Planer head

A planer head includes a cylindrical body having a first end, a second end and a crenelated curved face extending therebetween and including a plurality of pockets receiving a plurality of knives and knife holders. A clamping assembly connects each of the plurality of knife holders to their corresponding knives by frictional engagement. The clamping assembly includes at least one pair of clamping elements, each being disposed on a corresponding one of the first and second ends of the body. When moved in the longitudinal direction toward each other, the at least one pair of clamping elements forcing the plurality of knife holders in the radial direction thereby engaging in friction the knife holders with their corresponding knives and knife pockets of the body. A number of pairs of clamping elements is lower than a number of at least one of knives and knife holders. A kit for a planer head assembly, a clamping assembly, and a planer body are also presented.

BACKGROUND

To manufacture plain wood lumbers, freshly cut wood logs undergo a series of transformations. Typically, the bark is first removed, then the cross-section of the wood log is transformed from a rounded shape to a cruciform shape. This shape transformation optimizes the number of wood lumbers that can be extracted from a given wood log. In a further step, wood lumbers are cut out of each of the cruciform shaped wood logs, and finally, the surfaces of the wood lumbers are trimmed to reduce roughness and splinters, and to obtain a consistent thickness throughout the length of the lumber.

The trimming step is generally carried out using one of more planer heads. A planer head has the general configuration of a large rotating wheel provided with a plurality of knives extending outwardly from its circumference. When a lumber passes about a planer head in rotation, the knives take off an outside layer of the wood lumber (typically a ¼ or ½ inch layer) thereby trimming and smoothing its surface. An example of a planer head10of the prior art is shown inFIGS. 1 to 3. In this prior art configuration, the planer head10includes a generally cylindrical body12having a centrally disposed bore14coinciding with an axis of rotation R1of the planer head10(which is also its longitudinal axis). The body12is plain and typically made of machined steel. The body12includes a plurality of knife pockets16(best shown inFIG. 2) radially disposed and uniformly distributed on a crenelated curved face18defining the circumference of the body12, as best shown inFIG. 2.

The knife pockets16each includes a first wall15, and a second wall17spaced apart and opposing the first wall15. The first wall15can be scalloped, while the second wall17is substantially flat. Each of the knife pockets16is configured to receive a corresponding knife20(only one knife20being drawn in the figures) and a knife holder22for holding the knife20into position during the operation of the planer head10.

Each knife20includes a connection portion24receivable in a knife pocket16to connect to the body12, and a cutting edge26extending from the connection portion24to trim the wood lumbers when the planer head10is rotated about the axis of rotation R1.

Knife holders22are typically longitudinal slender members that collaborate with clamping assemblies30to retain the knives20onto the body12, where each knife holder22is operated by a corresponding one of the clamping assemblies30(best shown inFIG. 3).

As it will be appreciated by those skilled in the art, this planer head configuration suffers many drawbacks. The clamping assemblies30are independent of each other, and each knife holders22is operated by its unique and corresponding clamping assemblies30. As such, when knives20must be installed, replaced or repositioned, the operations have to be repeated for each and every one of the clamping assemblies30, which tends to make the replacement of the knives20burdensome and costly. Further, because each of the knife20is adjusted independently, they may not protrude radially from the pocket16equally, which may cause ovalization of the planer head10.

In other examples of prior art planer heads, the clamping assemblies may be disposed somewhere else on the planer head, but still require a plurality of knife holders and a corresponding plurality of clamping or securing mechanism, which makes the maintenance of such planer heads cumbersome.

Therefore, there is a need for a planer head that will overcome at least one of the above-identified drawbacks.

BRIEF SUMMARY

According to a broad aspect of an embodiment of the present invention, there is provided a planer head comprising a generally cylindrical body including a first circular end, a second circular end and a crenelated curved face extending therebetween. The cylindrical body further includes a longitudinal rotation axis extending between the first circular end and the second circular end, and at least two knife pockets defined on the crenelated curved face and uniformly spaced-apart from one another. Each knife pocket includes a first wall and second wall, each pair of adjacent knife pockets defining a radially projecting knife retaining member therebetween. The planer head also comprises at least two knife holders, each knife holder being received in a corresponding knife pocket and being movable radially therein between a lower position and an upper position, each knife holder having first and second walls, the first wall of each knife holder being adjacent to the first wall of the knife pocket. The planer head also comprises at least two knives, each knife having a connection portion received in a corresponding knife pocket between the second wall of the knife holder and the second wall of the knife pocket, and a cutting portion extending from the connection portion and projecting radially from the crenelated curved face of the cylindrical body. According to this broad aspect, the planer head further comprises a clamping assembly including first and second clamping members mounted to the first and second circular ends of the cylindrical body and movable along the longitudinal rotation axis between a distal position and a proximal position, as well as a securing means for mounting the first and second clamping members to the first and second circular ends of the body and urging the first and second clamping members toward one another in the proximal position. When the first and second clamping members are in the distal position, the at least two knife holders are in the lower position thereby permitting movement of the at least two knives in the corresponding knife pockets while when the first and second clamping members are in the proximal position, they urge the at least two knife holders in the upper position thereby securing the at least two knifes in the corresponding at least two knife pockets.

