US3870090A

US3870090A - Arrangement in planing machines with feeding mechanism comprising at least two rollers

Info

Publication number: US3870090A
Application number: US342987A
Authority: US
Inventors: Morten Birger Hasfjord
Original assignee: SVENSKA IND TABLERINGS SVETAB
Current assignee: SVENSKA IND TABLERINGS SVETAB; SVENSKA INDUSTRIETABLERINGS (SVETAB) SWEDISH INDUSTRIAL ESTABLISHING Corp AB
Priority date: 1972-03-20
Filing date: 1973-03-20
Publication date: 1975-03-11
Anticipated expiration: 1992-03-11
Also published as: FR2176929A1; FR2176929B3; NL7303752A; SE357153B; IT983550B; DE2313054A1

Abstract

A feeding device for wood, especially for a planing machine, in which at least two feeding rollers are arranged above a feeding path for the wood and are adapted to be adjusted by a compression spring in conformity with the desired pressure the rollers are to exert upon wood on the feeding path. This compression spring acts between a first bearing located on a first support and an element displaceable in the direction of action of the compression spring in a second bearing which is located on another support, the bearings respectively being pivotable in their pertaining supports while an adjustable counter action device is operable to hold the rollers against the action of the compression spring when no wood is on the feeding path.

Description

Matte States Patent [191 Hasfjord 1 Mar. 11, 1975 ARRANGEMENT IN PLANING MACHINES WITH FEEDING MECHANISM COMPRISING AT LEAST TWO ROLLERS [75] Inventor: Morten Birger Hasfjord, Odeshog,

Sweden [73] Assignee: Svenska Industrietablerings AB (Svetab) Swedish Industrial Establishing Corporation, Stockholm, Sweden [22] Filed: Mar. 20, 1973 [21] Appl. N0.: 342,987

[30] Foreign Application Priority Data 8/1914 Garner .1 144/246 R Primary E.\aminerAndrew R. Juhasz Assistant ExaminerW. D. Bray Attorney, Agent, 01 Firm-Walter Becker [5 7] ABSTRACT A feeding device for wood, especially for a planing machine, in which at least two feeding rollers are arranged above a feeding path for the wood and are adapted to be adjusted by a compression spring in conformity with the desired pressure the rollers are to exert upon wood on the feeding path. This compression spring acts between a first bearing located on a first support and an element displaceable in the direction of action of the compression spring in a second bearing which is located on another support, the bearings respectively being pivotable in their pertaining supports while an adjustable counter action device is operable to hold the rollers against the action of the compression spring when no wood is on the feeding path.

8'Claims, 2 Drawing Figures UJJENTEU 1m 3. 870,09 0

1 ARRANGEMENT IN PLANING MACHINES WITH FEEDING MECHANISM COMPRISING AT LEAST TWO ROLLERS The present invention relates to an arrangement in planing machines with a feeding mechanism for wood, comprising one pair of feeding rollers being disposed above a feeding path for the wood and being supported in means, which are pivotable around a common pivoting axis disposed in parallel with the rotational axis of the feeding rollers, wherein meansare disposed to permit adjustment of the pressure of the feeding rollers against wood being transported on the feeding path in order to adapt said pressure to the thickness of the wood through swinging movement of the supporting means downwards around the common pivoting axis.

In conventional planing machines with floating upper rollers there is usually a spring system for each of the upper rollers. Such an arrangement has many drawbacks and disadvantages. A dismounting of the arrangement for changing worn rollers is very timeconsuming. If skidding occurs in the feeding operation there can be several different reasons therefore. Usually the operator understands the skidding as a result of too little pressure on the upper rollers but he does not know on which of the rollers the pressure should be increased. The skidding can also be dependent on too high pressure on one or both of the rollers, which causes the wood to be squeezed and clamped and results in the same problem as mentioned above in connection with too little pressure.

The object of the present invention is to provide an arrangement comprising simple and dismountable components, which permit arapid change of worn rollers.

Another object is to provide a simple method in attaining the same downwards directed pressure on the two upper rollers.

A still further object is to provide an apparatus containing cheap and rugged components.

These objects have been realized in an arrangement according to the invention which is substantially characterized in that said setting means comprise a compression spring device, which on that side of the common pivoting axis which faces away from the feeding path acts between one first. bearing means located at one support means and an element, which is displaceable in the direction of action of the compression spring device in a second bearing means, located at another supporting means, said bearing means being pivotable in corresponding supporting means around axes being disposed in parallel with the common pivoting axis and that an adjustable counter action device is arranged to hold the rollers against the action of the tension force when no wood is present on the feeding path.

