EP2921269B1

EP2921269B1 - Log clamping device and log saw comprising said clamping device

Info

Publication number: EP2921269B1
Application number: EP14425031.3A
Authority: EP
Inventors: Giovanni Bertoli Barsotti
Original assignee: Universal Tissue Technology Srl
Current assignee: Universal Tissue Technology Srl
Priority date: 2014-03-19
Filing date: 2014-03-19
Publication date: 2017-05-10
Anticipated expiration: 2034-03-19
Also published as: ES2634017T3; EP2921269A1; PL2921269T3

Description

Technical Field

The present disclosure generally relates to a log clamping device, and more particularly to a log clamping device associated with a cutting machine. The cutting machine is applied to cut "logs" comprising web material wound on tubular winding cores. The log clamping device clamps the log in the cutting process.
The disclosure also relates to a log saw comprising a clamping device.

Description of the Related Art

In typical applications, a log such as a wound tissue log is cut into rolls of smaller size by a blade or knife, e.g. a rotating circular knife, in a cutting machine. The log is held and supported by a clamping device in the cutting process.
A typical clamping device is configured for securing logs of constant size. Related structures of prior clamping devices may need to be replaced when the size of the logs is changed in order to properly clamp, making it inconvenient or inefficient to change log diameters. Therefore, there is a need for more efficient or flexible clamping systems for cutting logs.
GB-A-547 112 describes a device according to the preamble of claim 1.

Summary of the Invention

The invention is defined in claim 1.
According to some embodiments, the clamping device can further be comprised of at least one post. The base plate can be moveably connected to the at least one post. The post can be in the form of a screw, and the base plate can be threadedly engaged with the at least one post. The base plate moves relative to the frame via the rotation of the at least one post.
According to particularly advantageous embodiments, the clamping device can comprise a pair of arms moveably disposed on the base plate. The pair of clamps can be connected to the pair of the arms respectively.
To make adjustment of the distance between the arms, according to some embodiments a follower can be rotatably formed or mounted on each arm. A profile can be fixed on the frame corresponding to the follower. The profile has a surface on which the follower moves along to change the distance between the arms.
In some embodiments the follower on one arm and a corresponding profile are symmetrical with respect to the follower on another arm and another corresponding profile relative to a vertical plane parallel to the longitudinal axis of the log and passing through a central region of the clamping device.
According to one embodiment, one clamp is fixed onto one arm, and another clamp is pivotably connected to another arm. The another clamp can be capable of rotating between a clamping position and an open position, to facilitate advancing of the log through the clamping device during the cutting process.
An arm actuator can be connected to each arm for changing the distance between the arms.
According to a further aspect, the invention concerns a log cutting machine comprising a log advancing conveyor, a log cutting knife and a log clamping device as disclosed herein.

Brief Description of the Drawings

FIG. 1 is a front-side view of a clamping device of an exemplary embodiment of the present disclosure, wherein logs are shown in the clamping device.
FIG. 2 is a cross-sectional view of the clamping device of FIG. 1, taken along line II-II thereof.
FIG 3 is another front-side view of the clamping device of FIG. 1, wherein the diameter of the logs is larger than that in FIG. 1.
FIG 4 is a cross-sectional view of the clamping device of FIG. 3, taken along line IV-IV thereof.
FIG 5 is a cross-sectional view of a clamping device of another exemplary embodiment of the present disclosure.