According to another broad aspect of an embodiment, there is provided a kit of a planer head assembly. In this broad aspect, the kit comprises a generally cylindrical body including a first circular end, a second circular end and a crenelated curved face extending therebetween. The cylindrical body further includes a longitudinal rotation axis extending between the first circular end and the second circular end, and at least two knife pockets defined on the crenelated curved face and uniformly spaced-apart from one another. Each knife pocket includes a first wall and second wall, each pair of adjacent knife pockets defining a radially projecting knife retaining member therebetween. The kit also comprises at least two knife holders, each knife holder being receivable in a corresponding knife pocket and being movable radially therein between a lower position and an upper position, each knife holder having first and second walls, the first wall of each knife holder being adjacent to the first wall of the knife pocket when the cutter head is assembled, and at least two knives. Each knife has a connection portion receivable in a corresponding knife pocket between the second wall of the knife holder and the second wall of the knife pocket, and a cutting portion extending from the connection portion and projecting radially from the crenelated curved face of the cylindrical body when the cutter head is assembled. The kit further comprises a clamping assembly including first and second clamping members mountable to the first and second circular ends of the cylindrical body and movable along the longitudinal rotation axis between a distal position and a proximal position, and a securing means for mounting the first and second clamping members to the first and second circular ends of the body and urging the first and second clamping members toward one another in the proximal position. When the first and second clamping members are in the distal position, the at least two knife holders are in the lower position thereby permitting movement of the at least two knives in the corresponding knife pockets while when the first and second clamping members are in the proximal position, they urge the at least two knife holders in the upper position, thereby securing the at least two knifes in the corresponding knife pockets.

In an additional feature, the cylindrical body further comprises a bore extending between the first end to the second end for mounting the body to a rotating shaft.

In yet an additional feature, each of the at least two knife pockets extends longitudinally between the first end and the second end of the cylindrical body.

In still an additional feature, the first and second walls of each of the at least two knife pockets converge toward one another to define a funnel shape. Preferably, the first and second walls of each of the at least two knife holders also converge toward one another, to define a generally tapering cross-section.

In a further feature, the planer head comprises between 20 and 40 knife pockets and a corresponding number of knives and knife holders, and preferably 36 knife pockets and a corresponding number of knives and knife holders.

In another feature, the cylindrical body further comprises a first annular recess on the first circular end and a second annular recess on the second circular end. The first and second clamping members respectively comprise first and second annular rings at least partially engaged in the corresponding first and second recesses, the first and second annular rings engaging the at least two knife holders and urging the same in the upper position. Preferably, each of the first and second rings comprises an outer annular face, an inner annular face, a curved inner face and a beveled, curved outer face extending between the outer and inner annular faces. The beveled curved outer faces of the first and second annular rings engage the at least two knife holders and urge the same in the upper position. Still preferably, each of the at least two knife holders comprises first and second beveled faces, the first and second beveled faces of the at least two knife holders collaborating with the beveled curved outer faces of the first and second annular rings for urging the at least two knife holders in the upper position.

In an additional feature, the cylindrical body comprises a plurality of bores extending between the first and second circular ends and the first and second annular rings comprise a corresponding plurality of holes extending between the outer and inner annular faces thereof. In this additional feature, the fastening means of the clamping assembly comprises a corresponding plurality of bolts and nuts, each bolt being received in a corresponding bore of the cylindrical body and in corresponding holes in the first and second rings, the plurality of bolts and nuts urging the first and second rings to engage at least partially the first and second recesses the first and second rings to engage the at least two knife holders and urging the same in the upper position.

In still another feature, each of the first and second annular recesses of the cylindrical body comprises a threaded inner curved face. In this feature, the fastening means includes first and second annular fasteners and each annular fastener comprising an inner threaded curved face engaging the threaded inner curved faces of the cylindrical body and an inner annular face engaging the outer annular face of a corresponding ring. The fastening of the first and second annular fasteners engages the first and second rings at least partially in the corresponding recesses to engage the at least two knife holders and urging the same in the upper position.

In a further feature, first and second clamping members each comprises a plurality of segments, the plurality of segments defining together an annular ring.

