Ring blade knife having wear plate

A hand knife for use in processing meat. The knife has a handle, a circular housing secured to one end of the handle, and a rotatably power driven ring-like blade in part circumferentially contained by the housing. An arcuate wear pad or plate overlies a portion of the inside surface of the blade adjacent the handle limiting movement of the blade away from the blade housing near the handle and against the surrounding housing opposite the handle during use, distributing wear that otherwise occurs between the interior of the surrounding housing and the outside of the blade, and transferring some of the wear to the exterior of the wear plate and the inside of the blade. The ends of the wear plate are tapered outwardly and toward the blade and each has a surface transverse to and overlying the inside surface of the blade. The transverse surfaces form knife edges at the inside surface of the blade and deflects outwardly cut portions of product being processed as they move through the blade and housing and limit their movement circumferentially with the blade.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to hand knives having ring-like rotary cutting 
blades used primarily in the packing house and meat distribution 
industries. 
2. Prior Art 
Hand knives having power-driven, ring-like rotary blades have been used for 
some time in packing houses, meat distribution or wholesale houses and the 
like, for trimming and/or slicing meat and removing meat particles from 
bone. Such knives are commonly referred to as trimming and slicing knives 
and boning knives. Examples of such knives are shown in U.S. Pat. No. 
3,852,882. The ring-like blades are typically supported in the blade 
housing by an external flange on the blade engaging in an interior 
groove-like aperture in the blade housing. The ring-like blades rotate in 
a sliding relationship within a ring-like housing. During use of the knife 
a portion of the blade opposite the handle is pressed against the product 
being processed and normally drawn in the direction of the operator 
causing portions of the blade remote from the handle to be drawn against 
the housing and in some instances the blade is distorted because of its 
relative thinness. The rubbing of the blade against the blade housing 
results in wear of the housing which is typically made of softer material 
than the blade with the result that the blade becomes unduly loose in the 
blade housing reducing the efficiency of the knife and ultimately loss of 
drive. Pressing the blade against the product being processed also tilts 
the blade in the blade housing which results in further wear between the 
blade and housing. 
The concentration of wear between the blade and housing at specific 
locations around the housing as mentioned above results in premature 
weakening of the housing and creates excess clearance between the blade 
and housing, with an accompanying failure of the housing to maintain the 
blade in a position necessary for smooth running of the blade and proper 
engagement of the drive mechanism with the blade. Excess clearance between 
the blade and housing also makes it difficult to effectively hone or 
sharpen the blade without removing it from the housing. Replacement of the 
housing and blades necessitated by such excess wear can result in a 
substantial increase in the cost of using the knives, especially where 
large numbers of knives are used. 
SUMMARY OF THE INVENTION 
This invention provides a novel and improved hand knife having a 
power-driven ring-like rotatable blade in a ring-like housing which knife 
is particularly suitable for use in packing houses and the like and is 
constructed to substantially reduce the wear between the blade and the 
blade housing encountered in similar prior art knives. 
The invention also provides a knife of the character referred to which 
deflects portions of a product cut therefrom by the knife away from the 
product and limits their moving in an arcuate path with the blade. 
The features and objects of this invention are accomplished with a novel 
wear plate or pad of arcuate configuration within the blade and blade 
housing adjacent to the handle which plate during use of the knife engages 
an inside surface of the ring-like blade adjacent the connection of the 
blade housing to the handle. The arcuate wear plate holds the blade 
circular and concentric and firmly in the blade housing and prevents 
tilting of the blade in the housing and transfers much if not all of the 
wear that normally occurs between the outside of the blade and the blade 
surrounding housing to the inside of the blade and wear plate. While the 
hardness of the housing is limited by the fact that it must have 
spring-like qualities, the hardness of the wear plate is not so limited 
and it resists wear to a substantially greater extent. 
An end surface of the wear plate may if so desired be constructed and 
located so as to deflect cut portions of product being processed in an 
outwardly direction and away from the blade as they pass through the 
central opening of the blade and housing and limiting their movement in a 
circular path with the blade. 
