GB2252269A

GB2252269A - Cross-cut saw assembly

Info

Publication number: GB2252269A
Application number: GB9127538A
Authority: GB
Inventors: Norman Leeper
Original assignee: WCK Ltd
Current assignee: WCK Ltd
Priority date: 1991-01-29
Filing date: 1991-12-31
Publication date: 1992-08-05
Anticipated expiration: 2011-12-31
Also published as: IE910293A1; GB2252269B; IE66889B1; GB9127538D0

Abstract

The cross-cut saw assembly (1) for cutting wood planks to desired lengths comprises a ground engaging support frame (2) with a pair of parallel beams (3, 4) on which a number of saw units (8, 9) are slidably mounted which are independently movable along the beams (3, 4) for selected relative spacing of the saw units (8, 9). Each saw unit (8, 9) has an independently driven circular saw (30). Feeder means is provided on each saw unit (8, 9) to deliver planks to the saws (30) and comprises an endless chain (38) having a number of spaced-apart outwardly extending workpiece feeders (39). Each chain (38) is independently driven by a motor (42) controlled by a microcomputer to operate on a continuous start-stop basis for stepped delivery of a plank to the saws (30). <IMAGE>

Description

"A Cross-Cut Saw Assembly" This invention relates to a cross-cut saw assembly, particularly a cross-cut saw assembly for cutting wood planks to desired preset lengths.

According to the invention there is provided a cross-cut saw assembly comprising a support frame, two or more parallel saw units mounted on the frame, each saw unit having a circular saw and feeder means to deliver a workpiece to the saw in use, at least one of the saw units being movable on the frame to adjust the distance between the saw units, drive means being provided for each movable saw unit to move the saw unit along a track on the frame.

In a preferred embodiment of the invention at least one of the saw units has a pivotally mounted saw movable on the saw unit between a cutting position and a stored position.

In another embodiment guide means is provided on the support frame to position a workpiece delivered to an inlet of the apparatus at a start position in which the workpiece is supported transversely across two or more saw units ready for engagement by the feeder means.

In a further embodiment the guide means is a conveyor belt extending transversely along the frame at an inlet end of the saw units, the conveyor belt being supported at each end on rollers and passing around each saw unit on rollers fixed at the inlet end of each saw unit, drive means being provided for the conveyor belt.

In another embodiment a waste conveyor is mounted beneath the saws to collect waste material cut from a workpiece by the saws in use. Preferably the conveyor is a vibrating conveyor, vibration of the conveyor urging the waste material to an outlet end of the conveyor, the outlet end having a screen mounted over a trough to filter the waste material which is delivered to associated waste collecting stations.

In a particularly preferred embodiment of the invention there is provided a cross-cut saw for cutting wood planks into desired preset lengths, the saw comprising a support frame having a pair of parallel spaced-apart beams, at least three saw units transversely mounted between the beams, the saw units movable on tracks extending along the beams, a rack and pinion drive means being provided for the saw units comprising motor driven pinions on each saw unit engagable with fixed racks extending along each beam, each saw unit having a circular saw and a feeder means comprising an endless chain having a number of spaced-apart outwardly extending workpiece engagement members, the chains drivable to urge a workpiece caught by the engagement members towards the saws in use, and a vibrating conveyor mounted below the saws to catch waste materials cut from planks in use and deliver the waste materials to a waste collecting station.

Preferably the feeder members are operable to move on a start-stop basis, and means is provided for correctly aligning the feeder members of all the saw units at the end of each step when the feeder members are stopped.

In another aspect the invention provides a workpiece feeder device comprising two or more independently driven feeder members operable to engage and move a workpiece along a preset desirable workpiece feed path, control means for operation of the feeders, sensing means to sense the position of the feeder members on the path operably connected to the control means, the control means operable to move the feeder members along the path in a number of steps on a start-stop basis, stopping the feeder members at preset positions along the path to bring all the feeder members into alignment at said positions.

The invention will be more clearly understood from the following description of an embodiment thereof, given by way of example only with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of a cross-cut saw assembly according to the invention; Fig. 2 is a plan view of the cross-cut saw; Fig. 3 is another plan view of the saw, in use; Fig. 4 is an elevational view of the saw assembly; Fig. 5 is an end view of the saw assembly; and Fig. 6 is a detail side elevational view of a saw unit forming portion of the saw assembly, the saw unit incorporating a pivoting saw.