Detailed Description of Embodiments

Referring to FIG. 1 and FIG 2, a clamping device 1 in accordance with an exemplary embodiment of the present disclosure is shown for holding and supporting a circumferential surface 101 of a log 100 in a cutting process, in which the log 100 is cut by a cutting machine into rolls of smaller sizes. The log 100 can be a tissue log or other kinds of web material wound on a tubular winding core 102. The cutting machine, also named log saw machine, is comprised of a log advancing conveyor and a log cutting knife, which can be e.g. a circular rotating knife. These components of the log saw are well known to those skilled in the art and are not described in greater detail herein.
The clamping device shown in FIG. 2 has two clamping units 2 and 3 for holding two lanes of logs 100. The two clamping units 2 and 3 have similar structures. In alternative embodiments, the clamping device may have one clamping unit for holding a single log 100, or may be provided with more than two clamping units for holding more than two logs 100.
The clamping device having one clamping unit is set forth as an example for a detailed description as follows. The clamping device comprises a frame 10, a supporting beam 11 fixed on the frame 10, a base plate 12, a pair of arms 131, 132 disposed on the base plate 12 and a pair of clamps 141, 142 respectively connected to the arms 131, 132. The clamp 141 is fixed on the arm 131. The clamp 142 is pivotably connected to the arm 132, and is capable of rotating and shifting between a clamping position and an open position. The log 100 is supported on the supporting beam 11. As shown in FIG. 2, when the clamp 142 is in the clamping position, the supporting beam 11 locates at a bottom of the circumferential surface 101 of the log 100 and the clamps 141, 142 are symmetrically located at opposite sides of the circumferential surface 101 of the log 100. The supporting beam 11 and the clamps 141, 142 cooperate to secure the log 100 for facilitating the cutting process of the log 100. When the clamp 142 is in the open position (dotted lines shown in FIG. 2), the log 100 will be unrestrained among the supporting beam 11 and the clamps 141, 142. The supporting beam 11, in typical embodiments, does not move vertically when the base plate 12 moves vertically, but remains at a substantially constant elevation to support logs. In one embodiment, when the clamp 142 is in the open position, the minor distance d between the clamps 141, 142 (i.e., the distance d between free ends 143, 144 of the clamps 141, 142 as shown in FIG. 2) increases allowing the log 100 to move between the clamps 141, 142 more easily to allow new regions of the log 100 to be cut.
Multiple pairs of arms and clamps can be arranged along the axial direction of the log 100 as desired. Two clamps 142a, 142b are shown in FIG. 1 and are distributed along the axial direction of the log 100. Accordingly, the supporting beam 11 can extend to a predetermined length along the axial direction of the log 100 for holding the log 100.
For conforming with the circumferential surface 101 of the log 100, the clamps 141, 142 may have a curved shape in some embodiments. The clamps 141, 142 can be configured to include sub-clamps for increasing a contacting surface between the clamps 141, 142 and the log 100. The clamps 142a, 142b shown in FIG. 1 each have two sub-clamps 145 and in some embodiments may present a U shape or other suitable shapes. The distance between the sub-clamps 145 of the clamp 142a is smaller than that of the clamp 142b. Alternatively, the clamp 141 can have a similar structure to the clamp 142, but need not similar but may have any suitable shape known in the art. In addition, the arms 131, 132 can each include sub-arms for connecting a corresponding sub-clamp 145.
The clamp 142 is connected to an actuator 15. The actuator 15 drives the rotation of the clamp 142 relative to the arm 132 between the clamping position and the open position.
The actuator 15 is positioned beneath the base plate 12, and penetrates through the base plate 12 to connect the clamp 142. The actuator 15 can be a pneumatic cylinder, a hydraulic cylinder or other equivalent structures. A motor 150 is used to move a pusher (shown behind the right-hand log in Figs. 2, 4 and 5) that moves the log 100 into position to be clamped and moves the log 100 away from the clamps 141, 142 after cutting is completed.
The supporting beam 11 extends upwardly from the frame 10 and comprises two troughs 111, 112. The section profile of the supporting beam 11, including the respective troughs, is substantially a Y shape or a V shape, though other shapes may be contemplated such as a more curved, less angular shape capable of holding the log 100. The troughs 111, 112 contact and help support the bottom of the circumferential surface 101 of the log 100.
An advancing conveyor, e.g. an endless belt or chain, can be guided in the beam 11. Log pushers can be connected to the advancing conveyor, for pushing the logs in an advancing direction through the log saw or log cutting machine. In Figs. 2, 4 and 5 the log pushers are shown behind the right-hand log, while the pushers are omitted from the left-hand log. The logs slide, under the thrust of the pushers, on the surfaces of the troughs 111, 112.