According to yet another broad aspect of an embodiment, there is provided a clamping assembly for a planer head including a generally cylindrical body having at least two knife pockets, at least two knife holders and at least two knives receivable in the at least two knife pockets. In this broad aspect, the clamping assembly comprises first and second clamping members mountable to first and second circular ends of the cylindrical body and movable along a longitudinal rotation axis between a distal position and a proximal position, and a securing means for mounting the first and second clamping members to the first and second circular ends of the body and urging the first and second clamping members toward one another in the proximal position. When the first and second clamping members are in the distal position, the at least two knife holders are in a lower position in the knife pockets thereby permitting movement of the at least two knives in the knife pockets while when the first and second clamping members are in the proximal position, they urge the at least two knife holders in an upper position thereby securing the at least two knifes in the corresponding at least two knife pockets.

According to another broad aspect of an embodiment, there is provided a cylindrical body for a planer head. The cylindrical body comprises a first circular end, a second circular end and a crenelated curved face extending the first circular end and the second circular end. The cylindrical body also comprises a longitudinal rotation axis extending between the first circular end and the second circular end, and at least two knife pockets defined on the crenelated curved face and uniformly spaced-apart from one another. Each knife pocket includes a first wall and second wall, each pair of adjacent knife pockets defining a radially projecting knife retaining member therebetween. Each of the at least two knife pockets is configured to receive a knife holder and allowing movement of same in a radial direction between a lower position and an upper position, each knife holder having first and second walls, the first wall of each knife holder being adjacent to the first wall of the knife pocket and a connection portion of a knife. In this broad aspect, the cylindrical body is configured to receive a clamping assembly including first and second clamping members mountable to the first and circular second ends of the cylindrical body and movable along the longitudinal rotation axis between a distal position and a proximal position, and a securing means for mounting the first and second clamping members to the first and second circular ends of the cylindrical body and urging the first and second clamping members toward one another in the proximal position. When the first and second clamping members are in the distal position, the at least two knife holders are in the lower position thereby permitting movement of the at least two knives in the corresponding knife pockets while when the first and second clamping members are in the proximal position, they urge the at least two knife holders in the upper position thereby securing the at least two knifes in the corresponding at least two knife pockets.

Embodiments of the present can have at least one of the above-mentioned aspects, but do not necessarily have all of them.

Additional and/or alternative features, aspects, and advantages of embodiments of the present will become apparent from the following description, the accompanying drawings, and the appended claims.

DETAILED DESCRIPTION

Referring toFIGS. 4 to 21, a first embodiment of a planer head100will be described. In this embodiment, the planer head100includes a body102, a plurality of knives104, a corresponding plurality of knife holders106and a clamping assembly108(best shown inFIGS. 6 and 14), which collaborate with the knife holders106for securing knives104to the body102(only some knives104and knife holders106being identified with reference numerals). In the illustrated embodiment, the planer head100includes 36 knives104and 36 knife holders106. It is however contemplated that the planer head100could comprise a different number of knives104and corresponding knife holders106. For instance, the planer head100could comprise two or more knives104and knife holders106. In one embodiment, the planer head100could comprise between 10 and 60 knives104and knife holders106, and preferably between 20 and 40 knives104and knife holders106.

With reference toFIGS. 8 to 10, the body102is generally cylindrical and has a generally circular right end110, a generally circular left end112and a crenelated curved face114extending between the right end110and the left end112and defining the circumference of the body102. The body102is preferably made of machined steel. The body102has a centrally disposed bore116extending between the right end110and the left end112for mounting the planer head100on a rotating shaft (not shown), for rotation about an axis of rotation R2.

The body102includes a plurality of knife pockets118disposed on the curved face114(best shown inFIG. 9). In the embodiment shown, the body includes 36 knife pockets118. The person skilled in the art will appreciate that the number of knife pockets118could be different, and that the number of such knife pockets118will define the number of knives104and knife holders106mountable to the body102. The knife pockets118are uniformly spaced apart (i.e. distributed) along the crenelated curved face114or circumference of the body102.

Each knife pocket118is sized and shaped to receive a corresponding knife104and a corresponding knife holder106therein. Each knife pocket comprises a lower receiving portion120and an upper receiving portion122(best shown inFIG. 9). The lower and upper receiving portions120,122share a common front wall124, which is forwardly angled at an angle θ1relative to a radius extending from the rotation axis R2to the bottom end129of the front wall124(seeFIG. 8). At the top end125of the front wall124is defined a recess127for retaining a knife holder106received in the knife pocket118, as it will be described in greater detail below. The lower receiving portion120is also provided with a back wall126, spaced apart from the front wall124and extending parallel thereto, as well as a bottom wall128extending between the front wall124and the back wall126and perpendicular thereto, at the bottom ends129,131thereof.

