Information
-
Patent Grant
-
6736061
-
Patent Number
6,736,061
-
Date Filed
Friday, May 24, 200222 years ago
-
Date Issued
Tuesday, May 18, 200420 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Hirshfeld; Andrew H.
- Ferguson; Marissa
Agents
- Davidson, Davidson & Kappel, LLC
-
CPC
-
US Classifications
Field of Search
US
- 101 227
- 101 232
- 101 480
- 101 365
- 101 408
- 101 409
- 101 231
- 101 228
- 198 644
- 198 369
-
International Classifications
-
Abstract
A signature transfer device includes a rotating arm rotating about a first axis and a first gripper rotatably mounted on the rotating arm about a second axis, the first and second axes being parallel, the first gripper having a first gripper finger and a second gripper finger. An actuator is connected to the first gripper for opening and closing the first gripper as a function of the angle of the rotating arm about the first axis, and a compression spring connects the first gripper finger and the second gripper finger, the compression spring being compressed when the first gripper and the second gripper finger are apart.
Description
BACKGROUND OF THE INVENTION
The present invention relates generally to printing presses and more particularly to a signature transfer device for transporting printed products.
A web printing press, for example for newspapers, will print a continuous web of material. In a folder of the printing press, the web will be folded, if desired, and then cut, so that signatures result. The signatures can then be conveyed on a conveyor and then transferred by a signature transfer device to another conveyor for further processing or delivery.
U.S. Pat. No. 4,482,141 discloses a method and device for conveying signatures from a blade chain conveyor supporting the signatures directly at a fold line. The signatures are gripped from above by orbitally-rotating clamping pads, which then transfer the signatures to a belt conveyor perpendicular to the blade chain conveyor. A tension spring forces the gripper fingers together. This patent is hereby incorporated by reference herein.
European Patent Application No. 0771 675 A1 discloses a device for removing signatures from a saddle conveyor supporting the signatures. The conveyor has cutouts that permit the signatures to be gripped from above by a rotating clamping device, which then further conveys the signatures to a belt conveyor.
U.S. patent application No. 2001/00327741 discloses a device for removing signatures from a saddle conveyor that moves the signatures over cutouts in a sword. Grippers grip the outside of the signature from above and transfer the signatures to a further conveying device.
SUMMARY OF THE INVENTION
An object of the present invention is to permit efficient removal of signatures and transfer from a conveyor.
The present invention provides a signature transfer device comprising: a rotating arm rotating about a first axis; a first gripper rotatably mounted on the rotating arm about a second axis, the first and second axes being parallel, the first gripper having a first gripper finger and a second gripper finger; an actuator connected to the first gripper for opening and closing the first gripper as a function of the angle of the rotating arm about the first axis; and a compression spring connecting the first gripper finger and the second gripper finger, the compression spring being compressed when the first gripper and the second gripper finger are apart.
By using a compression spring, various signature thicknesses can be accommodated without the need for control elements. As the signature thickness increases, the spring force increases since the compression spring is further compressed. Complicated signature thickness adjustments are not necessary. Preferably, the signature thicknesses range between 0 and 2.5 cm.
Preferably, the actuator is a cam follower interacting with a cam on the arm.
Preferably, the signature transfer device includes a second gripper rotating about the axis. The first and second grippers may be supported rotatably on a rotating arm rotating about the axis.
Preferably, the compression spring is compressed less than 10% of its uncompressed length when the first gripper finger and second gripper finger are closed without holding a signature. The spring can thus be changed without danger of the compression spring provided too much force during the changing operation.
The first gripper finger preferably includes a support rod extending through the second gripper finger, the support rod supporting the compression spring.
The first gripper preferably includes a support, the first and second gripper fingers and the cam follower being rotatable with respect to the support. The first and second gripper fingers may be geared together, and the cam follower may rotate one of the gears.
The support rod preferably has a removable nut at one end to support one end of the compression spring. The other end of the spring preferably is supported by the support, the spring thus being indirectly connected to the second gripper finger via the support.
The spring preferably extends through the rotating arm, and may be surrounded by the support. A first pulley may be fixed to an outer surface of the support, the support and the first pulley thus being rotatable with respect to the arm, which may house the support at a bearing surface.
