EP0195423A1

EP0195423A1 - Dual overhead endogging system

Info

Publication number: EP0195423A1
Application number: EP86103689A
Authority: EP
Inventors: Theodore Charles Foster
Original assignee: KOCKUMS CANCAR Inc
Current assignee: KOCKUMS CANCAR Inc
Priority date: 1985-03-19
Filing date: 1986-03-19
Publication date: 1986-09-24
Also published as: FI861132A0; CA1266870A; FI861132L; FI861132A7

Abstract

An endogging apparatus using twin reciprocally moving carriages (103, 104), each with connected dog means (129). One of the carriages grasps the log (136) from a log charger with its dog means (129) and transports the log (136) to and through breakdown elements. The second carriage moves from the location of the breakdown elements to the charger to grasp a second log (136) with its dog means (129). The dog means (129). on the carriages (103,104) are offset and retractable to allow passage of the two carriages when one carriage is transporting a log (136) through the breakdown elements with extended dog means (129) and the second carriage is returning unloaded to the charger with retracted dog means (129).

Description

This application relates to an endogging log transport apparatus and, more particularly, to an endogging appar&tus with dual carriages for transporting logs from a log charger and through log breakdown elements.
Endogging carriages are used in lumber mills to transport unprocessed logs from a log charger through the breakdown elements such as chippers, bandsaws, circle saws and the like. The carriage has dogs mounted thereon which grasp the log, remove it from the log charger and transport it lengthwise through the log breakdown elements where the log is processed. The carriage then returns unloaded from the breakdown elements to the log charger where it retrieves another log and repeats the process.
The process is inefficient. While the log charger has the capability of supplying a steady stream of logs to the carriages with little delay therebetween, there is a lengthy time delay between successive log grasping steps while the carriage moves the first log from the charger through the log breakdown elements and returns. While the speed of the process may be increased by providing well functioning machinery, it is inherently limited by the process. While it has been possible to provide a second carriage, such a carriage could only be used with an additional charger and additional breakdown equipment which, again, is inefficient for precisely the same reasons as explained.
Yet another disadvantage in present log transport apparatus is the arrangement used to prevent the carriages transporting logs from leaving the rails on which they move. The loads applied to the carriages when grasping, transporting and releasing logs are unpredictable, include impacting and act in a variety of directions on the carriages which tend under some conditions to remove the carriage from the rails. To obviate this possibility, a "hold down^* wheel has been used which acts vertically downwardly on the carriages and thus prevents the carriages from moving upwardly off the rails. This requires additional equipment and increases costs.
According to one aspect of the invention, there is disclosed an endogging system comprising first and second carriage means mounted on opposite sides of a vertical plane, each of said carriage means being operable to transport a log from a first location located substantially on said vertical plane to a second location and to return to said first location without said log, each of said carriage means having twin carriages, each of said carriages including dog means extending downwardly therefrom, each of said dog means being offset from said vertical plane whereby said first and second carriage means may pass when said dog means of said first carriage means are in said transport mode and said dog means of said second carriage means are in said retracted mode.
According to a further aspect of the invention, there is disclosed a method of transporting logs from a first to a second location comprising the steps of grasping a first log with dog means of a first carriage means in said first location, moving said log with said first carriage means to said second location while moving a second carriage means and dog means from said second location to said first location, releasing said first log at said second location, grasping a second log with said dog means of said second carriage means at said first location, moving said second log with said second carriage means to said second location, moving said first carriage means to said first location, and releasing said second log at said second location.