The upper receiving portion122of the knife pocket118comprises a back wall130having a top end132and a bottom end134. The back wall130is forwardly angled at an angle θ2relative to a radius extending from the rotation axis R2to the bottom end134. As one can appreciate fromFIG. 8, the angle θ2is larger than the angle θ1, and therefore the top end132of the back wall130converges toward the front wall124, at an angle θ3, to define somewhat of a funneled shaped knife pocket118(seeFIG. 9). While in the illustrated embodiment, the front and back walls124,126and130are generally flat, it is contemplated that in an alternative embodiment at least one of them could be scalloped to increase frictional engagement with the knife104and knife holder106.

Extending between the bottom end134of the back wall130and the bottom end131of the back wall126of the lower receiving portion120is an knife resting wall136. The knife resting wall136extends perpendicular to the back wall130and provides support to the knife104received in the knife pocket118, as it will become apparent below.

As it will be appreciated, a portion of the body102extends generally radially between each pair of adjacent knife pockets118. Together, the knife pockets118therefore define a plurality of knife retaining members138, each retaining member138comprising a trailing face140(corresponding to the front wall124of a first knife pocket118), a leading face142(corresponding to the back walls126and130of the adjacent knife pocket118) and a forwardly and upwardly angled top face144extending between the trailing face140and the leading face142. Each knife retaining member138also includes lower portion146extending from the bottom wall128of the lower portion120to a junction J1corresponding to the junction between the upper end133of the back wall126and the knife resting wall136, as well as an upper portion148extending from the junction J1to the top face144of the retaining member138.

Returning toFIGS. 6 and 7, a right annular recess150is defined on the right end110of the body102for receiving a portion of the clamping assembly108. Likewise, the left end112of the body102is provided with a left annular recess152for receiving another portion of the clamping assembly108, as it will be described in greater detail below. As best shown inFIG. 10, the right annular recess150comprises a lower curved face154extending longitudinally (i.e. parallel to the rotation axis R2) and an annular right face156extending radially and perpendicularly to the lower curved face154. The right annular recess150also comprises an upper curved face158defined on the lower portion146of the knife retaining members138, the upper curved face158extending from the annular right face156to the junction J1. As best shown inFIG. 10, the upper curved face158is gently curved outwardly to smoothly transition from the radial orientation of the angular right face156(i.e. perpendicular to the rotation axis R2) to a longitudinal orientation (i.e. parallel to the rotation axis R2). The left annular recess152is merely a mirror image of the right annular recess150. As such, the description of the right annular recess150applies to the left annular recess152, with proper adaptation. As it will be apparent fromFIG. 10, the right and left annular recesses150,152cause the knife retaining members138to define somewhat of a T-shape, where the lower portion146of the knife retaining member138has a width W1and the upper portion148has a wider width W2.

Defined in the right and left annular recesses150,152and extending longitudinally between the right and left ends110,112is a plurality of bores160for receiving a corresponding plurality of fasteners162used to secure the clamping assembly108, as it will become apparent below.

Turning now toFIGS. 11A to 11C, the knife holders106will be described in accordance with one embodiment. In this embodiment, each knife holder106has a longitudinal oriented slender body having a right end164and a left end166. The knife holder106further comprises a lower portion168sized and shaped to be received in the lower receiving portion120of a knife pocket118, and an upper portion170, sized and shaped to be received in the upper receiving portion122of the corresponding knife pocket118. The lower and upper portions168,170of the knife holder106share a common leading face172configured to abut the front wall124of the knife pocket118. The lower portion168of the knife pocket also comprises a trailing face174, parallel to the leading face172, and a bottom face176extending between the leading face172and the trailing face174, perpendicular thereto. The upper portion170also comprises a trailing face178, extending at an angle θ4relative to the leading face172. Extending between the lower end of the trailing face178of the upper portion170and the trailing face174of the lower portion168is an intermediate face180. Extending between the trailing face178of the upper portion170, and the leading face172, at the upper end thereof, is a curved top face182terminating in a forwardly extending lip184, sized and shaped to be received in the recess127of the knife pocket118.

The lower portion168and the upper portion170of the knife holder106meet at a junction J2(shown inFIG. 11A). As best shown inFIG. 12, the bottom face176has a width W3corresponding to width W1of the knife retaining member138, at the upper portion148thereof, while the upper portion170of the knife holder106has a width W4corresponding to the width W2of the knife retaining member138, at the upper portion148thereof. As such, beveled right and left faces186,188extend from the bottom face176to the junction J2.

As it can be seen inFIG. 12, the beveled right and left faces186,188extend or project into the recesses150and152absent the clamping assembly108. As it will become apparent below, these beveled right and left faces186,188collaborate with the clamping assembly108to force the knife holder106in a radially outward position, thereby securing the knife104in the knife pocket118by frictional engagement. In one embodiment, each knife holder106is made of machined iron tool steel. The skilled addressee will appreciate that various alternative embodiments may be provided.