The above and other objects, features and advantages of the invention will 
become better understood and more apparent from the following description 
of the preferred embodiment of the invention, when considered with the 
accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
A knife embodying the present invention is shown in the drawings and 
designated generally by the reference character A. The knife comprises a 
relatively thin annular, solid ring-like blade B of relatively short axial 
length having a peripheral cutting edge 10 at one end and supported for 
rotation in a frame assembly C. The knife A is generally similar to that 
shown in FIGS. 1 to 3 of the aforementioned U.S. Pat. No. 3,852,882 and is 
typically referred to as a boning knife. It is to be understood, however, 
that the invention is applicable to the other rotary bladed knives 
including the knife shown in FIGS. 4 and 5 of U.S. Pat. No. 3,852,882, th 
disclosure of which patent is incorporated herein by reference. The frame 
assembly C comprises a tubular handle member 12 having a concave arcuate 
surface 14 at one end, a split ring-shaped blade supporting member or 
housing 16 and an arcuate wear plate or pad 18. The wear plate 18 is 
positioned adjacent the handle members 12 and the split 20 of the housing 
12 is centered on the arcuate surface 14 of the handle member 12. 
The ring-shaped blade B is of short axial length, is rotatably supported in 
the housing 16, with the cutting edge 10 at one end projecting from one 
end of the housing 16. Gear teeth 24 on the other end of the blade B are 
within the blade housing. The blade B is rotated by a gear 26 located at 
the arcuate surface 14 of the handle member 12 and in mesh with the gear 
teeth 24 on the blade B. The gear 26 is rotatably supported in the handle 
member 12 and driven in any suitable manner, such as, in the same manner 
as the corresponding gears of the knives shown in U.S. Pat. No. 3,852,882. 
The blade supporting housing 16 and the plate 18 are detachably connected 
to the handle member 12 by two headed and threaded fasteners 30, 32 at 
opposite sides of the split 20 in the member 16, which fasteners are 
threaded into suitably tapped apertures 34 opening into the arcuate 
surface 14 of the handle member. 
The major part of the housing 16 is of short axial length, being less than 
half that of the blade B, and has portions or parts 40, 42 at opposite 
sides of the split 20 of substantially greater axial length than that of 
the remainder of the member 16. The parts 40, 42 of the blade housing, in 
the depicted embodiment, terminate in surfaces 44, 46 inclined outwardly 
and in the direction of the cutting edge of the blade B. The parts 40, 42 
have axial slots 48, 50 opening into the ends thereof opposite to the end 
of the housing 16 from which the cutting edge 10 of the blade B projects. 
The parts of the shanks of the fasteners 30, 32 adjacent the heads 
thereof, preferably, are reduced in diameter to the root diameter of the 
threads of the fasteners. The portions of the shank of the fasteners of 
reduced diameter adjacent to their heads extend through the slots 48, 50 
in the housing 16 at opposite sides of the split 20. The widths of the 
slots 48, 50 are preferably only slightly larger than shank parts of the 
fasteners that pass therethrough. The exterior of the blade housing 16 at 
the parts 40, 42 abuts the arcuate surfaces 14 of the handle member 12 and 
an axial aperture 52 in each end of the housing 16 at the split 20 
provides clearance for the gear 26. In the knife shown the apertures 52 
open into the upper end of the housing 16 as viewed in the drawings. 
In the knife shown the blade housing 16 is located axially on the concave 
surface 14 of the handle member 12 by two relatively thin flat arcuate 
keys 54, 56 located at opposite sides of the gear 26 and inserted half and 
half in narrow slots 58, 60 in the arcuate surface 14 of the handle member 
and the exterior of the blade housing 16 at the locations of the parts 40, 
42 of the blade housing of increased axial length. 
The construction of the member 16 and the manner of its connection to the 
handle member 12 permits the blade housing 16 and the blade B carried 
thereby to be removed from the handle 12 assembly by merely loosening the 
fasteners 30, 32 sufficient to allow the blade housing 16 to clear the 
keys 54, 56. Thereafter the blade housing 16 and blade B can be readily 
dropped from the handle member 12 as the knife is viewed in the drawings. 
Once the assembled parts 16, B are removed from the other parts of the 
knife the blade B can be easily removed from the member 16 by expanding 
the member. The blade can then be conveniently sharpened and replaced or 
replaced by a different sharp blade. 