According to yet a further aspect of the invention there is disclosed a bearing arrangement for a log transport carriage means comprising a first and second rail means, a carriage means reciprocal on said first and second rail means, first and second bearing means between said first and second rail means and said carriage means, each of said bearing means being positioned about and in contact with each of said rail means and being operable to transfer variable loading on said carriage means to said rail means.
According to a further aspect of the invention there is disclosed an endogging system comprising log charger means, reciprocal first and second carriage means, each of said carriage means being operable to longitudinally transport a log from said log charger means to a second location along a first and second vertical plane, respectively, dog means mounted on each of said carriage means having an extended log transport and a retracted mode, said charger means being alternately moveable between said first and second vertical planes to cooperate with the reciprocal movement of said carriage means.
According to yet a further aspect of the invention, there is disclosed a log transport method comprising the steps of providing a first log at a first location with a log charger means, grasping said log at said first location with a first set of dogs extending from a first carriage means, transporting said log with said first carriage means through a log processing station, releasing said log after passage through said log processing station and returning said first carriage means to said first location, providing a second log at a second location with said log charger means, grasping said second log at said second location with a second set of dogs extending from a second carriage means, transporting said second log through said log processing station, releasing said second log and returning said second carriage means to said second location, said charger alternately providing said first and second logs at said first and second locations, said first and second carriage means having reciprocating and oppositely opposed movement between said first and second locations and said log processing station.
According to yet a further aspect of the invention, there is disclosed an endogging system comprising log charger means, reciprocal first and second carriage means, each of said carriage means being operable to longitudinally transport a log from said log charger means to a second location along a first and second vertical plane, respectively, dog means mounted on each of said carriage means and being operable to carry and transport logs, and log processing means moveable between said first and second planes to receive a log transported by said first and second carriage means respectively.
According to yet a further aspect of the invention, there is disclosed a log transport method comprising the steps of providing a first log at a first location, grasping said first log at said first location with a first set of dogs extending from a first carriage means, transporting said log with said first carriage means through a log processing station substantially on a first vertical plane, releasing said log after passage through said log processing station and returning said first carriage means to said first location, providing a second log at a second location, grasping said second log with a second set of dogs extending from a second carriage means, transporting said log through said log processing station substantially on a second vertical plane, releasing said log after passage through said log processing station and returning said second carriage means to said second location, said log processing station being alternately moveable between said first and second vertical planes to receive said logs from said first and second carriage means, respectively.
A specific embodiment of the invention will now be described, by way of example only, with the use of drawings in which:

Figure 1A is an elevation view of the dual overhead endogging system according to the invention;
Figure 1B is an enlarged partial elevation view of the area 105 of Figure 1A;
Figure 2A is a section view taken along 2-2 of Figure lA;
Figure 2Bis an enlarged partial sectional view of the carriage, bearing system and extended dogs of Figure 2A;
Figure 2C is a partial view of one carriage pair particularly illustrating the cable and chain drive adjustment method;
Figure 2_D is a partial view of one carriage pair particularly illustrating the hydraulic cylinder drive adjustment method;
Figure 3 is a plan view of the apparatus illustrated in Figure lA;
Figure 4 is a view depicting an alternative embodiment of the endogging system; and
Figure 5 is a plan view of the log processing and breakdown elements located adjacent to and on the same centre line as the dual carriage system of Figure lA.

Referring now to the drawings, a dual overhead endogging system is shown generally at 100 in Figure lA. It comprises a support frame generally shown at 101, dual carriage means generally shown at 102 (Figure 3) comprising a respective pair of carriages 103, 104 and four husk and dog means generally shown at 105, each husk and dog means 105 being connected to a respective one of the carriages 103, 104.
As seen in Figure 2B, the support frame 101 comprises a series of box members 106 which support "I" members 107 which are mounted on the box members 106 and which extend the length of the endogging system 100 to form longitudinal frame members. Inverted "T" members 108 are mounted on the I members 107. Round shafting or rails 109 are mounted on the top of each "T" member 108 and the shafting substantially extends the length of the "T" members 108.
Each of the carriages 103, 104 is mounted on the round shafting 109 by using bearing housings 110, 111, respectively, connected thereto, each housing 110, 111 containing a plurality of roundway bearings 112 (Figure _2B. The single bearing housing 110 on each of the carriages 103, 104 contains two roundway bearings 112 mounted approximately 120 degrees apart with one of the bearings 112 being located directly above the round shafting 109 as depicted and the other located below the horizontal plane 113 passing through the rails 109. Each of the second bearing housings 111, two of which are used on each carriage, contains three roundway bearings 112 spaced substantially equidistantly around the shafting 109, one bearing 112 being located directly above the shafting 109. Bearing housing 110 is mounted on the outer arm 114 of carriages 103, 104 as viewed in Figures 2A and 3 and bearing housings 111 are mounted on the inner arm 115 of carriages 103, 104, one housing 110 being located at each end of each carriage 103, 104, it being understood that the terms "outer" and "inner" are each used with respect to the vertical plane 116 which bisects the endogging system 100 as seen in Figure 3. "Inwardly" is directed towards the vertical plane 116 and "outwardly" is directed away from the vertical plane 116.
As best seen in Figure 2_C and 3, each pair of carriages 103, 104 is connected by a combination chain cable drive system generally shown at 117. Two main carriage drive pulleys 118, 119, each mounted independently on separate shafts 120, 121 are powered by respective hydraulic or electric motors . Cables 122 are wrapped around each pulley 118, 119. One end of each cable 122 is attached to one end of each respective carriage 103, 104 and the other end of each cable 122 from pulleys 118, 119 passes around idler pulleys 123, 124 and is connected to the opposite end of carriages 103, 104, respectively. As seen in Figure 2C, a chain 125 is connected to the ends of each cable 122. One of each pair of carriages 103, 104 is connected directly to the chain 125 and the other of each pair of carriages contains a chain wrap and pulley system generally shown at 126 so that by activating the hydraulically powered pulley system 126, the distance between each pair of carriages 103, 104 may be lengthened or shortened as required by the length of the log being transported. A hydraulic cylinder 127 (Figure lA) is connected to each of the roller pulleys 123, 124 and is used for tightening the chain wrap and pulley system 126.
Referring to Figures 1A and 1B, husks 128 are mounted on the carriages 103, 104 and retractable dogs 129 are pivotably connected to the husks 128. An actuating linkage 130 extends between the husks 128 and the retractable dogs 129, each actuating linkage 130 being operated by a hydraulic cylinder 131.
As best seen in Figures 2A and 2B, the dogs 129 are offset from the husks 128; that is, each dog 129 extends downwardly from the husks l28 and then inwardly towards the vertical plane 116 of the endogging system 100 so that the gripping portion of the dogs 129 is centered on the vertical plane 116. The transition area 132 of each of the dogs 129 extends inwardly at a distance sufficiently below the husks 128 so that the husks 128 of the carriages 103, 104 may freely pass as they reciprocate during movement on the round shafting 109 with one of the pair of carriages 103, 104 having its dogs 129 in the retracted position when the other of the pair of carriages 103, 104 having its dogs 129 in the extended position as seen in Figure lA.
With reference to Figures lA and 2A, a log charger is generally shown at 133 and is positioned below and alongside the carriages 103, 104 and support frame 101. It includes a plurality of yoke guides 134 which are moveable horizontally in the direction indicated in Figure 2A together with the yokes 135 which move vertically with respect to the yoke guides 134 to position a log 136 for pickup by the respective dogs 129 of the carriages 103, 104. A horizontal and vertical bank of photocells form horizontal and vertical scanner lines 137, 138, respectively, in the log charger 133 and a series of even ending rollers (not shown) are positioned between the yoke guides 134.
A log turner and stop and loader system is generally shown at 139 in Figure 2A. One such system is located on each side of the charger 133. Breakdown and log processing elements 140 (Figure lA) such as chippers, bandsaws, circle saws and the like are located adjacent the log charger 133.