With reference toFIGS. 13A and 13B, each knife104has the general shape of a rectangular plate and comprises a connection portion190receivable in a corresponding knife pocket118and a cutting portion192extending therefrom. Each knife104has a right end194, a left end196, as well as a leading face198and a parallel trailing face200extending therebetween. Extending perpendicularly to the leading and trailing faces198,200, at the lower end thereof, is a bottom face202, while a top face204extends angularly (upwardly and forwardly) from the upper end of the trailing face200toward the upper end of the leading face198to define a cutting edge206. The knife104has a width W5corresponding to the width W2of the knife retaining member138. In one embodiment, each knife104is made of machined iron tool steel. The skilled addressee will appreciated that various alternative embodiments may be provided.

When the knife104is positioned in the knife pocket118(best shown inFIGS. 21A and 21B), the connection portion190is received in the knife pocket118, and the cutting edge206extends outwardly from the body102. The cutting edges206of the knives104are disposed so that they face a same forward direction to effectively cut an outside layer of the wood lumbers (not shown) when the planer head100is rotated about the axis R2.

Contrary to the systems of the prior art, for which an example has been described above with respect toFIGS. 1 to 3, the planer head100includes a single clamping assembly108to simultaneously secure all the knives104to the body102, via the knife holders106. In the embodiment shown inFIGS. 4 to 21, the clamping assembly108comprises a right clamping sub-assembly including a right ring208sized and shaped to be received in the right annular recess150of the body102, a left clamping sub-assembly including a left ring210sized and shaped to be received in the left annular recess152of the body102and the plurality of fasteners162receivable in the bores160for securing the right and left rings208,210to the body102and securing the knives104to the body102, via the knife holders106.

As best shown inFIGS. 14 and 15, the right ring208comprises an outer annular face212having a width W6, an inner annular face214having a narrower width W7and a first curved face216defining an inner diameter D1of the ring208and extending perpendicular to the outer and inner annular faces212,214(i.e. longitudinally or parallel to the rotation axis R2). The right ring208also comprises a second, beveled face218extending between the outer and inner annular faces212,214. Defined on the second, beveled face218is a recess220, in which is received a ring or dampener222(best shown inFIGS. 16 and 20B) to improve sealing and reduce vibrations when the right ring208is installed and the planer head100is operated. In one embodiment, the dampener222is made of a rubber material, for instance a nitrile synthetic rubber. In the illustrated embodiment, the right ring208has a thickness T1, defined between the outer annular face212and the inner annular face214, which is slightly less than a depth d1of the right annular recess150(shown inFIG. 16). Defined in the right ring208is a plurality of flanged holes224. The flanged holes224are distributed on the right ring208to be in alignment with the bores160of the body102when the right ring208is properly positioned in the right recess150. Further, the flanged holes224are sized and shaped to allow the passage of a portion of the fasteners162while providing an abutment area or flange223for another portion of the fasteners162. In the illustrated embodiment, the flanged holes224are generally circular, but other hole shapes are contemplated.

Likewise, the left ring210comprises an outer annular face226having a width W6, an inner annular face228having a narrower width W7and a first curved face230defining an inner diameter D1of the ring210and extending perpendicular to the outer and inner annular faces226,228(i.e. longitudinal or parallel to the rotation axis R2). The right ring210also comprises a second, beveled face232extending between the outer and inner annular faces226,228. Defined on the second, beveled face232is a recess234, in which is received a ring or dampener236similar to dampener222. In the illustrated embodiment, the right ring210has a thickness T2, defined between the outer annular face226and the inner annular face228, which is slightly less than a depth d2of the left annular recess152(shown inFIG. 16). It will be understood the thicknesses T1and T2of the rings208and210could be larger than the depths d1and d2of the right and left annular recesses150,152and yet, allow achieving the purpose of the embodiment. In this case, the rings208,210would engage the recesses150,152only partially rather than completely, as illustrated inFIG. 16.

Defined in the right ring210is a plurality of flanged holes238. The flanged holes238are distributed on the right ring210to be in alignment with the bores160of the body102and the holes224of the right ring208when right and left rings210are properly positioned in the right recesses150and152, respectively. The flanged holes238are sized and shaped to allow the passage of a portion of the fasteners162while providing an abutment area or flange239for another portion of the fasteners162, and to receive a locking assembly240for locking the fastener162, as it will become apparent below. In the illustrated embodiment, the flanged holes238have a key shape, but it will be understood that other shapes of flanged holes238are contemplated.

As it can be seen inFIG. 16, the first curved face216of the right ring208adjoins the lower curved face154of the right recess150when the ring208is in position in the right recess150, while the inner annular face214of the right ring208extends along the annular right face156, parallel thereto. Likewise, the first curved face230of the left ring210adjoins the lower curved face154of the left recess152when the ring210is in position in the left recess152, while the inner annular face226of the left ring210extends along the annular left face156, parallel thereto. In one embodiment, the right and left rings208,201are made of steel. The skilled addressee will appreciate that various alternative embodiments may be possible.

