Box sheet bending apparatus

An apparatus for bending a box sheet along a fold formed at a predetermined position in the box sheet comprising a hook which can hang a tip of the sending box sheet, a sensor which can detect said tip of the sending box sheet, and a lifting means which can lift a part between said tip and a first fold of the sending box sheet up, wherein a tip of said hook is positioned above a sending route of the box sheet, and wherein, when said sensor detects said tip of the sending box sheet, said lift means can lift said part between the tip and the first fold of the sending box sheet up to said position of said hook.

BACKGROUND OF THE INVENTION
 1. Field of the Invention
 The present invention relates to the field of box-making machines,
 Specifically, the present invention provides an apparatus for bending a
 sending box sheet or a sending box sheet blank along a fold formed at a
 predetermined position in the box sheet.
 2. Description of the Related Art
 Conventionally, an apparatus for bending a sending box sheet along a fold
 formed at a predetermined position in the box sheet comprises a hook,
 which can hang a tip of the sending box sheet, and a sensor which can
 detect said tip of the sending box sheet. Accordingly, said sensor can
 detect said tip of the sending box sheet, and said hook can bend the
 sending box sheet along a first fold by holding a tip of the sending box
 sheet.
 Namely, as shown in FIG. 8(a), in a typical device for bending a sending
 box sheet along a fold, a hook 5 is provided. The hook 5 is pressed by a
 spring for an opposite direction (left direction of FIG. 8(a)) of a
 sending direction of a box sheet 1 and can move the sending direction
 (right direction of FIG. 8 (a)) of the box sheet 1. A tip 5a of the hook 5
 is positioned on a sending route of the box sheet. Therefore, when the box
 sheet 1 is sent, the tip 5a of the hook 5 holds the tip 1a of the sending
 box sheet 1.
 When the box sheet is further sent, the hook 5 moves in the sending
 direction of the sending box sheet 1. Then, as shown in FIG. 8(b), the box
 sheet I is bent along a first fold by a force of the spring. The box sheet
 is further sent, as shown in FIG. 8(c), and because the tip 5a of the hook
 5 is left of the tip 1a of the box sheet 1, the hook 5 is restored by
 force of the restitution of the spring, and then the bending box sheet 1
 is sent frontwards.
 The typical device for bending a sending box sheet along a fold being thus
 described, it is possible to bend the box sheet automatically during the
 process of sending the box sheet. However, because the tip of the hook is
 on a sending route of the box sheet, when the hook is restored, the tip of
 the hook hits on a face of the sending box sheet, thereby making a noise.
 In cases where the box sheet is sent at high speed, the noise increases.
 Furthermore, certain countries regulate the importation of a device which
 makes noise beyond a prescribed level.
 SUMMARY OF THE INVENTION
 An objection of the present invention is to overcome the above-described
 problems and to provide an apparatus for bending a box sheet along a fold
 formed at a predetermined position in the box sheet comprising: a hook
 which can hang a tip of the sending box sheet; a sensor which can detect
 said tip of the sending box sheet; and a lifting means which can lift a
 part between said tip and a first fold of the sending box sheet; wherein a
 tip of said hook is positioned above a sending route of the box sheet; and
 wherein said sensor detects said tip of the sending box sheet, and said
 lift means can lift said part between the tip and the most fore fold of
 the sending box sheet up to said position of said hook.
 According to the present invention, given that the tip of the hook is
 positioned above a sending route of the box sheet, when the hook is
 restored, the tip of the hook does not hit on the face of the sending box
 sheet, and therefore a noise is not made.