By replacing the prior art system including a spring device for each upper roller, with a common pressure control device acting between the upper rollers, a very simple and easy dismountable design is provided, which enables an accurate setting of the roller pressure.

ln one embodiment of the invention, in which the points of action of the pressure control device on the two support means and the common pivot axis are located in the end points of the base line, and in the top point, respectively, of an isosceles triangle turned upside-down, one can easily make sure that the downwards directed pressures on the two upper rollers are equal. Thus, one single pressure control device is provided for the two upper rollers and a downwards directed force component on each of the upper rollers from each end of the device is attained, i.e., from the points of action of the device. If the distances between the centre of the pendulum axis and the axes of cylinder-shaped bearing elements, which are exerted to pressure in both ends of the arrangement are equal the two rollers will be exerted to equal pressures.

These objects and advantages, which will become subsequently apparent reside in the details of construction and operation as hereinafter described. reference being made to the accompanying drawing in which FIG. 1 is a side view of one part of the planing machine comprising a feeding mechanism for wood,

FIG. 2 is a detailed view, partly in section, showing one part of the feeding mechanism. 1

The planing machine, partly shown in side view in FIG. 1, comprises a machine frame 2. A feeding mechanism 4 being disposed at the supply end of the machine, comprises driven upper and

lower feeding rollers

6 and 8, respectively. The lower pair of feeding rollers is partly only indicated with dotted lines. The feeding rollers are operated by means of an electrical motor 9 via a chain transmission or the like in a manner neither shown nor described. Part of this transmission has been indicated in the block 10. After the feeding mechanism 4 the planing machine comprises conventional elements not disclosed such as undercutters, overcutters, sidecutters, a pressing mechanism and the like. 12 designates an undercutter. When the machine is operated wood is fed in a direction indicated by the arrow 14 between the pair of

feeding rollers

6 and 8, which are transporting the wood to be subject to the different working operations.

The upper portion of the feeding mechanism 4 will now be described more in detail. Each of the upper rollers 6 is rotatably journalled in a housing 16, which in its turn is pivoted on a common pivoting axis 18 in a frame part 20 between the two rollers 6. The driving shafts of the rollers 6 pass through vertically extended slots (not shown in the drawing) in a plate 22 being part of the machine frame 2. The chain transmission is mounted on the back of this plate. The vertically extended slots in the plate 22 permit some swinging movement of the housings 16' and thus the rollers 6 around the pivot axis 18. On the upper side each of the housings 16 is provided with a fork like projection 24. A pressure device 26 with controllable tension, in this embodiment a spring device, acts between these projections and operates in such a manner that it tends to press the two projections 24 apart from each other. The action from the spring device 26 on the housing 16 is counteracted by a vertical support pin 28, which rests with its lower end on the support 30. The support pins 28 are partly provided with threads 32. The support pin 28 is thus screwed through a threaded bore in a portion rigidly connected with the corresponding housing on the inside of said housing, as indicated with reference numeral 34 for the left housing in FIG. 1. The support pin 28 can be located in a certain position relative to the corresponding housing 16 by means of a faucet, not disclosed, which is screwed into engagement with the support pins through the housing. The faucet is operated by means of a handle 36. Each of the support pins 28 is screwed by means of a hand wheel 38.

The spring device designated with reference numeral 26 is shown more in detail in FIG. 2. The fork-like projections 24 of the housings 16 are provided with halfcylindrical recesses 40 in the two legs on the two surfaces facing each other. The recess 40 in the fork-like projection ofthe right housing 16 serves as hearing seat for a cylindrical bearing element 42, which is in contact with the two legs. The projection 40 on the left side serves as a seat for a bearing element 44 formed substantially in the same way. The bearing element 42 includes the threaded bore while the bearing element 44 is provided with a smoothed bore. The two bearing elements 42 and 44 are supporting a rod 46, which with a threaded part 48 is screwed through the bearing element 42 and with a smoothed part 50 is slidably passed through the bearing element 44 and thereby simultaneously passes between the fork-like projections. The rod 46 is provided with one stop 52. Another stop 54 is connected to the bearing element 44. The two stops 52 and 54 serve as seats for the ends of a compression spring 56. A hand operated crank 58 is mounted in the threaded end of the rod 46. The contact pressure of the feeding rollers towards a deal fed between the rollers in the direction of the arrow 14 is determined by means of the spring device 26 (elements 48-58) and the value of the pressure can be accuratly set by means of ascale (not shown) showing the rotational position of the rod 46. The support pins 28 support the rollers 6 and their housings 16 through the contact against the support 30 when no wood is located between the

feeding rollers

6 and 8 and when wood is introduced the support pins 32 are somewhat lifted up from their supports 30. The support pins 32 also serve to keep the

feeding rollers

6 and 8 at such a distance from each other that the introduction of wood between the rollers will be easily effected.