In some embodiments such as the embodiment shown in FIG. 2 and FIG. 4, the clamping device may further comprise a cam mechanism corresponding to each arm 131(132). The cam mechanism comprises a profile 16 fixed on the frame 10, and a follower 17 disposed on the arm 131(132) to match with the profile 16. The profiles 16 for the two cam mechanisms corresponding to the arms 131, 132 may be symmetrical relative to the center of the two clamping units 2, 3, as shown in FIG. 2 and FIG. 4, or, in other words, can be mirror images of one another reflected about a vertical plane parallel to the axis of the logs and normal to the plane of FIG. 2, passing through a central region of the clamping device. The profile 16 shown in the embodiment has a bottom end near the base plate 12 and an opposite top end far from the base plate 12. The profile 16 as depicted has a surface 161 matching with the follower 17, and gradually slant from the bottom end to the top end thereof. Of course, a wide variety of other profile shapes can be used, including substantially linear profiles and profiles with more complex curves or both linear and curved sections. The distance between the two profiles 16 increases gradually from the bottom ends to the top ends thereof. When the follower 17 moves along the surface 161 of the corresponding profile 16, the distance between the two arms 131, 132 is changed gradually. More specifically, when the follower 17 moves upwardly along the surface 161 from the bottom end to the top end of the profile 16, the distance between the arms 131, 132 is increased gradually. When the follower 17 moves downwardly along the surface 161 from the top end to the bottom end of the profile 16, the distance between the arms 131, 132 is decreased gradually.
The base plate 12 is moveably connected to at least one post 18. FIG. 2 shows two posts 18 connecting the base plate 12. When the base plate 12 moves along the posts 18 downward or upward, as a result, the distance between the base plate 12 and the supporting beam 11 and the distance between the clamps 141, 142 and the supporting beam 11 is changed, thereby allowing the clamping device to be suitable for clamping logs 100 with different diameters.
In the present embodiment, the posts 18 are depicted as screws, and the base plate 12 is threadedly engaged with the posts 18, though other mechanisms may be used for moving the base plate 12. The posts 18 as shown can be rotated by a motor 19, and the base plate 12 is moved along the posts 18. The motor 19 can be fixed on the frame 10.
The arms 131, 132 are moveably connected to the base plate 12. For example, the arms 131, 132 can be slidably disposed on the base plate 12. In the present embodiment, rails 121 and tracks 122 are formed between the arms 131, 132 and the base plate 12 to accomplish the slidable movement between the arms 131, 132 and the base plate 12.
The follower 17 is rotatably arranged on the arm 131, 132 and engages with the surface 161 of the profile 16 fixed on the frame 10. Through the motion of the follower 17, the arm 131, 132 can slide on the base plate 12, and the distance between the clamps 141, 142 (as well as that between the arms 131, 132) can be changed. The follower 17 can also be controlled to stop at a desired position to maintain a fixed distance between the arms 131, 132. In alternate embodiments, the follower 17 can be driven directly by a motor (not shown) or other power supply or other device such as an airbag or pneumatic cylinder (not shown).
With the upward or downward movement of the base plate 12 relative to the supporting beam 11, the distance between the clamps 141, 142 and the supporting beam 11 (i.e., the vertical position of the clamps 141, 142, the arms 131, 132, and the base plate 12) can be adjusted. At the same time, with the rotation of the follower 17, the arms 131, 132 can slide on the base plate 12 and the distance between the arms 131, 132 (i.e., the horizontal position of the arms 131, 132 and the clamps 141, 142) can be adjusted. As a result, the supporting beam 11 and the clamps 141, 142 can be adjusted to hold and support logs 100 with different diameter, and there is no need to replace relative parts of the clamping device, which is more convenient and rapid in production.
The operation principles of the clamping device provided in the present disclosure will be more detailed described as follows referring to FIG 3 and FIG 4. The logs 200 shown in FIG 3 and FIG. 4 have a larger diameter than the logs 100 shown in FIG. 1 and FIG. 2.
If the clamping device as shown in FIG. 1 and FIG. 2 needs to hold and support the logs 200 as shown in FIG. 3 and FIG. 4, the posts 18 rotate, and the base plate 12 moves upwardly to increase the distance between the supporting beam 11 and the clamps 141, 142; at the same time, the follower 17 rotates and moves upwardly along the surface 161 of the profile 16, and the arms 131, 132 slide on the base plate 12, whereby the distance between the arms 131, 132 and between the clamps 141, 142 is increased. After the rotation of the clamp 142, where the clamp 142 is in the open position, the log 200 can be inserted among the supporting beam 11 and the clamps 141, 142. The log 200 is then secured by the supporting beam 11 and the clamps 141, 142 after a reversed rotation of the clamp 142, where the clamp 142 is in the clamping position.
In the above embodiment, the arms 131, 132 are moveably arranged on the frame 10 via the cam mechanisms to change the horizontal positions thereof. It is noted that the arms 131, 132 can be moveably arranged on the frame 10 in different manners, including configurations without the need for the profile 16 and the follower 17 of FIG. 2. Referring to the alternative embodiment shown in FIG. 5, each arm 131, 132 is connected to an arm actuator 20. The arm actuator 20 may be an electric, pneumatic, or hydraulic actuator, and may comprise an electric motor. The horizontal positions of the arms 131, 132 on the base plate 12 can be changed by the driving of the arm actuator 20. In other words, the distance between the arms 131, 132 can be adjusted by the driving of the arm actuator 20. In such way, the horizontal positions of the arms 131, 132 and the vertical positions of the arms 131, 132 can be controlled independently.
In alternative embodiments, the arm actuator 20 can be a rack and pinion system formed between the arms 131, 132 and the base plate 12.
Further, the moveable connection between the base plate 12 and the post 18 is not limited to screws. Other systems such as linear actuators, or rack and pinion can also be formed between the base plate 12 and the post 18 to accomplish the vertical position adjustment of the base plate 12.
It is to be further understood that even though numerous characteristics and advantages have been set forth in the foregoing description of embodiments, together with details of the structures and functions of the embodiments, the disclosure is illustrative only; and that changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the claims.

