US3828486A

US3828486A - Sharpening device

Info

Publication number: US3828486A
Application number: US00307578A
Authority: US
Inventors: H Bonke
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-11-17
Filing date: 1972-11-17
Publication date: 1974-08-13
Anticipated expiration: 1991-08-13

Abstract

Apparatus for sharpening the shaft mounted blades of a planarjointer including a base member for mounting onto the planarjointer table over the blades thereof and positioning means mounted onto the base member for positioning the base member and a blade of the planar-jointer for sharpening.

Description

limited States Patent 1191 lBonke Aug. 13, 1974 [54] SHARPENING DEVICE 2,729,923 l/l956 Durst .Q 51/249 Y 2,792,036 5/1957 B ttk 51/249 [76] inventor: Henry F" 2605 3,354,589 11/1967 Pt i stufa et al.. 51/249 Colorado Springs, Colo- 80904 3,691,702 9/1972 Smith 51/249 [22] Filed: Nov. 17, 1972 Przmary ExammerOthell M. Simpson PP 307,578 Attorney, Agent, or Firm-Pravel, Wilson & Matthews 52 us. 01. 51/249 [57] ABSTRACT [5 l Int. Cl B24b 19/00 Apparatus for Sharpening the shaft mounted blades of [58] Field of Search 51/246, 247, 249 a planar-jointer including a base member for mounting onto the planar-jointer table over the blades thereof [56] References Cited and positioning means mounted onto the base member UNITED STATES PATENTS for positioning the base member and a blade of the 900,284 10/1908 Kahle 51 /249 planar'lomer for Sharpening 2,664,641 l/1954 Parnet 51/216 H 8 Claims, 5 Drawing Figures 5 2 20 Z0 23 /Z& i 1 S 246 t l l 3 //Q /0 "a P A; 7 3 /4a /5 m, 0

SHARPENING DEVICE BACKGROUND OF THE INVENTION The field of this invention is sharpening devices.

A planer-jointer is well-known in the field of woodworking for cutting or planing wood surfaces. A typical planer-jointer has a shaft-mounted rotating cutting head having blades extending outwardly therefrom. Generally, the blades of a planer-jointer are removed from the cutting head for sharpening and thereafter replaced. The replacing of the blades in the cutting head is very tedious since the cutting height of such blades is critical.

Various attempts have been made to devise an apparatus for sharpening planer-jointer blades without removing them from the cutting head. For example, US. Pat. No. 2,729,923, issued to Durst, disclosed a sharpening device which included a base plate and a carrier plate for mounting over the planer-jointer table. In Durst, the carrier plate is pivoted to a position over the open area of the planer-jointer table and' rails are provided for guiding a grinder in a transverse movement along a blade, which is held in position by an arm attached to a shaft pulley and by a blade indexing block.

SUMMARY OF THE INVENTION It is an object of this invention to provide a new and improved apparatus for sharpening in place the blades of a planer-jointer. The sharpening apparatus of this invention includes a base member having an opening therein such that the base member may be placed on a planer-jointer table with the base member opening aligned with the open space between the-sections of the planer-jointer table. Base member positioning means is mounted on the base member for engaging a section of the planer-jointer table in order to position the base member thereon. The blade of the p'laner-jointer to be sharpened is positioned by a stud extending outwardly from the base member into engagement with the underside of the blade and, guide members are mounted onto the base member on opposite sides of the base member opening in order to, guide a grinder along the planerjointer blade.

As an additional feature, a locking arm is clamped onto the planer-jointer shaft and rests against the table in order to secure the shaft against movement.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a sectional view in elevation illustrating the sharpening device of the preferred embodiment of this invention in position on the table of the planer-jointer;

FIG. 2 is a top view taken along line 2 2 of FIG. 1 of the sharpening device;

FIG. 3 is a bottom view taken along line 3 3 of FIG. 1 of the sharpening device with the position of the planer-jointer table being illustrated schematically;

FIG. 4 is a sectional view taken along line 4 4 of FIG. 2 illustrating various positioning elements for the sharpening apparatus; and