The complete spring arrangement 26, comprising the elements 40-58, can be easily dismounted from the position shown, by turning the rod 46 counterclockwise by means of the crank until the bearing elements 42, 44 loose contact with their bearing sets and permit the whole arrangement to be lifted up. This operation takes only a few minutes and the rollers 6 are then easy to dismount.

in the embodiment shown the rotational axes of the two bearing elements 42, 44 relative to the corresponding support means 16 and the axis 18 are located in the end points of a base line or in the top point of an isosceles triangle, respectively. This arrangement provides the advantage that the pressure on the two rollers will be equal.

The pressure device disclosed comprises a coil spring but it is of course possible to replace it with some other element providing the same or equivalent effect, for instance a hydraulic oil cylinder.

I claim:

1. An arrangement in a planing machine with a feeding mechanism for wood, comprising a pair of feeding rollers disposed on one side of a feeding path for the wood each roller being supported by a supporting means, both said supporting means being pivotable around a common pivot axis disposed in parallel direction with the rotational axes of the feeding rollers, said feeding rollers having pressure adjustment means associated therewith for setting the pressure of the feeding rollers against wood fed on the feeding path in order to adapt said pressure to the thickness of the wood through swinging movement of said supporting means downwards around the common pivot axis, characterized in that said pressure adjustment means comprises a compression spring device located on the side of the common pivot axis facing away from the feeding path and acting between a first bearing means located at one of said supporting means and a pressure controlling element displaceable in the direction of action of the compression spring device in a second bearing means located at the other supporting means, both of said bearing means being pivotable in the corresponding supporting means around a corresponding axis extending in parallel direction with said common pivot axis, an adjustable counter action device being arranged to hold the rollers against the action of the spring tension force when no wood is present on the feeding path.

2. An arrangement according to claim 1, characterized in that the compression spring device comprises a helical compression spring acting between said first bearing means and a stop located on a threaded bar forming said pressure controlling element, said bar extending through and in threaded engagement with said second bearing means in alignment with the spring.

3. An arrangement according to claim 2, characterized in that said threaded bar extends through the entire length of the spring and forms a guiding means for said first bearing means at the end of said spring facing away from the stop, said first bearing means being freely slidable on the rod.

4. An arrangement according to claim 1, characterized in that the displacement of said pressure controlling element in said second bearing means and thus the spring device tension is adjustable by means of a calibrated setting device.

5. An arrangement according to claim 1, characterized in that the counter-action device comprises screws screwed through each of said supporting means, said screws cooperating with a rigid stop in the machine frame.

6. In a planing machine for planing wood, a frame structure; a feeding path for said wood; a pair of lever means pivotally supported in said frame structure around a common pivot axis extending transversely to said feeding path in a plane parallel thereto, each lever means rotatably supporting a corresponding wood feeding roller around a rotational axis extending in parallel to said common pivot axis, a pair of arm means rigidly connected to one of said lever means each and extending away from said feeding path, each arm means having a bearing element rotatably supported around a rotational axis parallel to said pivot axis, a bar extending in parallel to said feeding path through said bearing elements, said bar being threadedly engaged with one of said bearing elements and freely movable in its longitudinal direction through the other bearing element, a helical compression spring extending around said bar between a first stop on said bar at said other bearing element and a second stop on said bar between said bearing elements, means for rotating said bar; means for supporting said lever means against the action of said helical spring when there is no wood present on said feeding path.

7. The arrangement according to claim 6, wherein each lever means carries a roller cover rotatably supporting a rotational shaft for the corresponding wood feeding roller and carrying a corresponding one of said arms means, said means for supporting said lever means against the action of said helical spring compris- 6 the rotational axes of the two bearing elements and said common pivot axis are located in the end points of the base line and in the top point of an isosceles triangle, respectively.

Claims

7. The arrangement according to claim 6, wherein each lever means carries a roller cover rotatably supporting a rotational shaft for the corresponding wood feeding roller and carrying a corresponding one of said arms means, said means for supporting said lever means against the action of said helical spring comprising at each of said covers a threaded support rod extending through a correspondingly threaded hole in the cover towards said feeding path, the end of said rod turned towards the feeding path abutting against a stop in said frame structure.