Referring to the drawings there is illustrated a crosscut saw assembly indicated generally by the reference numeral 1. The saw assembly 1 comprises a support frame 2 having a pair of parallel spaced-apart beams 3, 4 mounted on ground engaging legs 5. In this case three saw units are provided comprising outer saw units 8 and an inner centre saw unit 9 mounted between the outer saw units 8. The saw units 8, 9 are transversely mounted between the beams 3, 4. Each saw unit 8, 9 is movable on tracks 12, 13 extending along a top of each beam 3, 4 respectively. Rollers 15 on each saw unit 8, 9 engage the tracks 12, 13. A rack and pinion drive means is provided for the saw units 8, 9 comprising pinions 20 on a drive shaft 21 driven by a motor 22 which engages fixed racks 24 extending along an under side of each beam 3, 4 (see Fig. 6).

Each saw unit 8, 9 has a circular saw 30 mounted between a pair of spaced-apart support plates 31. Each saw 30 is driven by its own motor 32 mounted on a support bracket 33 on one of the support plates 31, the motor 32 having a drive shaft 34 extending through an opening 35 in the support plate 31 to carry the saw 30. Feeder means is provided on each saw unit 8, 9 to deliver a workpiece to the saws 30 in use. In this case the feeder means comprises an endless chain 38 having a number of spacedapart outwardly extending workpiece feeders 39. Each chain 38 is drivable on sprockets 41 by means of a motor 42 mounted on one of the support plates 31. All the motors 42 are controlled by a microcomputer to operate on a continuous start/stop basis when delivering a work piece to the saws 30.This incremental feed of the work piece to the saws 30 allows all the work piece feeders 39 to come into alignment at the end of each step (when the motors 42 stop) thus overcoming the problem of synchronising the independent motors 42 and hence the feeders 39 for smooth correctly aligned delivery of a work piece to the saw 30. Alignment of the work piece feeders 39 is achieved by a light sensor (not shown) which senses when corresponding work piece feeders 39 on each saw unit 8 reach a pre-selected set point, stopping the associated motor 42 driving each work piece feeder 39 when the work piece feeder 39 reaches the set point.

In an alternative arrangement the chains 38 may be driven by a square drive shaft extending along one end of the saw units 8, 9 engagable with sprockets 41 to drive all the chains 38 together by means of a single motor, the sprockets 41 being slidable on the drive shaft to allow movement of the saw units 8, 9 on the beams 3, 4.

Guide means is provided to position a workpiece delivered to an inlet 50 of the apparatus 1 to a start position in which the workpiece is supported transversely across the saw units 8, 9 ready for engagement by the feeder means.

The guide means comprises a conveyor belt 52 extending transversely along the frame 2 at inlet ends of the saw units 8, 9 the conveyor belt 52 being supported at each end on rollers 53 and passing around each saw unit 8, 9 on rollers 54 mounted by support brackets 55 at inlet ends of the saw units 8, 9. It will be noted that the top workpiece carrying surface 58 of the conveyor belt 52 is supported above an upper edge of the support plates 31 in three separate sections, the size of each section varying with the positioning of the saw units 8, 9 along the frame 2. The rollers 54 allow free movement of the saw units 8, 9 along the frame 2 without interfering with the guide conveyor. A drive motor 60 is provided to operate the guide conveyor.

Extending beneath the saws 30 is a vibrating conveyor 65 (see Figs. 4 and 5). The vibrating conveyor 65 is generally of conventional type construction comprising a channel shaped trough 66 vibratable on a base 67 to deliver waste material to an outlet end 69 of the conveyor 65. The outer end 69 has a deepened trough portion 71 with a screen 72 mounted over the trough portion 71 to filter waste material delivered to the conveyor outlet 69 for delivery to waste collecting stations. As shown in Fig. 4 larger off-cuts 73 are caught by the screen 72 whereas sawdust 74 passes through the screen 72. The larger off-cuts 73 may be collected separately or they may be further processed to reduce them to sawdust and then bagged with the remainder of the sawdust.

Referring now in particular to Fig. 6 which shows the central saw unit 9, the saw 30 of which is pivotable between a cutting position and a stored position (shown in broken outline in Fig. 6). The saw drive motor 32 is in this case mounted on a platform 80 pivotally mounted at 81 on a support bracket 82 fixed to the support plate 31. A ram 85 is pivotally connected at 86 to the support bracket 82 below the platform 80. The other end of the ram 85 is connected by a pivot link 88 to a free end 89 of the platform 80, the pivot link 88 pivotally connected to the ram 85 and the platform 80. In use, the ram 85 is operable to pivot the saw 30 from a raised cutting position as shown in Fig. 6 and a lowered stored position shown in broken outline in Fig. 6.

