Key deburring and polishing assembly

A key deburring and polishing assembly for keys which have been cut on a key machine or for other metal elements which have uneven or hanging pieces remaining thereon has a frame having a base member and a front end plate and a back end plate connected on opposite ends of the base member and a cover which encloses the frame, driving mechanism mounted in the frame and fixedly connected to a cylindrical drum for rotating the same which drum defines a deburring and polishing chamber open at one end and can be aligned for operative association with the inner face of the front end wall so that abrading material which can be charged into the deburring and polishing chamber of the cylindrical drum by a suitable charging opening will not escape therefrom but with sufficient clearance to permit small particles to escape. The front end plate has an opening to permit a key or other element to be inserted and so positioned that when the cylindrical drum is rotated the inserted end of the key or other device will lie in the path of the rotating abrading material and thus enable the abrading material to deburr and polish the inserted end of the key or other element. Additionally, the combination of a key deburring and polishing assembly as above described with a key making machine for driving the deburring and polishing assembly a jackshaft assembly on the key making machine.

BACKGROUND OF THE INVENTION 
This invention relates generally to key making machines and more 
particularly to an appliance adapted to debur and polish the bow of a 
freshly cut key. 
The cutting of keys on conventional key cutting equipment is an old and 
well established art. However, it has been a continuous problem in the 
cutting of such keys that the bow portion of the key which is cut will be 
unfinished in that it will have burrs or rough edges. If these burrs or 
rough edges are not removed they can cause the key to fail during use or 
alternatively can damage the internal parts of the associated locks 
operated by these keys. 
As a result various devices have been developed to overcome this problem 
such as hand files or for example rotating steel or glass brushes against 
which the keys can be manually pressed to remove the burrs and to polish 
the unfinished surfaces of the cut key as is shown in U.S. Pat. No. 
3,902,382. 
However these prior art devices have problems. Hand filing removes metal 
and must therefore be carefully utilized to avoid changing the profile of 
the cut key. The rotating steel or fiber glass brushes wear rapidly and 
pose a danger to the operator or bystander due to loose bristles or fibers 
which can be thrown randomly in any direction by reason of the centrifugal 
forces during the rotation of such brushes. 
In a busy key cutting shop these brushes can wear out at the rate of at 
least one per week. 
The present invention covers an improved key deburring and polishing 
assembly in which a rotatable container is filled with cutting pellets 
such as Type 100 Nylon Pellets which are rotated in the container at 
relatively high speed so that when the bow of a key is inserted into the 
rotating pellets it will be subjected to sufficient forces and bombardment 
by the pellets to remove burrs and to polish the surface of the key 
without the extensive removal of metal or change in the finish of the key. 
SUMMARY OF THE INVENTION 
Thus, the present invention covers an improved key deburring and polishing 
assembly which includes, a frame, a driving means having a rotatable 
shaft, a cylindrical container defining a deburring and polishing chamber, 
the cylinder has means at one end for connecting the container to the 
rotatable shaft for rotation therewith on operation of the driving means, 
and will be open at the end remote therefrom, abrading material is 
disposed in the deburring and polishing chamber of said cylindrical 
container and an end wall on said frame spaced for operative association 
with the open end of the cylindrical container prevents said abrading 
material from escaping said operatively associated end wall has, a 
predetermined sized and spaced opening extending therethrough to provide 
means for inserting a key into contact with the abrading material in the 
cylindrical container when the container is rotated by the driving means. 
Additionally, the present invention covers the combination of a key making 
machine having a jackshaft extending from one side thereof, and a key 
deburring and polishing assembly connected to and rotatable with said 
jackshaft including, a frame, a cylindrical container defining a deburring 
and polishing chamber connected for rotation at one end with said 
jackshaft and open at the end remote therefrom, abrading material disposed 
in the deburring and polishing chamber of said cylindrical container, an 
end wall on said frame disposed for operative association with the open 
end of the cylindrical container to prevent said abrading material from 
escaping therefrom, and said end wall has a predetermined size and shaped 
opening extending therethrough to permit a key to be inserted for contact 
with the abrading material in the cylindrical container when the container 
is rotated by the key making machine. 
Additionally, key deburring and polishing assemblies and combinations as 
above described including means for charging agrading material into the 
cylindrical container as may be required from time to time. 