FIG. 5 is a side view of the shaft locking arm of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, the letter S generallydesignates a sharpening device for sharpening a planer jointer (or jointer) P without having to remove the 0 nated as T. The table T includes a front section 12 and l a rear section 14 separated by open area 0. The open area or space between the front table section 12 and the rear table section 14 is defined by front'table section inside wall 12a and rear table section inside wall The cutting head 11 is mounted onto shaft 15 for rotation therewith by any suitable means such as keys (not shown). The cutting blades 10 are mounted in substantially radially directed slots 1 la in the cutting head 11 such that the blades 10 extend radially outwardly from the periphery 11b of the cutting head. The cutting blades are held in place by set screws (not shown) or other suitable means. If the blades 10 must be removed in order to be sharpened, the blades must be replaced in the cutting head 11' such that each blade cuts at exactly the same level and angle, which requires a great deal of tedious effort. The shaft 15 is mounted for rotation onto some type of frame (not shown) by any suitable means such asbearings 16a and 16b. A pulley 17 is mounted for rotation with the shaft 15 and is driven by a motor and belt combination (not shown). The height of the front table section 12 of the planer-jointer P is adjustable "such that the thickness of the wood to be removed by planing is adjustable. Generally, the cutting point 10a of the cutting blade is adjusted or set to an elevation (at the highest point) substantially equal tothe elevation of the top 14b of the rear table section 14 such that the thickness of material being planed by the planer-jointer P is measured by the difference in height between the top 1412 of the rear table section and top '12b of the front table section.

The sharpening device S of the preferred embodiment of this invention includes a flat, base member or plate 20 having an oblong opening 21 extending transversely thereof. The base member 20 may be a plastic or other suitable material, preferably light weight and translucent. Side blocks 23 are mounted onto each of the four 'corners 20a'of the base member 20. Each side block 23 has a slot 23a therein extending transversely 26 to the longitudinal axis 24 of the planer-jointer table T. Screws 25 extend through the slot 23a and into threaded engagement with underside 20b of the slot 23a and into threaded engagement with underside 20b of the base member 20. Each of the side blocks 23 are sufficiently thick to extend down over the sides of the front and

rear table sections

12 and 14, respectively. For example, side blocks 23 extend downwardly over the top 12b of the front table section 12 and are positioned for engagement against side walls and 12d of the front table section 12. By adjusting the side blocks until such blocks abut against the sides such as 120 and 12d of the

table sections

12 and 14, the base member 20 can be secured against transverse movement 26.

As previously mentioned, the front table section 12 is adjustable in height with respect to the height of the rear table section 14; and, in utilizing the sharpening apparatus S of this invention, it is desirable that the front table section 12 be slightly lower in elevation or height than the rear table section 14. In order to compensate for such difference in height, stabilizing

plates

27 and 28 are mounted onto underside 20b of the base member 20 by any suitable means such as gluing. The thickness of the stabilizing members or

plates

27 and 28 is sufficient to compensate for the desired height difference between front table section 12 and rear table section 14 of the planer-jointer P. Thus, when the base member 20 is mounted over the front and rear table sections 12 and.14, the stabilizing

plates

27 and 28 rest upon front table section top 12b such that top surface 20c of the base member 20 is substantially level.

Stabilizer plate 27 includes a recessed area 27a. A metal stud or plate 30 is mounted in recess 27a and includes a portion 30a which extends outwardly into the area of base member opening 21 in order to engage underside b of a cutting blade 10 to thereby position a cutting blade 10 at the desired angle or bevel for sharpening. The edge 30b of the plate 30. is beveled such that the underside 10b of the blade 10 being sharpened can rest thereagainst at an angle. In this manner, the cutting surface 10c of the blade 10 is held at substantially a level or horizontal position for sharpening. The blade positioning plate 30 is adjustably mounted within the recess 27a in the stabilizer plate 27. Oblong slots 31 and 32 are machined into the base member and into stabilizer plate 27 and adjusting

screws

33 and 34 extend through the oblong slots 31 and 32 into threaded engagement with the plate 30. Thus, by loosening the

screws

33 and 34, the position of the base plate with respect to the blade 10 can be adjusted as desired.

Base

member positioning elements

35 and 36 are also mounted in recess 27a in the stabilizer plate 27. The L-

shaped elements

35 and 36 include vertical portions 35a and 36a, respectively, which extend downwardly in order to be placed against front table section inside wall 12a. The

positioner elements

35 and 36 are adjustably mounted within the recess 27a. Oblong slots 37 and 38 are machined into the base member 20 and into the stabilizer plate 27 such that

adjustment screws

39 and 40 can be mounted in slots 37 and 38, respectively, and extend into threaded engagement with the

elements

35 and 36. The function of the L-

shaped elements

35 and 36 is to position the base member 20 such that the blade positioning plate 30 and base member opening 21 are aligned properly with respect to the cutting head 11 and the blade 10 to be sharpened.

