arm opposite said printing plate to said printing arm shaft.

8. The printer of claim 7 in which the pivot angle is about 120*-130*.

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