OPERATION

In operation, logs enter the log charger 133 from one or both sides although a log 136 is shown on one side only in Figure 2A. The incoming log 136 is stopped and positioned such that even ending rolls (not shown) rotate and drive the log 136 against the "zero line" 141 of the support frame 101. The log turner will subsequently be rotated until a "horns up" log position is preferably reached, all of these operations being performed by the log turner and stop and loader system 139. The yoke guides 134 of the log charger 133 will move beneath the log 136 and the appropriate yokes 135, depending on log length, will move vertically relative to the yoke guides 134, and raise the log 136. As the log 136 is raised, it passes through horizontal scanner line 137 which defines the vertical log configuration for the processing elements. The yoke guides 134 will move horizontally towards vertical plane 116 until the log 136 is in the pickup position. While it moves towards the pick up position, the vertical scanner line 138 is passed which gives the horizontal log definition for the processing elements. The skew yoke guide 142 will move the log 136 in a plane transverse to the vertical plane 116 and the yokes 135 will raise the log 136 vertically until the optimum log processing position is reached. The log 136 is then ready for pickup.
When the optimum log processing position is reached by the log charger 133, the skew yoke guide 142 and the yokes 135, sensing devices (not shown) instruct the system control (not shown) to drop the dogs 129 by energizing hydraulic cylinders 131 (Figures 1A and 1B). The leftwardly located husk 128 will be moved under the influence of the chain wrap and pulley system 126 to the proper log length whereupon the dogs 129 will contact the log 136 at both ends with the appropriate retaining force. When a proximity switch (not shown) is triggered, the yokes 135 will move downwardly and out of contact with log 136, and the carriages 103 will commence rightwardly movement as viewed in Figure 3 while grasping the log 136 by energizing main carriage drive pulley 118.
As the carriages 103 move rightwardly with the log through the breakdown elements 140, the loading caused by the passage of the log 136 through the breakdown elements is transferred to the dogs 129, the husks 128, and, thence, to the carriages 103. The carriage loading has a tendency to lift the carriages 103 off the rails 109 but since the roundway bearing 112 in the bearing housings 110 contact the rails 109 substantially around their periphery, all loading is transferred to the rails 109 and thence to the support frame 101 or ground, on which the rails 109 are supported. Thus, the carriages 103 remain on the rails 109 throughout their reciprocal movement.
Carriages 104 meanwhile are moving leftwardly with the dogs 129 in their retracted position as shown in Figure lA. As log 136 enters and clears the initial log processing and breakdown elements 140, the dogs 129 are retracted by a position transducer (not shown) which energizes hydraulic cylinders 131 and moves actuating linkage 130. The log 136 is released and continues to travel under the influence of rollers (not shown) to further processing stations downstream.
Prior to log 136 entering the log processing station, the carriages 103, 104 will pass each other on opposite sides of vertical plane 116 as best seen in Figure 1A as they reciprocate with the dogs 129 of carriages 104 being in the retracted position.
Meanwhile, carriages 104 will have reached their leftwardmost pickup position with reference to Figure 3 and the dogs 129 are extended to grasp the next log 136 which is in a raised and optimum position on the yokes 135 and which is substantially on the vertical centre plane 116. This log 136, however, will have been provided to the log charger 133 from the rightward position as viewed in Figure 2A. The dogs 129 of carriages 104 will then grasp the log 136 and move it longitudinally from the pickup location to the log processing elements 140 as earlier described. While carriages 104 transport log 136 to the processing elements 140, carriages 103 are returning to the log pickup location with their dogs 129 retracted. Again with reference to Figures 1A and 2A, the carriages 103, 104 pass as explained on opposite sides of the vertical centre plane 116 and the system repeats its functioning as earlier described.