The wear plate 18 is arcuate in shape, has, in the embodiment shown, an 
axial length about the same as that of the portions 40, 42 of the housing 
16, a circumferential length about equal to that of the same portions 40, 
42 and is secured against the portions 40, 42 of the housing by the 
fasteners 30, 32. The circumferential length of the member 18 may be 
different than that shown and may, if desired, extend entirely around the 
interior of the member 16. The plate 18 has a cylindrical concave surface 
64 facing toward the center of the ring-like housing 16 and the end 
thereof facing in a direction toward the cutting edge 10 of the blade B 
terminates in a receding frusto-conical arcuate surface 66. The axial 
upper and lower ends of the wear plate 18 have flange portions 70, 72 on 
the convex side of the plate which flanges in the knife shown are of equal 
outside diameter. The flanges 70, 72 are spaced by a cylindrical convex 
surface 74 of smaller outside diameter. The arcuate convex surface 74 on 
the member 18 engages an arcuate concave surface 75 on the member 16. The 
flange portion 70 engages an upper edge of the housing 16. 
The upper end of the flange portion 72 of the plate 18 terminates in a 
beveled or frusto-conical surface 76 which engages a complimentary beveled 
or frusto-conical surface 78 at the lower ends of each of the portions 40, 
42 which portions 40, 42 are thicker than the remainder of the housing 16. 
The added thickness is on the interior or concave side of the housing 
member and provides an arcuate cylindrical surface 80 at the lower ends 
thereof which is abutted by the upper part of a cylindrical arcuate 
surface 82 on the outer or exterior side of the flange 72. The flanges 70, 
72 and the surfaces 76, 82 on the flange 72 of the member 18 and the 
surfaces 78, 80 on the housing member 16 locate the member 18 on the 
housing member in the axial direction. The engagement between the 
cylindrical arcuate surface 82 on the outer or exterior side of the flange 
72 and the complimentary surface 80 on the housing 16 spaces the surface 
82 on the member 18 in the required close proximity to a interior 
cylindrical surface 84 on the upper part of the blade B. The outside 
diameter of the surface 74 of the plate 18 is comparable to the inside 
diameter of the housing portions 40, 42 and fits closely thereagainst, 
while the inside diameter of the surface 80 is just slightly smaller than 
the inside diameter of the blade B by enough to provide a running 
clearance when the blade is concentric with the blade housing and with the 
center of curvature of the wear plate. 
In the drawings the lower surface of the flange 70 on the member 18 and the 
upper end of the member 16; the surfaces 74 on the means 18 and the 
internal surface on the member 16; and the beveled surfaces 76 on the 
member 118 and 78 on the member 16 which engage one another are shown 
spaced for the purpose of facilitating their identification. 
Axially extending slots 90, 92 in the wear plate 18 open through the upper 
or top end thereof to accommodate removal of the plate from the handle 12 
similarly to the removal of the assembled blade B and blade housing 16. 
Opposite ends 94, 96 of the wear plate 18 are inclined, in a manner which 
may be similar to the opposite ends of the parts 40, 42 of the blade 
housing 16. 
A flat portion 100 on the end 96 of the plate 18 and extending the height 
of the beveled portion 66 on the plate, is oriented transversely to the 
inside cylindrical surface 84 of the blade B and faces toward the 
direction from which the blade approaches the surface during rotation in 
the counterclockwise direction as viewed in the drawings. In the preferred 
embodiment the flat portion 100 extends at an angle of about 10.degree. to 
20.degree. from a plane perpendicular to the surface 84 of the blade B, 
forming an acute included angle, preferably of 70.degree. to 80.degree., 
with the surface 82. In the preferred embodiment shown, the plate 18 
extends through about 180.degree. and the flat portion 100 is located near 
the midpoint of the ring-like housing 16, about halfway around the housing 
from the central axis of the handle 12. As a slice is being cut from a 
product being operated upon it tends to travel circumferentially with the 
blade and will be obstructed and deflected upwardly and prevented from 
continued circumferential travel with the blade B by the surface 100 on 
the plate 18, which materially aids the operator in the cutting operation. 
To assure effective deflection of the product, the surface 100 joins the 
surface 82 at a straight knife-like sharp edge 102 that for practical 
purposes rides against and scrapes the inside surface portion 84 of the 
blade B although normally there is a slight clearance between the parts. A 
flat portion 104 at the opposite end 94 of the wear plate 18 is a mirror 
image of the portion 100. Only one surface functions, depending upon the 
direction of rotation of the blade B, which is opposite for right- and 
left-handed use. 