The fasteners162are used to secure the right and left rings208,210to the body102. In the illustrated embodiment, each fastener162comprises a bolt250having a head252and an elongated portion254provided with a threaded portion256, and a nut258engaging the threaded portion256. Each bolt250is adapted to extend through a corresponding flanged hole224of the right ring208, the head252resting against the flange223of the flanged hole224, through a corresponding hole160in the body102and then through a corresponding flanged hole238in the left ring210. The nut258is receivable in the key-shaped flanged hole238of the left ring210to engage the threaded portion256of the corresponding bolt250. As it will be appreciated, the screwing of the nuts bolts250and nuts258forces the right and left rings208,210toward one another, thereby causing the right and left rings208,210to engage the right and left recesses150,152, respectively. Although in the illustrated embodiment, the planer head100comprises 8 fasteners162, it will be understood that a different number of fasteners is contemplated. As it will be understood however, the number of fastener162to secure is greatly reduced as compared to the number of clamping assemblies of the prior art planer head configurations (e.g. the clamping assembly30shown inFIG. 3). The skilled addressee will appreciate that various alternative embodiments may be possible.

As best seen inFIGS. 16 and 17, each fasteners162further includes a locking assembly240. The locking assembly240is designed to restrict motion of the nut258should it become undone or loose due to vibration and centrifugal forces exerted during rotation of the planer head100. In one embodiment, the locking assembly240comprises a star-shaped washer262integrally formed with the nut258, and a spring loaded push rod assembly264mounted onto the flange239of the key-shaped flanged hole238. The push rod assembly264includes a push rod266slidably engaged in a sleeve268, the sleeve268being fixedly mounted to the flange239of the key-shaped hole238defined in the left ring210by a pair of screws270. The push rod266is disposed laterally from the nut258so that the push rod266abuts a recess of the star-shaped washer262. As the push rod assembly264is spring loaded, a force is exerted onto the nut258to prevent unwanted rotation or unscrewing thereof. It is contemplated that the washer262of the nut258could be shaped differently (i.e. having a shape other than a star shape), provided that the nut258includes at least one recess engageable by the push rod266. It is also contemplated that the locking assembly240could be designed differently. For example, the locking assembly240could include a hinge lock or caps and locking fasteners. It is also contemplated that the locking assembly240could be omitted. The skilled addressee will appreciate that various alternative embodiments may be possible.

In the illustrated embodiment, the clamping assembly108is further provided with a plurality of springs270(best shown inFIGS. 14 and 16), designed to be sandwiched between the right and left rings208,210and the annular faces156of the recesses150,152, respectively. Springs270are associated with corresponding fasteners162and are aimed at facilitating the extraction of the right and left rings208,210from the right and left recesses150,152, when the fasteners162are removed. As it will be appreciated the springs270could be omitted. The skilled addressee will appreciate that various alternative embodiments may be possible.

Turning now toFIGS. 18 to 21B, the assembly of the planer head100now will be described. In a first step, knives104and knife holders106are positioned in the knife pockets118, one knife104and one knife holder106being received in a corresponding knife pocket118. At this stage, the knife104and the knife holder106are relatively loose in the knife pocket118(best shown inFIG. 21A), therefore allowing alignment of the right and left ends194,196of the knife104and knife holder106with the right and left ends110,112of the planer head body102. Further, the beveled faces186,188of the knife holders106extend in the right and left recesses150,152, as described above (seeFIG. 12).

The bolts250are then partially engaged in the flanged holes224of the right ring208, and springs270are positioned along the elongated portion254of the bolts250until they abut the inner annular face214of the right ring208. The threaded portion256of the bolts250is then engaged in the corresponding holes160of the planer head body102, and the right ring208is pushed towards the body102until it partially engages the right recess150and the threaded portion256of the bolts250protrude outwardly from the annular face156of the left recess152.

At this time, additional springs270are positioned onto the protruding portion of the bolts250(i.e. corresponding to the threaded portion256), and the left ring210is positioned thereon. More specifically, the threaded portion256of each bolt250is engaged through a corresponding key-shaped flanged hole238of the left ring210, and the left right210is pushed towards the body102until the left ring210partially engages the left recess152. The nuts258are then engaged onto the threaded portion256of the bolts250, the push rod assemblies264being disengaged from the star-shaped washers262to allow screwing of the nuts258. At this time, the left and ring rings208,210are in a distal position relative to one another and the knives104and knife holders106are still relatively loose in the knife pockets.