Many modifications are contemplated in the system just described. For example, the chain wrap and pulley system 126 illustrated in Figure 2C could be replaced by a hydraulic cylinder closing arrangement 143 illustrated in Figure 29. In this arrangement, the hydraulic cylinder 144 is connected directly to husk 128 and piston 145 is connected to the oppositely located husk 128 as depicted. The correct length adjustment between the extended dogs 129 is obtained by extending and retracting the piston rod 145 from hydraulic cylinder 144. This configuration is particularly applicable to shorter logs such as stud logs.
A further embodiment of the dual endogging system 100 is depicted in Figure 4. In this embodiment, the dual carriages 103, 104'each reciprocate on round shafting or rails 109"but rather than have the two sets of dogs 129' offset to grasp a log 136 from a single vertical plane, the log charger 133 is designed to alternately position a log for pickup at two offset vertical planes 146, 147 corresponding to the vertical planes of movement of the dogs 129 without the necessity of providing an offset. In this embodiment, the dogs 129 would continue to be moveable between their retracted and extended transport positions to prevent interference during their reciprocal adjacent side by side movement as one set of dogs 129' carries the log through the breakdown elements and the other set of dogs 129'returns. Roundway bearings 112, again trapping the shafting 109', would continue to provide appropriate load transfer for the loading on the carriages 103; 104'caused by the transportation of the logs. The log processing elements, however, and in particular, the chipper heads 150 would also reciprocate side to side in association with the log charger 133 as depicted in Figure 5 so that it would be in the correct position to receive a log being transported by each carriage pair. Figure 5 further depicts the pressure rolls 151, a band mill system 152 and the outfeed table 153. The breakdown and log processing elements 140 receive the logs 136 transported by each carriage pair 103, 104.
A further embodiment of the invention again contemplates two offset vertical planes of movement by the carriages and their attached dogs without offsetting the dogs 129. In this embodiment, it is contemplated that the log processing elements 140 would move between the two planes as depicted in Figure 5 so as to alternately receive logs from the first and second carriage pair 103, 104 during their reciprocal movement. In this embodiment, a single log charger 133 or a dual log charging system could be used to provide logs to the carriages 103, 104.
Yet a further embodiment contemplates a combination log and squared log ("cant") processor system whereby the teachings of the invention are applied to cants provided to the dogs from one side of the log charger and unprocessed logs are provided from the opposite side of the log charger. In this embodiment, cant yokes on the cant side of the log charger would position the cants for pickup but the dogs 129 would grasp and transport the logs and cants in a method identical to that taught by either the offset dog method or the reciprocating dual centre line log charger method described above.
The precise position of the roundway bearings 112 about the shafting 109 can be determined according to the loading on the carriages 103, 104. Bearings should be positioned both above and below the horizontal plane 148 (Figure 2A) and at least one bearing housing 110 should have bearings 112 on both sides of the vertical planes 149 passing through the shafting 109.
The log charger 133, although being described as useful for charging logs and/or cants from both sides of the charger 133 to the dogs 129 for loading in both of the carriage embodiments described, could, if desired, simply supply logs or cants from one side only.
Various other changes in the specific embodiments described are contemplated by the teachings herein and the description given should be taken as illustrative only and not as limiting the scope of the invention which should be construed in accordance with the accompanying claims.
In the endogging system preferably each of said carriage means 103, 104 reciprocates on rail means 109 and said carriages 103, 104 of each of said carriage means 103, 104 are separated, the distance between said separated carriages on said rail means 109 being adjustable.
- In the endogging system preferably each of said dog means 129 are connected to husk means 128 connected to said carriages 103, 104 and further comprising linkage means 114, 115 to extend said dog means 129 when grasping a log 136 at said first location and to retract said dogs 129 when releasing said log 136 at said second location.