The upper circumferential flange 106 of the blade B extends into the 
interior circular channel 108 of the housing 16 with a small clearance 
between an outer peripheral surface of the flange and the opposed surface 
of the channel. When force is exerted against one portion of the blade, 
such as at the left side of FIG. 3 in a direction away from the handle 12, 
as when the knife is drawn toward the operator, the blade B has a tendency 
to both distort due to its thinness and move toward the left. This 
eliminates any clearance over a limited arc between parts of the opposing 
surfaces of the blade and the surrounding housing, such as the periphery 
of the flange 106 and the bottom surface of the channel 108 causing the 
surfaces to contact along peripherally short portions, resulting in high 
pressure over a limited area with substantial frictional force and 
accompanying wear particularly of the less hard housing. The housing 16 of 
the depicted knife is particularly susceptible to wear because it is 
necessarily made of a metal, such as a steel alloy, soft enough to have 
spring characteristics that accommodate insertion and removal of the 
blade. The blade distortion and movement mentioned above is reduced or 
eliminated by the wear plate 18 which tends to or maintains the blade 
circular and concentric with the housing 16. 
The extensive arcuate length of the plate 18, about 180.degree. in the 
depicted knives, inhibits distortion of the blade, maintains the blade 
concentric with the blade housing and prevents tilting of the blade in the 
housing. With the present knife wear is occasioned primarily between the 
inside surface of the relatively hard blade B and the opposed relatively 
hard metal wear plate 18. Since these surfaces are hard and large, wear on 
the housing 16 is greatly diminished. The effect of the wear plate 18 is 
to transfer the wear from the exterior of the knife B and the interior of 
the blade housing 16 to the interior of the knife B and the exterior of 
the wear plate 18. 
In some operations the knife is moved toward and simultaneously away from 
the operator. In the case of a right-hand operator more or less in the 
direction indicated by the arrow D in FIG. 2, the pressure of the product 
against the blade is in the opposite direction. From the previous 
discussion it will be apparent that the optimum location of an arcuate 
wear plate 18 about the control opening through the blade B and blade 
housing 16 is to have it centered with respect to the pressure on the 
blade. In the depicted knife provision is made for axially adjusting the 
plate 18 relative to the blade holder in the form of circumferential slots 
114, 116 connecting with the bottom ends of the axial slots 90, 92 in the 
plate 18, respectively, and extending therefrom in a clockwise direction 
as the knife is viewed in the drawings. Similar circumferential slots may 
be provided at the opposite sides of the slots 90, 92 either alone or in 
combination with the slots 114, 116. The adjustment of the plate 18 is 
accomplished by loosening the fasteners 30, 32, moving the plates to the 
desired angular position and retightening the fasteners. In place of the 
slot construction described the axial portions 90, 92 of the slots shown 
could be omitted and the circumferential extending slots 114, 116 combined 
into a single circumferential slot opening into one or the other 
circumferential end of the member 18. 
In the depicted knife the flanges 70, 72 of the wear plate 18 and the 
surfaces on the blade housing against which they engage locate the wear 
plate relative to the blade and blade housing to provide the desired 
clearance between the blade and wear plate to produce the optimum 
performance. It will be understood, however, that other constructions may 
be employed to obtain the same results. For example, the adjoining 
surfaces of the blade housing and wear plate may be plain or smooth 
cylindrical surfaces and the wear plate located axially of the knife 
housing by employing countersunk headed fasteners to secure the wear plate 
to the handle assembly or to the blade housing if the blade housing is 
independently connected to the handle member. 
From the foregoing description of the preferred embodiment of the invention 
and suggested alternative constructions it will be apparent that the 
objects heretofore mentioned and others have been accomplished and that 
there has been provided a novel and improved knife especially designed for 
slicing and/or trimming meat and removing meat from bones which has a 
power driven, rotatable blade of short axial length supported in a 
ring-like housing connected to a handle assembly, and which includes a 
wear plate that materially reduces wear of the blade housing and 
incidentally deflects cut portions or a product being processed from the 
blade and prevents them from following the rotation of the blade. 
While a preferred embodiment of the invention has been described in detail, 
it will be apparent that various modifications and alterations other than 
those suggested may be made therein without departing from the spirit and 
scope of the invention set forth in the appended claims.