The arm preferably is rotated via a central shaft. A fixed pulley preferably surrounds the central shaft, and is connected for example to a frame of a printing press or to the ground, so that the central shaft rotates with respect to the fixed pulley. A first belt preferably runs between the fixed pulley and the first pulley, so that as the arm rotates, the first belt causes the first gripper to maintain its orientation. A second pulley may be attached to the second gripper and, through a second belt, to the fixed pulley.
The present invention also provides a printing press comprising a print unit for printing a material, a conveyor for moving a plurality of signatures formed from the material in a first direction, and a signature transfer device for transferring signatures downstream of the conveyor. The signature transfer device has a rotating arm rotating about a first axis and a first gripper rotatably mounted on the rotating arm about a second axis, the first and second axes being parallel, the first gripper having a first gripper finger and a second gripper finger; an actuator connected to the first gripper for opening and closing the first gripper as a function of the angle of the rotating arm about the first axis; and a compression spring connecting the first gripper finger and the second gripper finger, the compression spring being compressed when the first gripper and the second gripper finger are apart.
Preferably, the printing press is a web printing press, and further includes a folder for forming signatures from the web.
A signature lifting device can be provided to lift the signatures from the conveyor, or the signatures can be transferred directly from the conveyor.
“Gripper finger” as defined herein is any gripper part used to contact a signature.
BRIEF DESCRIPTION OF THE DRAWINGS
The following figures show a preferred embodiment of the present invention in which:
FIG. 1
shows a schematic side view of the printing press of the present invention;
FIG. 2
shows a perspective view of the one of the grippers of the signature transfer device of the present invention;
FIG. 3
shows a top view of the
FIG. 2
gripper;
FIG. 4
shows a view of the gripper through section A—A shown in
FIG. 3
; and
FIG. 5
shows a rear view of the signature transfer device according to the present invention.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
FIG. 1
shows a preferred exemplary embodiment of a web lithographic offset printing press according to the present invention having a print unit
113
printing a web
111
, which is then folded, if desired, and cut into signatures
118
,
120
,
122
in a folder
112
. The signatures are conveyed on a saddle conveyor
100
with a fold F of the signature being between two chains of the conveyor. Pushers
102
on the chains aid in moving the signatures.
The signatures may be lifted from the chain by a signature lifting device
110
passing between the chains and lifting the signature from below at the fold. Alternately, the signatures may be lifted directly from conveyor
100
or from a sword.
Signature transfer device
30
can then lift the signatures using grippers
22
,
24
rotatingly mounted on a rotating arm
20
, which rotates in a direction D. Grippers
22
and
24
rotate with respect to arm
20
so as to maintain a similar orientation, i.e. so that gripper edge E remains parallel to fold F or a direction of movement of conveyor
100
. Thus as signature
122
is lifted, one of the grippers
22
,
24
grips the fold F from the outside and transports the signature along transfer path P.
The opening and closing of the grippers
22
,
24
is controlled by cam followers
52
,
53
, respectively, running in cams
52
,
53
fixed to arm
20
. If the gripper
22
is considered to be at a 3 o'clock position, and gripper
24
at a 9 o'clock position, the cam activates the grippers
22
,
24
to close at the 6 o'clock position to grip the signatures, and then to open again at the 9 o'clock position to release the signatures to a further conveying device, such as a set of tapes.
FIGS. 2
,
3
and
4
show more details of one of the grippers
22
, the gripper
24
being substantially similar to gripper
22
. Gripper
22
has two gripper fingers
46
,
48
rotatably supported in supports
58
,
59
by shafts
56
,
54
, respectively, as shown best in FIG.
4
. Shafts
56
,
54
are fixed to gears
60
,
62
respectively, which are in turn geared together.
Attached to outer finger
46
is a settable fold stop
44
, which passes through finger
48
to ensure that the signature does not pass to high into the gripper
22
. The gripper fingers
46
,
48
also may have gripper pads
146
,
148
, respectively.
Fixed to outer gripper finger
46
is a support rod
73
, having a removable nut
70
at a free end. Rod
73
passes through inner gripper finger
48
at an aperture
49
. Rod
73
supports a linear compression spring
72
, which contacts the nut
70
at one end and support
58
at another end. Support
58
also includes a housing
76
surrounding spring
72
.
Support
76
has a first outer surface section
74
and a second outer surface section
75
.