In the endogging system preferably sensing means activates said linkage means 114, 115.
In the endogging system preferably said distance is adjustable by chain and pulley adjustment means 126.
In the endogging system preferably said distance is adjustable by a hydraulic cylinder adjustment means 143.
The method for transporting logs comprises offsetting the log grasping portions of said dog means 129 such that said vertical plane 116 generally passes through said log grasping portions of said dog means 129 when said log 136 is grasped.
In the bearing arrangement preferably said second bearing means 111 comprises a bearing housing 111 carrying roundway bearings 112 each of said bearing housings 110, 111 being located at a plurality of locations about and in contact with said first rail means 109.
In the bearing arrangement preferably one of said roundway bearings 112 in each bearing housing 110, 111 is mounted vertically above each respective rail means 109 and two of said roundway bearings 112 are mounted substantially symmetrically on opposite sides and below the centre line of each of said rail means 109.
In the endogging system preferably said charger means 133 is operable to provide a log 136 on said first vertical plane 146 to said dogs 129' of said first carriage means 103'.
In the endogging system preferably said first carriage means 103' is operable to transport a log 136 to said second location with said dogs 129' in said extended position and to pass said second carriage means 104' when said dogs 129' of said second carriage means 104' are in said retracted position.
In the endogging system preferably said first and second carriage means 103', 104' reciprocate substantially on said first and second vertical planes 146, 147 respectively.
In the log transport method preferably said first and second carriage means 103', 104' each move longitudinally substantially along a first and second vertical plane 146, 147 respectively, said first carriage means 103' moving from said first location to said second location with said first log while said second carriage means 104' is moving from said second location to said first location.
In the log transport method preferably said vertical planes 146, 147 are substantially parallel and are located relatively closely together.
In the log transport method preferably said first and second logs are provided at said first and second locations, respectively, by a log charger 133.
In the log transport method preferably said log charger 133 provides said first and second logs alternately between said first and second locations.
In the endogging system preferably said dog means 129 are retractable, said dog means 129 having a first extended position to transport logs and a second retracted position when said carriage means 103', 104' is not transporting logs.
In the endogging system preferably said log charger means 133is reciprocal between said first and second vertical planes 146, 147 and cooperates with said first and second carriage means 103¹, 104' to provide a log. alternately at said first and second vertical planes 146, 147, respectively.
In the log transport method preferably the steps of providing a first log at a first location, grasping said first log at said first location with a first set of dogs 129' extending from a first carriage means 103', transporting said log with said first carriage means 103' through a log processing station 140 substantially on a first vertical plane 146, releasing said log after passage through said log processing station 140 and returning said first carriage means 103' to said first location, providing a second log at a second location, grasping said second log with a second set of dogs 129' extending from a second carriage means 104' transporting said log through said log processing station 140 substantially on a second vertical plane 147, releasing said log after passage through said log processing station 140 and returning said second carriage means 104' to said second location, said log processing station 140 being alternately moveable between said first and second vertical planes 146, 147 to receive said logs from said first and second carriage means 103', 104' respectively.
In the log transport method preferably said vertical planes 146, 147 are substantially parallel and located relatively closely together.
In the log transport method preferably said first and second logs are provided at said first and second locations, respectively, by a log charger 133.
In the log transport method preferably said log charger 133 provides said first and second logs alternately between said first and second locations.