In use, the saw units 8, 9 of the saw assembly 1 are spaced-apart on the frame 2 to cut a workpiece such as a plank 95 (indicated in broken outline) in Figs. 2 and 3 to desired preset lengths determined by the spacing of the saw units 8, 9. The plank 95 is delivered to the inlet 50 onto the top surface 58 of the conveyor belt 52, the conveyor belt 52 carrying the plank 95 to a start position in which the plank 95 is supported transversely across the saw units 8, 9 abutting an end stop 98 at one end of the frame 2. Then the feeder means are operated so that the workpiece feeders 39 engage the plank 95 and move it towards and through the saws 30. Each time the work piece feeders pause in their stepped movement a new plank 95 is loaded on the saw units 8,9. Cut plank portions are collected at an outlet end of the saw units 8, 9. Sawdust and off-cuts are collected by the conveyor 65.When only end trimming of the plank 95 is required then the saw 30 of the central saw unit 9 can be dropped to its stored position and with the outer saw units 8 adjusted to the required positions on the frame 2, the plank 95 can be trimmed to the required length.

It will be appreciated that the provision of independent drives for each saw unit allows the relative spacings between the saw units 8, 9 to be readily easily and quickly adjusted by driving the motors 22 to operate the rack and pinion mechanism. Heretofore the adjustment of the relative spacings of the saw units has been a lengthy and cumbersome task.

Any number of saw units may be provided on the support frame. In some cases fixed saw units may be provided at one or both ends of the support frame.

Various safety features such as guards around the moving parts have not been shown on the drawings for clarity.

The invention is not limited to the embodiment hereinbefore described which may be varied in both construction and detail.

Claims

1. A cross-cut saw assembly, comprising a support frame, two or more parallel saw units mounted on the frame, each saw unit having a circular saw and feeder means to deliver a workpiece to the saw in use, at least one of the saw units being movable on the frame to adjust the distance between the saw units, drive means being provided for each movable saw unit to move the saw unit along a track on the frame.

2. An assembly as claimed in claim 1 wherein at least one of the saw units has a pivotally mounted saw movable on the saw unit between a cutting position and a stored position.

3. An assembly as claimed in claim 1 or claim 2 wherein guide means is provided to position a workpiece delivered to an inlet of the apparatus at a start position in which the workpiece is supported transversely across two or more saw units ready for engagement by the feeder means.

4. An assembly as claimed in claim 3 wherein the guide means is a conveyor extending transversely along the frame at an inlet end of the saw units, the conveyor being supported at each end on rollers and passing around each saw unit on rollers fixed at the inlet ends at the saw units, drive means being provided for the conveyor.

5. An assembly as claimed in any preceding claim wherein a waste conveyor is mounted beneath the saws to collect waste material cut from a workpiece by the saws in use.

6. As assembly as claimed in claim 5 wherein the conveyor is a vibrating conveyor, vibration of the conveyor urging the waste material to an outlet end of the conveyor, the outlet end having a screen mounted over a trough to filter the waste material which is delivered to waste collecting stations.

7. A cross-cut saw assembly for cutting wood planks to desired preset lengths, the saw comprising a support fame having a pair of parallel spaced-apart beams, at least three saw units transversely mounted between the beams, the saw units movable on tracks extending along top faces of the beams, a rack and pinion drive means being provided for the saw units comprising motor driven pinions on each saw unit engagable with fixed racks extending along underside of each beam, each saw unit having an independently driven circular saw and feeder means comprising an endless chain having a number of spaced-apart outwardly extending workpiece feeder members, the chains drivable to urge a workpiece caught by the feeder members towards the saws, and a vibrating conveyor mounted below the saws to catch waste materials cut from planks in use and deliver the waste material to a waste collecting station.

8. A cross-cut saw assembly as claimed in claim 8 wherein the feeder members are operable to move on a start-stop basis, and means is provided for correctly aligning the feeder members of all the saw units at the end of each step when the feeder members are stopped.

9. A cross-cut saw assembly substantially as hereinbefore described with reference to the drawings.

10. A workpiece feeder device comprising two or more independently driven feeder members operable to engage and move a workpiece along a preset desirable workpiece feed path, control means for operation of the feeders, sensing means to sense the position of the feeder members on the path operably connected to the control means, the control means operable to move the feeder members along the path in a number of steps on a start-stop basis, stopping the feeder members at preset positions along the path to bring all the feeder members into alignment at said positions.