US3477483A

US3477483A - Knife clamp

Info

Publication number: US3477483A
Application number: US648596A
Authority: US
Inventors: Joseph Andrew Lapointe
Original assignee: Domtar Inc
Current assignee: Domtar Inc
Priority date: 1966-07-14
Filing date: 1967-06-26
Publication date: 1969-11-11
Anticipated expiration: 1986-11-11

Description

Nov. 11, 1969 J. A. LAPOINTE KNIFE CLAMP Filed June 26. 1967 FIG 3 INVENTOR Joseph Andrew LAPOINTE Unit t s Pa se .0

rm. (:1. B27h 13/00 US. Cl. 144-213 '3 Claims ABSTRACT on THE DISCLOSURE The present invention relates to a knife clamp adapted to engage a knife at spaced locations and to also engage one side wall of a knife cavity thereby wedging the knife into engagement with the bottom and other side wall of the knife cavity.

The present invention relates to a knife clamp, more particularly to a mounting for discrete chipper knives to firmly hold and accurately align each knife.

Many different types of knife mounting mechanisms have been proposed for the mounting of discrete knives on chippers or wafering heads. However, each of the prior art devices, unless they were relatively complicated, or machined to very fine tolerances, did not provide means for securely holding the knives in position and for accurately aligning the knives in the chipping or wafering head.

It is therefore the main object of the present invention to provide a new and improved knife clamping system, particularly adapted for holding discrete chipper knives in position.

Broadly, the present invention comprises a knife clamp having a cavity, a pair of opposed side walls and a bottom wall in said cavity, a knife in said cavity and bearing against said bottom wall and one of said side walls, a wedging means overlying and engaging said knife along two spaced lines, said means also contacting the other of said side walls and means forcing said wedging means into engagement with said knife and into contact with said other side wall whereby said knife is forced into intimate contact with said one side wall and with said bottom wall.

Further features, objects and advantages of the present invention will be evident from the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a partial side section view of a simplified chipper or watering head showing a knife clamped in position by the clamping mechanism of the present invention.

FIG. 2 is a view along the line A--A of FIG. 1 showing a wing knife clamped in position.

FIG. 3 is a view similar to FIG. 2 but illustrating means for clamping a flat knife in position.

As seen in FIG. 1 the chipper or wafering head is provided with a cavity 12 into which a knife 14 is clamped. In the illustrated embodiment cavity 12 surrounding the knife has been machined directly through the head. Clearly, the cavity may be formed in a pocket or the like on the head 10 or the machined surfaces of the cavity may be provided by an insert secured onto said head.

The knife 14 is clamped in position by a wedge member 16 which in turn is secured in position by a bolt 18. The head of the bolt 18is received in a cavity 20 provided in the member 16 and the shank of this bolt 18 passes through a bore 22 in the member 16 and a slot 24 in the knife 14 and is screwed into the tapped hole 26 in the head 10. The leading face 28 of the member 16 is bevelled away from the knife 14 and may serve as a chip deflector.

lIn FIG. 2 is the cross-section of the member 16 for use with $3 wing knife is illustrated. The surface 30 of the member 16 engages the knife 14 along spaced lines 32 and 34 (each shown as a point in FIG. 2). The line 32 is the line of contact of the edge of surface 31 of the knife 14 with: surface 30 while the line 34 is the line of contact of one edge of surface, 30. of member 16 with thezwing surface 33 of the knife; The opposite end edge of. the surface30 engages one wall 36 of the cavity 12. Preferably, the angle between the surface 30 and side 38 of the'member 16 is sufliciently less than so that the member16 willjengage the side wall 36 adjacent the surface 30. If this angle is too large the bearing line of the member 16 on the *wall 36 will be moved to the end of the member 16 remote from the knife which may not be stable.

It is evident that a small gap is formed between the knife 14 and the surface 30. However, applicant has found that this gap does not materially affect operation. Another gap is formed between the wall 40 of the cavity and the side 42 of the member 16. Obviously, if desired, the member 16 may be extended to substantially fill this gap.

Tightening of the bolt 18 forces the member 16 into contact with inclined surface 33 which acts as a wedge to move the side 25 of the knife 14 into intimate contact with the wall 40 of the cavity and to move the side 38 of member 16 into intimate contact with side wall 36 of cavity 12. Contact between the side wall of the cavity and the side 25 of the knife accurately aligns the knife and prevents turning of same. The member 16 firmly holds the knife against the bottom of the cavity by pressure applied along the lines of

contact

32 and 34.

The arrangement shown in FIG. 3 is similar to that described above, but illustrates a flat knife 14' held in position using the present invention. In this embodiment the incline plane formed by the surface 33 of the wing knife has been replaced with a surface 52 on a rib 50 forming part of the member 16. The fiat knife 14' is of less width than the cavity 12 so that the rib 50 may extend along one end of the knife. To clamp the knife in position the member 16 engages the knife 14' along two spaced lines 54 and 56 (shown as points in FIG. 3). The line 54 is the line of contact between a corner of the knife 14' and the surface 52 while the line 56 is the line of contact of the corner of the member 16' on surface 30' remote from the rib 50. Preferably the angle between. the side 58 and surface 52 of member 16' is such as to ensure contact between the side 58 and wall 40 as close to the bottom of the cavity as possible.

In the embodiment of FIG. 3, as the member 16' is moved into the cavity the surface 52 contacts the knife and forces the side 60 thereof into contact with the wall 36 of the cavity. The surface 62 of the knife 14 is forced into contact with the bottom 46 of the cavity 12 by pressure of the member 16' exerted along

lines

54 and 56. Thus, the flat knife 14' is firmly held in position and is prevented from rotating by the wedging member 16 and is also accurately aligned by contact with the side of the cavity.

Modifications may be made to the disclosed embodiments without departing from the spirit of the invention asdefined in the appended claims. For example the inclined plane for clamping a flat knife may be a separate element from the remainder of the clamping member.

I claim:

1. A knife clamp comprising: a cavity having a pair of side walls and a bottom wall, a knife in said cavity bearing against said bottom wall and one of said side walls, wedging means overlying said knife and having a planar surface facing a surface of said knife, said planar surface extending in an acute angle to said surface of said knife, said wedging means engaging said knife along a pair of side walls, one of said pair of spaced lines being located at the side edge of said knife remote from said one of said pair of side walls, and the other of said pair of spaced lines being located at the side edge of said planar surface of said wedging means adjacent said one of said pair of side walls, said wedging means engaging said other of said pair of side walls adjacent, but spaced from, said bottom wall and means for forcing said wedging means into engagement with said knife and said other side wall, said knife being forced into intimate face-toface contact with said bottom and said one side wall of said cavity by the wedging action of said wedging means bearing against said knife and said other side wall.

2. A knife clamp as defined in claim 1 wherein said knife has an inclined surface projecting from a side edge of said surface of said knife and wherein said other of said pair of spaced lines is located on said inclined surface of said knife.

3. A knife clamp as defined in claim 1 wherein said clamping means has an inclined surface and wherein said one of said pair of spaced lines is on said inclined surface.

References Cited UNITED STATES' PATENTS 1,493,626 5/1924 Gebhardtetal. 29-105 579,069 6/1933 Germany;

ANDREW R. IUHASZ, Primary Examiner GIL WEIDENFELD, Assistant Examiner US. 'Cl. X.R. 1 29l05; 144162, 172, 175, 241; 241-93, 300