Claims

A clamping device for clamping a log, the clamping device comprising:
- a frame (10);

- a supporting beam (11) fixed on the frame for supporting the log (100, 200);

- a pair of clamps (141, 142) for clamping the log; and

- a base plate (12) for carrying the pair of clamps (141, 142), the pair of clamps moveably disposed on the base plate for changing the distance between the clamps (141, 142), characterized by the base plate (12) being moveably disposed on the frame (10) for changing the distance between the clamps (141, 142) and the supporting beam (11), thereby allowing the clamping device to be suitable for clamping logs of different diameters.
The clamping device of claim 1 further comprising at least one post (18), the base plate (12) moveably connected to the at least one post.
The clamping device of claim 2, wherein the at least one post (18) is a screw, the base plate (12) is threadedly engaged with the at least one post, and the base plate moves relative to the frame (10) via the rotation of the at least one post (18).
The clamping device of claim 1 or 2, further comprising a pair of arms (131, 132) moveably disposed on the base plate (12), the pair of clamps (141, 142) being connected to the pair of the arms (131, 132) respectively.
The clamping device of claim 4, wherein a follower (17) is rotatably formed on each arm (131, 132), a profile (16) is fixed on the frame (10) corresponding to the follower (17), the profile (16) has a surface (161) on which the follower (17) moves along to change the distance between the arms (131, 132).
The clamping device of claim 5, wherein the follower (17) on one arm (131) and a corresponding profile (16) are symmetrical with respect to the follower (17) on another arm (132) and another corresponding profile (16) relative to a vertical plane parallel to the longitudinal axis of the log and passing through a central region of the clamping device.
The clamping device of claim 4 or 5 or 6, wherein one clamp (141) is fixed onto one arm (131), and another clamp (142) is pivotably connected to another arm (132) and wherein the another clamp (142) is capable of rotating between a clamping position and an open position.
The clamping device of any one of claims 4 to 7, wherein an arm actuator (20) is connected to each arm (131, 132) for changing the distance between the arms (131, 132).
The clamping device of claim 4, wherein a rail (121) and a track (122) are formed between the arm (131, 132) and the base plate (12) to provide a slidable movement between the arm (131, 132) and the base plate (12).
The clamping device of claim 9, wherein a follower (17) is rotatably arranged on each arm (131, 132), a profile (16) is fixed on the frame (10) corresponding to the follower (17), the profile (16) has a surface (161) on which the follower (17) moves along to change the position of the arm (131, 132) on the base plate (12), thereby changing the position of a corresponding clamp (141, 142) on the base plate (12).
The clamping device of claim 9 or 10, wherein an arm actuator (20) is connected to each arm (131, 132) for changing the horizontal position of the arm (131, 132) on the base plate (12).
The clamping device of any one of claims 4, 9-11, wherein one (141) of the pair of clamps (141,142) is fixed onto one (131) of the pair of arms (131, 132), and another (142) of the pair of clamps (141, 142) is pivotably connected to another (132) of the pair of arms (131, 132) and capable of rotating between a clamping position and an open position.
The clamping device of claim 12 further comprising an actuator (15) connecting the another (142) of the pair of clamps (141, 142), the actuator (15) driving the another (142) of the pair of clamps (141, 142) to drive the rotation of the another of the pair clamps between the clamping position and the open position.
The clamping device of claim 13, wherein the actuator (15) is positioned beneath the base plate (12), and penetrates through the base plate (12) to connect the another (142) of the at least one pair clamps (141, 142).
The clamping device of any one of claims 4, 9-13, wherein the at least one post (18) is a screw, the base plate (12) is threadedly engaged with the at least one post (18), and the base plate (12) moves relative to the frame (10) via the rotation of the at least one post (18) to change the vertical position of the base plate (12), thereby changing the vertical position of the pair of clamps (141, 142); wherein a motor (19) is preferably provided for driving the at least one post (18), and wherein said motor (19) is preferably fixed on the frame (10).
A log cutting machine comprising a log advancing conveyor, a log cutting knife and a log clamping device according to any one of the preceding claims.