As the nuts258are screwed onto the bolts250, the head252of the bolts250and the nuts258abut against the flanges223,239of the corresponding flanged holes224,238, thereby forcing the right and left rings208,210to move toward one another, in a proximal position. As the rings208,210move towards one another, they gradually engage the corresponding recesses150,152of the body102. As it will be appreciated, the nuts258are preferably screwed in a manner that will allow a gradual and uniform longitudinal movement along the circumference of the rings208,210such that the rings208,210do not become misaligned with respect to the corresponding recesses150,152.

As the rings208,210move into the recesses150,152, the beveled faces218,232of the rings208,210engage the beveled faces186,188of the knife holders106, and force the knife holders106in a radially outward position. At this stage, the clamping assembly108is in a proximal position (which corresponds to the operation position of the clamping assembly108) and the bottom face202of each knife104lies against the knife resting wall136of a corresponding knife pocket118. As the knife holders106move outwardly, the funneled shape of the pockets118and the tapering shape of the knife holders106collaborate to push the knife holders106against the knives104, the trailing face176of the upper portion170of each knife holder106engaging the leading face198of a corresponding knife104. As the rings208,210move further toward one another in the recesses150,152, the knife holders106and the leading faces142of the knife retaining members138collaborate to frictionally engage the knife104and simultaneously secure all the knives104. At this point, the planer head100can be operated. In some embodiments, protective annular plates113,115(shown inFIGS. 4 to 6 and 20A) can be secured to the assembled planer head100to protect the ends110,112from wear and damage.

While in the above-described embodiment the leading and trailing faces198,200,172,174,178,140and142of the knives104, knife holders106and knife retaining members138are generally flat, it is contemplate that at least some of them could be scalloped to increase frictional engagement. Further, although the planer head100is being described herein as having a clamping assembly108comprising two annular rings208,210each defining a full circumference, it is contemplated that the rings208could be constituted by a plurality of ring sections or segments defining together a complete ring. For instance, a ring could be constituted by three ring segments, each ring segment defining a third of the ring circumference. Further, the clamping assembly108could include two or more complete rings on each side. One will appreciate that many alternate embodiments are possible, where the clamping assembly is operatively connected to two or more knife holders and/or knives so that there is less clamping assemblies than there are knife holders or knives.

FIGS. 22 to 27show another embodiment of a planer head300. In this embodiment, the planer head300includes a cylindrical body302, a plurality of knives304(only one knife being identified with reference numeral304) and a corresponding plurality of knife holders306(only one knife holder being identified with reference numeral306). The knives304and knife holders306have generally the same configuration that the knives104and knife holders106of the planer head100, and therefore, reference will be made to knives104and knife holders106of the planer head100below, where such reference applies. Likewise, the description of the knife pockets118and retaining member138of planer head100apply to the below description.

The body302is similar to body102of the planer head100. As such, elements of the body302will be referred to using the same last two digits of the reference numerals used for the similar elements of the body102but in the300range, while elements that are common to the body102and the body302will not be repeated. The body302differs mainly from the body102in that first inner faces354of the right and left annular recesses350,352are threaded to collaborate with annular threaded fasteners400,402of a clamping assembly404to secure the knives304to the body302, as it will become apparent below.

With reference toFIGS. 23 to 27the clamping assembly404of the planer head300comprises a right clamping sub-assembly406and a left clamping sub-assembly408engageable in the recesses350,352of the body302, respectively. Since the right and left clamping sub-assemblies406,408are mirror images of one another, only the right clamping sub-assembly406will be described. It will be appreciated that a similar description also applies to the left clamping sub-assembly408, with proper adaptation.

The right clamping sub-assembly406comprises a right beveled ring410and the threaded annular fastener400, which is configured to engage the right beveled ring410for securing the same to the body302. The right ring410comprises an outer annular face412having a width W8, an inner annular face414having a narrower width W9and a first curved face416defining an inner diameter D2of the right ring410and extending perpendicular to the inner annular face414(i.e. longitudinally or parallel to a rotation axis R3). The right ring410also comprises a second, beveled face418extending between the outer and inner annular faces412,414. In the illustrated embodiment, the right ring410has a thickness T3, defined between the outer annular face412and the inner annular face414, which is slightly less than a depth d3of the right annular recess350(shown inFIG. 27). It will be understood the thickness T3, defined between the outer annular face412and the inner annular face414of the ring410could be larger than the depth d3of the right annular recess350and yet, allow achieving the purpose of the embodiment. In this case, the ring410would engage the recess350only partially rather than completely, as illustrated inFIG. 27.

Defined on the outer face412of the right ring410, and extending along the inner perimeter thereof, is a recess420sized and shaped to receive a portion of the threaded fastener400. More specifically, the recess420defines an annular flange422onto which abuts the threaded annular fastener400when fasten. As one can appreciate fromFIG. 26, the inner diameter D2of the right ring410is slightly larger than a diameter D3defined by the threaded curved face354of the body302.