DETAILED DESCRIPTION OF THE INVENTION
 Preferred embodiments of the present invention are described below in
 detail with reference to the accompanying drawings.
 FIGS. 1 and 2 show an apparatus for bending a box sheet according to the
 present invention.
 It is the apparatus for automatically bending a box sheet 1 along a fold 2
 formed at a predetermined position in the box sheet 1. The apparatus for
 bending a box sheet comprises two pairs of belts 3, 4 which can send the
 box sheet 1, a pair of hooks 5, a sensor 6 which can detect a tip 1a of
 the sending box sheet 1, and a lifting arm 7 which can lift a part 1b
 between the tip 1a and a first fold 2 of the sending box sheet up.
 Hook 5 is provided and is pressed by a spring (not pictured) from an
 opposite direction (left direction of FIGS. 1 and 2) of the sending
 direction of the box sheet 1 and for moving the sending direction (right
 direction of FIGS. 1 and 2) of the box sheet 1. A tip 5a of the hook 5 is
 bent for the opposite direction of the sending direction of the box sheet
 1 and therefore can hold the tip 1a of the sending box sheet 1. As shown
 in FIG. 1, the tip 5a of the hook 5 is positioned above a sending route of
 the box sheet 1, which is sending between belts 3 and 4.
 The lifting arm 7 comprises a pair of arms shaped in a letter of "L". Each
 of the arms is combined back to back. The lifting arm 7 can rotate so as
 to move the tip 7a of the lifting arm 7 at same speed and direction as the
 sending box sheet 1, when the tip 7a of the lifting arm 7 is positioned at
 the most upper part. As shown in FIG. 3, the lifting arm 7 is set up below
 the belts 3, 4 so as to lift the part 1b between the tip 1a and a first
 fold 2 of the sending box sheet at the time when each tip 7a is nearly
 positioned at the most upper part. As shown in FIG. 7, the lifting arm 7
 is connected to a controlled device, 8, which can control the lifting arm
 7.
 The sensor 6 is provided so as to be above the belts 3, 4 and to be in the
 same position as the lowest reaches of the tip 7a of the lifting arm 7. As
 shown in FIG. 6, the sensor 6 is connected to the controlled device 8.
 When the sensor 6 detects the tip 1a of the sending box sheet 1, the
 sensor 6 sends an information concerning the detection of the tip 1a of
 the sending sheet 1 to the controlled device 8. When the controlled device
 8 receives the information, the controlled device 8 makes the lifting arm
 7 rotate from a horizontal position of the lifting arm 7.
 A roller 9, a brush 10 and a guided rail 11 are provided above the belts 3,
 4 and at the upper reaches of the hook 5. A space between the belt 3 and
 roller 9, brush 10 and a guided rail 11, is shorter than the part 1b
 between the tip 1a and a first fold 2 of the sending box sheet. Therefore,
 the box sheet 1 is sent with bending by passing through this roller 9,
 brush 10 and guided rail 11.
 Next. an operation of the apparatus for bending the sending box sheet
 according to the present embodiment is described. First, the box sheet 1
 is sent one after another by operating the belts 3, 4. When the tip 1a of
 the box sheet 1 is passed through the sensor 6, the sensor 6 detects the
 tip 1a of the box sheet 1, and then sends the information concerning the
 detection of the tip 1a of the sending sheet 1 to the controlled device 8.
 When the controlled device 8 accepts the information, the lifting arm 7
 begins to rotate. When the lifting arm 7 begins to rotate, as shown in
 FIG. 3, a back face of the part 1b between the tip 1a and a first fold 2
 of the sending box sheet is pressed by the tip 7a of the lifting arm 7,
 and then, the box sheet 1 is bent along the fold 2 until the tip 1a of the
 box sheet 1 reaches the height of the tip 5a of the hook 5. In this time,
 because the tip 7a of the lifting arm 7 is rotating at the same direction
 and speed as the sending box sheet 1, when the lifting arm 7 presses the
 back face of the box sheet 1, almost no noise is made.
 When the box sheet 1 is further sent, as shown in FIG. 4, the tip 1a of the
 box sheet 1 is held by the tip 5a of the hook 5. When the box sheet 1 is
 further sent, the hook 5 moves at the sending direction of the box sheet
 1. And, when the box sheet 1 is further sent, as shown in FIG. 5, the box
 sheet 1 is bent along the fold 2. When the box sheet 1 is further sent as
 shown in FIG. 6, the tip 5a of the hook 5 is left of the tip 1a of the box
 sheet 1, and the hook 5 is restored by a restitution force of the spring.
 Then, the bending box sheet 1 is sent to the roller 9, brush 10 and guided
 rail 11.
 In this time, as shown in FIG. 6, the hook 5 left from the tip 1a of the
 box sheet 1 is restored, but because the tip 5a is positioned above the
 sending route of the box sheet 1, the tip 5a does not hit a face of the
 sending box sheet 1. Therefore a noise is not made and the face of the box
 sheet 1 is not damaged.
 A result of a test for measuring a noise of the apparatus for bending the
 box sheet which does not send the box sheet, and the apparatus for bending
 the box sheet according to the present embodiment, as well as a typical
 apparatus for bending the box sheet are all indicated in Chart 1.
 CHART 1
 Sending Speed 50 m/m 100 m/m 150 m/m
 The Apparatus for Bending 62 db 65 db 70 db
 the Box Sheet which is
 sending the box sheet
 The Apparatus for Bending 68 db 74 db 79 db
 the Box Sheet according to
 the present invention
 The Typical Apparatus for 76 db 80 db 83 db
 Bending the Box Sheet
 In the present embodiment, although the part 1b between the tip 1a and a
 first fold 2 of the sending box sheet is lifted up by rotating of the
 lifting arm 7, the part 1b may be lifted up by a cylinder. And although
 the lifting arm 7 is electrically controlled, it may be mechanically
 controlled.
 The present inventionbeing thus described, itwillbe obvious that the same
 maybe varied in many ways. Such variations are not to be regarded as being
 a departure from the spirit and scope of the present invention, and all
 such modification as would be obvious to one skilled in the art are
 intended to be included within the scope of the present invention as
 defined by the following claims.