As shown in
FIG. 5
, rotating arm
20
supports gripper
22
at one end and gripper
24
at another end. Gripper
22
is rotatingly supported in arm
20
, with support
76
passing through a hole in arm
20
, and second outer surface section
75
(
FIG. 4
) interacting with a bearing in the hole of arm
20
. A pulley
94
is fixed to first outer surface section
74
of support
76
. Pulley
94
has a toothed outer section, over which a belt
92
runs, with belt
92
interacting as well with a fixed pulley
90
.
Pulley
94
, and gripper
22
thus rotate together, and as arm
20
is rotated by central shaft
26
, belt
92
causes pulley
94
to rotate so as to preserve the orientation of gripper
22
. In other words, gripper edge E remains parallel to fold edge F as arm
20
rotates in direction D.
In order to control a tension on belt
92
, an adjustment roller
82
can be slid against a smooth outer surface of belt
92
. Adjustment roller
92
can move in slot
86
in arm
20
and be connected rotatably to arm
20
.
Fixed pulley
90
has two toothed sections, one interacting with belt
92
, and another interacting with a second toothed belt
96
, which is connected to a second pulley
98
connected at another end of arm
20
.
Second pulley
98
is fixedly connected to gripper
24
, and both gripper
24
and pulley
98
can rotate with respect to arm
20
, so that as arm
20
rotates, gripper
24
maintains its orientation, preferably so that the gripper edge remains horizontal.
An adjustment roller
84
can set the tension of belt
96
.
More than two grippers are also possible by replacing two-legged arm
26
with a three or more legged arm. “Signature” as defined herein can include single sheet or multi-sheet printed product. “Arm” as defined herein is any rotating support structure.
Claims
- 1. A signature transfer device comprising:a rotating arm rotating about a first axis; a first gripper rotatably mounted on the rotating arm about a second axis, the first and second axes being parallel, the first gripper having a first gripper finger and a second gripper finger; an actuator connected to the first gripper for opening and closing the first gripper as a function of the angle of the rotating arm about the first axis; and a linear compression spring connecting the first gripper finger and the second gripper finger, the compression spring being compressed when the first gripper and the second gripper finger are apart; the first gripper finger including a support rod extending through the second gripper finger, the support rod supporting the compression spring.
- 2. The signature transfer device as recited in claim 1 wherein the actuator is a cam follower interacting with a cam on the arm.
- 3. The signature transfer device as recited in claim 1 further including a second gripper rotating about the first axis.
- 4. The signature transfer device as recited in claim 3 wherein the first and second grippers are supported rotatably on the a rotating arm rotating about the first axis.
- 5. The signature transfer device as recited in claim 1 wherein the compression spring is compressed less than 10% of an uncompressed length when the first gripper is closed without a signature.
- 6. The signature transfer device as recited in claim 1 wherein the first gripper includes a support, the first and second gripper fingers and the cam being rotatable with respect to the support.
- 7. The signature transfer device as recited in claim 6 wherein the first and second gripper fingers are geared together.
- 8. The signature transfer device as recited in claim 1 wherein the support rod has a removable nut at one end to support one end of the compression spring.
- 9. The signature transfer device as recited in claim 6 wherein the spring extends through the rotating arm.
- 10. The signature transfer device as recited in claim 1 further comprising a first pulley fixed to the first gripper and rotatable with respect to the arm, a fixed pulley, and a belt connecting the first pulley and the fixed pulley.
- 11. The signature transfer device as recited in claim 1 wherein the fixed pulley surrounds a central shaft driving the arm.
- 12. A printing press comprising:a print unit for printing a material, a conveyor for moving a plurality of signatures formed from the material in a first direction, and a signature transfer device for transferring signatures downstream of the conveyor, the signature transfer device having a rotating arm rotating about a first axis and a first gripper rotatably mounted on the rotating arm about a second axis, the first and second axes being parallel, the first gripper having a first gripper finger and a second gripper finger, an actuator connected to the first gripper for opening and closing the first gripper as a function of the angle of the rotating arm about the first axis, and a linear compression spring connecting the first gripper finger and the second gripper finger, the compression spring being compressed when the first gripper and the second gripper finger are apart; the first gripper finger including a support rod extending through the second gripper finger, the support rod supporting the compression spring.
- 13. The printing press as recited in claim 12 wherein the printing press is a web printing press, and further including a folder for forming signatures from the web.
US Referenced Citations (8)
Foreign Referenced Citations (1)
Number |
Date |
Country |
0771675 |
May 1997 |
EP |