A locking arm 42 is attached to end 15a of the shaft 15 and extends onto rear table section top 14b in order to secure the shaft 15 against counter-clockwise rotation (HO; 1) while the blade 10 is being sharpened. The locking arm 42 includes an end portion forming a collar 42a which extends about the shaft 15a with a bushing or sleeve 43 positioned therebetween. The

bushing or sleeve can be polytetrafluoroethylene orother suitable material which will protect the shaft 15a. The collar end portion 42a extends about the bushing 43 and includes a clamping portion 42b having a clamping nut 42c extending therethrough into threaded engagement with the main portion 42d of the locking arm 42. Thus, the collar end portion 42a and bushing 43 are mounted over the shaft end 15a and the clampin'g nut 42c is screwed tightly to draw the clamping end shaft end 15a. The main body portion 42d of the arm is L-shaped such that a portion 42e extends inwardly into a position of engagement with rear section table top 14b. Actually, the portion 42e of the locking arm includes a vertical connecting portion 42f and a horizontal tip 42g which actually is positioned to engage the rear section table top 14b.

A grinder G is used to actually grind the blade 10 being held in place by the blade positioning plate 30 and shaft locking arm 42, which cooperate to prevent rotation of shaft 15 (and thus blade 10) in either clockwise or counter-clockwise direction (see FIG. 1). The grinder G is of typical grinder construction and includes a motor 45 having a circular housing 45a mounted therewith, the circular housing including a bottom rim 45b. The motor shaft 45c extends downwardly from the motor 45 and a grinding head 45d is mounted thereon. The housing 45a serves to protect the user from flying particles from the grinding operation. Guide bars 46 and 47 are provided on opposite sides of the opening 21 in the base member 20 in order to provide a guide path for the grinder G. The guide bar 46 has oblong slots 46a and 46b and, a plurality of screw holes such as 480 and 48b are machined in the base member 20. A screw 49 extends through each of the oblong slots 46a in the guide bar 46 and into one of the plurality of holes 4811 and 48b. In this manner, the relative position of the guide bar 46 can be adjusted when the screws 49 are in one of the holes 4811 and 48b and, the position of the guide bar 46 can be even further varied by threadedly mounting the screws 49 in any of the other holes 480 and 48b.

Similarly, the guide bar 47 has oblong slots 47a and 47b therein and sets of aligned holes 500 and 50b are located in the base member 20. Screws 51 extend through the slots 47a and 47b and into the holes 50a and 50b. Thus the relative position of the guide bar 47 with respect to oblong base member opening 21 can be adjusted by using the screws 51 and/or any of the holes 50a and 50b. Guide bars 46 and 47 provide inside rails or

edges

46c and 47c for receiving and guiding grinder housing rim 45b. in this manner, various sizes of grinders G may be utilized to sharpen the planer-jointer blades 10. No matter what the size of the grinder G is, the guide bars 46 and 47 are adjusted on the base member 20 such that grinder head 45d is positioned therebetween to engage and move along the blade 10 being sharpened.

In operation and use of the sharpening apparatus S to sharpen the blades 10 of a planer-jointer P, the blades 10 are first cleaned in order to remove any dirt, oil or grime thereon. The sharpening apparatus S is then placed onto the front and

rear table sections

12 and 14. The front table section 12 is lowered until the top surface l2b thereof is approximately one-quarter of an inch lower in elevation than the top surface 14b of the rear table section 14. The base member 20 with the stabilizing

plates

27 and 28 engaging top front table section surface 12b is then tapped or otherwise maneuvered until the top surface 200 is substantially horizontal or level. The side blocks 23 are then adjusted to engage the sides such as 12c and 12d of the front table section 12.This is accomplished by loosening screws 25 and moving the blocks 23 into engagement with the sides of the table section and thereafter screwing tight the screws 25 again. The base member 20 is then pulled or pushed away from rear table section 14 until the ver- The blade positioning plate 30 is then positioned to engage underside b of one of the bladeslO in order to properly position cutting surface or edge We of the blade and prevent rotation of the blade 10 in a clockwise direction under the force of the grinder G (FIG. 1). The objective is to position the blade 10 to be sharpened such that the cutting surface 10c is substantially horizontal in order to prevent unnecessary cutting or ruin the bevel of the cutting blade 10. The blade positioning plate 30 is adjusted in position by loosening

screws

33 and 34 such that the screws are free to move within oblong slots 32 and 31, respectively. Thereafter, the

screws

33 and 34 are tightened to secure the plate 30 and thus the balde 10 being sharpened, as illustrated in FIG. 1, in the desired position. The locking arm 42 is then mounted over shaft end portion a by mounting the bushing 43 and collar end portion 42a over the shaft end 15a. Clamping screw 42c is then tightened to tighten the collar end portion 42a about the shaft end portion 15a. The locking arm 42 is positioned such that horizontal tip 42g is resting onto rear section top table surface 14b prior to the collar end portion 42a being locked or clamped about the shaft end'portion 15a. In this manner, the shaft 15 islocked against rotational movement in any direction under the force of the grinder G. The guide bars 46 and 47 are positioned such that the distance therebetween is substantially equal to the diameter or width of the grinder housing edge 45b so that the grinder G can be moved across the blade 10 to be sharpened smoothly. The actual height of the blade 10 being sharpened is determined by the position of the grinder head 45d. Of course, it is desirable to sharpen all three of these blades 10 without changing any of the adjustments on either the sharpening apparatus or the grinder G such that the cutting heights of the blades 10 are identical.