Claims

1. An endogging system comprising first and second carriage means (102, 103, 104) mounted on opposite sides of a vertical plane (116), each of said carriage means (103, 104) being operable to transport a log (136) from a first location located substantially on said vertical plane (116) to a second location and to return to said first location without said log (136) each of said carriage means (103, 104) having twin carriages, each of said carriages including dog means (129) extending downwardly therefrom, each of said dog means (129) being offset from said vertical plane (116) whereby said first and second carriage means (103, 104) may pass when said dog means (129) of said first carriage means (103) are in said transport mode and said dog means (129) of said second carriage means (104) are in said retracted mode.

2. An endogging system comprising first and second rail means (109) located on opposite sides of a vertical plane, a pair of carriages (102) on each of said rail means (109), each pair of said carriages being longitudinally separated on said rail means (109), husk (128) and dog (129) means connected to each of said carriages (103, 104), said dog means (109) being offset towards said vertical plane (116) and being retractable and extendible by linkages (130, 131) between said husk (128) and dog (129) means, each of said pair of carriages (102) being operable to reciprocate on its respective rail means (109) and to pass the other of said pair of carriages (102) when said dog means (129) on one of said pair of carriages (102) is retracted and said dog means (129) on the other of said pair of carriages (102) is extended.

3. A method of transporting logs from a first to a second location comprising the steps of grasping a first log (136) with dog means (129) of a first carriage means (103) in said first location, moving said log (136) with said first carriage means (103) to said second location while moving a second carriage means (104) and dog means (129) from said second location to said first location, releasing said first log (136) at said second location, grasping a second log with said dog means (129) of said second carriage means (104) at said first location, moving said second log with said second carriage means (104) to said second location, moving said first carriage means (103) to said first location, and releasing said second log at said second location.

4. The method of claim 3 and further comprising retracting said dog means (129) during said movement from said second to said first location.

5. The method of claim 4 and further comprising locating said first carriage (103) and dog means (129) on one side of a vertical plane (116) and locating said second carriage (104) and dog means (129) on the opposite side of said vertical plane (116).

6. A bearing arrangement for a log transport carriage means comprising a first and second rail means (109), a carriage means (102) reciprocal on said first and second rail means, first and second bearing means (110, 111) between said first and second rail means (109) and said carriage means (102), each of said bearing means (110, 111). being positioned about and in contact with each of said rail means (109) and being operable to transfer variable loading on said carriage means (102) to said rail means (109).

7. A bearing arrangement as in claim 6 wherein said first bearing means (110) comprises a pair of bearing housings (110) separated longitudinally on said rail means (109), each of said bearing housings (110, 111) carrying roundway bearings (112) located at a plurality of locations about and in contact with said second rail means (109).

8. A bearing arrangement for a log transporting carriage comprising a carriage means (102) reciprocally moveable on substantially horizontally located first and second rails (109), bearing means (110, 111) comprising a bearing housing (110, 111) and roundway bearings (112) mounted between each of said rails (109) and said carriage means (102), said roundway bearings (112) being mounted in said housing (110, 111) and above, below, and in contact with said rails (109) at a plurality of locations in each of said housings (110, 111), at least two of said bearing housings (110, 111) being mounted between said carriage means (102) and one of said rails (109).

9. An endogging system comprising log charger means (133), reciprocal first and second carriage means (103', 1O4'), each of said carriage means (103', 104') being operable to longitudinally transport a log (136) from said log charger means (133) to a second location along a first and second vertical plane (146, 147), respectively, dog means (129') mounted on each of said carriage means (103', 104') having an extended log transport and a retracted mode, said charger means (133) being alternately moveable between said first and second vertical planes (146, 147) to cooperate with the reciprocal movement of said carriage means (103', 104').

10. A log transport method comprising the steps of providing a first log at a first location with a log charger means (133), grasping said log at said first location with a first set of dogs (129) extending from a first carriage means (103), transporting said log with said first carriage means (103) through a log processing station (140), releasing said log after passage through said log processing station (140) and returning said first carriage means (103) to said first location, providing a second log at a second location with said log charger means (133), grasping said second log at said second location with a second set of dogs (129) extending from a second carriage means (104), transporting said second log through said log processing station (140), releasing said second log and returning said second carriage means (104) to said second location, said charger (133) alternately providing said first and second logs at said first and second locations, said first and second carriage means (103, 104) having reciprocating and oppositely opposed movement between said first and second locations and said log processing station (140).

11. An endogging system comprising log charger means (133), reciprocal first and second carriage means (103', 104'), each of said carriage means (103', 104') being operable to longitudinally transport a log from said log charger means (133) to a second location along the first and second vertical plane (146, 147), respectively, dog means (129') mounted on each of said carriage means (103', 104') and being operable to carry and transport logs, and log processing means (140) moveable between said first and second planes (146, 147) to receive a log transported by said first and second carriage means (103', 104'), respectively.