As best shown inFIG. 26, as the right ring410moves into the recess350, the beveled face418of the rings410engages the beveled face186of the knife holders306, and force the knife holders306in a radially outward position to secure firmly secure a knife304. To force such movement of the ring410into the recess350, the annular threaded fastener400is screwed onto the inner curved face354of the body302. The annular threaded fastener400has an annular outer face430, an annular inner face432, a curved inner face434defining a diameter D4, and a curved outer face436defining a diameter D5. The curved inner and outer faces434,436extend parallel to one another in a longitudinal direction (i.e. parallel to the rotation axis R3), perpendicular to the outer and inner annular faces430,432. The diameter D4defined by the inner curved face434corresponds to the diameter D3of the inner curved face354of the body302, such that threads440defined on the inner curved face434of the threaded fastener400can engage the threads442defined on the inner curved face354of the body302. The diameter D5defined by the outer curved face436of the annular threaded fastened400is adapted such that the threaded fastener400can be received in the annular recess420of the annular ring410.

To facilitate the screwing of the annular threaded fastener400, a plurality of crenels450is defined along the outer curved face436to receive a fastening tool. It is contemplated that the threaded fastener400could include only one crenel450, or that that the crenels450could be omitted. Instead, the annular threaded fastener400could include protrusions, recesses or other design elements to facilitate screwing of the annular threaded fastener400onto the body202, using tools for instance.

The planer head300further includes a locking bolt460for restricting motion of the annular threaded fastener400relative to the body and prevent unwanted removal of the clamping assembly408due to vibration and centrifugal forces during rotation of the planer head300. In the illustrated embodiment, the bolt460is receivable into a bore462defined in the annular threaded fastener402(although inFIG. 27the bolt is described in connection with threaded fastener402, the description also applies to threaded fastener400) and extending between the outer and inner annular faces430,432thereof. Once the annular threaded fastener400is properly position on the body302of the planer head300, the bore462of the threaded fastener400is in longitudinal alignment with a threaded hole464defined in the recess350of the body302. As it will be appreciated, the presence of the bolt460extending through the bore462of the annular threaded fastener400and engaging the threaded hole464of the body302will prevent any rotational movement of the annular threaded fastener400relative to the body302. In one embodiment, the bolt460is made of heat treated steel. The skilled addressee will appreciate that various alternative embodiments may be provided.

Turning now toFIGS. 25 to 27, the assembly of the planer head302will be described. In a first step, knives304and knife holders306are positioned in the knife pockets318, one knife304and one knife holder306being received in a corresponding knife pocket318. At this stage, the knife holder306are relatively loose in the knife pocket318, therefore allowing alignment of the right and left ends194,196of the knife304and knife holder306with the right and left ends310,312of the planer head body302. Further, the beveled faces386,388of the knife holders306extend in the right and left recesses350,352, as described above in connection with planer head100.

The right and left rings410are pushed towards the body302until they partially engage the right and left recesses350,352, respectively. At this time, the annular threaded fasteners400,402are positioned onto the body302such that the threads440of the threaded fastener400,402engage the threads442of the body302. At this stage, the clamping sub-assemblies406,408are in a distal position relative to one another and the knife304and the knife holder306are still relatively loose in the pocket, therefore being movable therein. As the threaded fasteners400,402are screwed onto the body302, they are received in the annular recess420and abut against the flanges422of the corresponding annular rings410thereby forcing the right and left clamping sub-assemblies406,408to move toward one another, in a proximal position. As the right and left clamping sub-assemblies406,408move towards one another, they gradually engage the corresponding recesses350,352of the body.

As best shown inFIGS. 26 and 27, as the clamping sub-assemblies406,408move into the recesses350,353, toward the proximal position (i.e. a position of the clamping sub-assemblies406,408corresponding to their position during operation of the planer head300), the beveled faces418of the rings410engage the beveled faces386,388of the knife holders306, and force the knife holders306in a radially outward position, thereby firmly securing the knives304to the body302, by frictional engagement. At this time, bolts460are positioned through the bore462of the annular fasteners400and402and screwed into threaded holes464of the body302to prevent unwanted unscrewing to the annular threaded fastener400,402.

Modifications and improvements to the above-described embodiments of the present may become apparent to those skilled in the art. For instance, it should be understood that the planer heads described herein could be positioned in a horizontal position, vertical position, or any angled position between a vertical position and an horizontal position to smoothen a given surface of a lumber. It should also be understood that the planer heads described herein are not limited to be used with wood lumbers, but could be used with any other surface which may require smoothing and for which the rotational cutting of an external layer of that surface would be appropriate. Likewise, the embodiments described herein could find use in cutter head provided with removable knives other than planer heads.