The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape, and materials as well as in the details of the illustrated construction may be made without departing from the spirit of the invention.

For example, it should be understood that the various elements such as base member 20, which has been disclosed as being plastic, or the metal plate 30 can be made of other suitable materials than those discussed. Further, it should be understood that the sharpening apparatus S may be used'with various types of grinders other than the grinder G disclosed and that the sharpening apparatus S may be adapted for use on various sizes of planer-jointers P.

I claim:

1. Apparatus for sharpening a planer-jointer having a shaft with blades mounted thereon positioned inan open area in a planer-jointer table, said apparatus being adapted for use with planer-jointers of different sizes and comprising:

a base member having an opening therein, said base member adapted for mounting on said table such that said base member opening substantially aligns with said open area of said planer-jointer table; base member positioner means for engaging said table at said open area for positioning said base member on said table; said base member positioner means including:

horizontal members extending from said base member parallel to the top of the planer-jointer 'table; and

vertical portions mounted with said horizontal members for engaging the table at its open area;

blade positioner means mounted on said base member for adjustable extension parallel to the top of the table to engage a blade and position the blade;

guide members mounted on said base member about said base member opening for guiding a grinder along a blade;

base member positioner adjusting means for adjusting the extension of said base member positioning means from said base member to control the position of said base member on the table; and

blade positioner adjusting means for extending and retracting said blade positioner means from said base member, whereby said base member and the blade are positioned independently to permit positioning of said apparatus on planer-jointers of different sizes and the blades of the planer-jointer are sharpened without removal. 2. The structure set forth in claim 1 including: shaft lock means attached to said shaft and extending to said table for locking said shaft against rotation.

3. The structure set forth in claim 1, including:

side blocks adjustably mounted on each corner of said base member; and

adjusting means for adjusting the position of each of said blocks with respect to said base member and said table to position said base member on said table and secure said base member.

4. The structure set forth in claim 1, wherein:

said base member is of unitary construction.

5. The structure set forth in claim 2, wherein said shaft lock means includes:

a collar portion for mounting about said shaft; and

clamping means for clamping said collar portion onto said shaft.

6. The structure set forth in claim 5, including:

a bushing mounted within said collar portion for preventing damage to said shaft.

7. The structure set forth in claim 2, wherein:

said blade positioner and said shaft lock means cooperate to prevent movement of said blade being sharpened in any direction.

8. The structure set forth in claim 1, including:

means mounted on said base member for adjusting the position of said guide members on said base member.

Claims

1. Apparatus for sharpening a planer-jointer having a shaft with blades mounted thereon positioned in an open area in a planerjointer table, said apparatus being adapted for use with planerjointers of different sizes and comprising: a base member having an opening therein, said base member adapted for mounting on said table such that said base member opening substantially aligns with said open area of said planer-jointer table; base member positioner means for engaging said table at said open area for positioning said base member on said table; said base member positioner means including: horizontal members extending from said base member parallel to the top of the planer-jointer table; and vertical portions mounted with said horizontal members for engaging the table at its open area; blade positioner means mounted on said base member for adjustable extension parallel to the top of the table to engage a blade and position the blade; guide members mounted on said base member about said base member opening for guiding a grinder along a blade; base member positioner adjusting means for adjusting the extension of said base member positioning means from said base member to control the position of said base member on the table; and blade positioner adjusting means for extending and retracting said blade positioner means from said base member, whereby said base member and the blade are positioned independently to permit positioning of said apparatus on planer-jointers of different sizes and the blades of the planer-jointer are sharpened without removal.

2. The structure set forth in claim 1 including: shaft lock means attached to said shaft and extending to said table for locking said shaft against rotation.

3. The structure set forth in claim 1, including: side blocks adjustably mounted on each corner of said base member; and adjusting means for adjusting the position of each of said blocks with respect to said base member and said table to position said base member on said table and secure said base member.

4. The structure set forth in claim 1, wherein: said base member is of unitary construction.

5. The structure set forth in claim 2, wherein said shaft lock means includes: a collar portion for mounting about said shaft; and clamping means for clamping said collar portion onto said shaft.

6. The structure set forth in claim 5, including: a bushing mounted within said collar portion for preventing damage to said shaft.

7. The structure set forth in claim 2, wherein: said blade positioner and said shaft lock means cooperate to prevent movement of said blade being sharpened in any direction.

8. The structure set forth in claim 1, including: means mounted on said base member for adjusting the position of said guide members on said base member.