OBJECTS AND ADVANTAGES 
Accordingly it is an object of the present invention to provide an improved 
key deburring and polishing assembly as an integral or self-contained 
unit. 
It is another object of the present invention to provide a key deburring 
and polishing assembly which can be disposed for attachment to a jackshaft 
on key making machinery to provide means for deburring and polishing keys 
made on said key making machinery. 
It is another object of the present invention to provide a key deburring 
and polishing assembly which includes, a rotatable container having 
abrading material therein operatively associated with an end wall to 
prevent said abrading material from escaping therefrom during the use of 
said key deburring and polishing assembly. 
It is another object of the present invention to provide a key deburring 
and polishing assembly wherein a rotatable container containing abrading 
material can be operatively associated with the bow of a freshly cut key 
to debur and polish the same. 
With these and other objects the invention will be better understood with 
respect to the illustrated embodiment and the description of the drawings 
as follows.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION 
Referring to the drawings FIGS. 1 to 8 show a self-contained form of the 
key deburring and polishing assembly generally designated 10 in accordance 
with the present invention. 
The key deburring and polishing assembly 10 includes a safety cover 11 
which is removably connected as by threaded members 12a and 12b to the 
inner frame of the key deburring and polishing assembly 10. When the cover 
is removed, the inner frame as shown in FIGS. 3 and 4 has a base plate 13, 
front end plate 14 and back end plate 15 which are connected at their 
lower ends to the respective opposite ends of the base plate 13. Side 
braces as at 16 and 17 act to hold the front end plate 14 and back end 
plate 15 generally normal to the base plate 13. 
FIGS. 1, 2, 3 and 4 further show that the base plate 13 is provided with 
spaced protective buttons on its lower face as at 18 and side flanges as 
at 19 and 20 which permit the key deburring and polishing assembly to be 
placed on a surface or to be affixed as by threaded members, not shown, to 
the top or to the underside of the top of a work bench or other point of 
use for the assembly 10. 
A suitable driving means such as an electric motor 21 is mounted on the 
base plate by means of threaded members 22 adjacent or inwardly of the 
back end plate 15 so that the drive shaft 23 which rotates when the motor 
is in operation is disposed to extend towards the front end plate 14 as is 
clearly shown in FIGS. 3 and 4 of the drawings. 
The electric motor 21 may be any type of conventional motor which operates 
at approximately 7,000 RPM which motors are easily purchaseable on the 
open market. The motor is connected into an electric circuit generally 
designated 40, which includes a suitable line as at 41 and plug 42 for 
connecting the electirc circuit 40 into any suitable source of electric 
current for driving the electric motor. 
As is further shown in FIGS. 3 and 4 the drive shaft 23 is connected by a 
suitable coupling means as at 24 to a key deburring and polishing drum 25 
which defines a key deburring and polishing chamber 26 therein. 
The key deburring and polishing drum 25 is a generally cylindrical 
cup-shaped hollow container which is closed at the end having the 
connecting coupling 24 thereon and which forms an open or mouth end 27 for 
the key deburring and polishing chamber remote from the connecting 
coupling 24. 
The connecting coupling 24 is shown as having at least two spaced threaded 
members 28a and 28b to fixedly connect the key deburring and polishing 
drum 25 to the rotatable drive shaft 23. These threaded members 28a and 
28b are adjustable and also serves to align the transverse and 
longitudinal axis of the key deburring and polishing drum 25 and to hold 
the drum 25 in assembled position so as to reduce excessive eccentricity 
during rotation of the key deburring and polishing drum 25 during 
operation of the electric motor 21 at speeds of 7000 RPM and to maintain 
the end 29 of the key deburring and polishing drum 25 from frictional 
engagement with the inner face of the front end plate. 
It is imperative as shown in FIGS. 4, 6 and 7 that the annular end 29 of 
the key deburring and polishing drum 25 disposed about the mouth 27 of the 
key deburring and polishing chamber operate with as little eccentricity as 
possible because the end 29 and mouth 27 of the key deburring and 
polishing drum 25 must be positioned for operative association with the 
inner face of the front end plate 14 for reasons that will appear clear 
from the further description below. 
In order to provide effective operation of the key deburring and polishing 
assembly in accordance with the present invention, a mechanism is provided 
for both removing the burrs and for polishing the bow of a newly cut key 
without removing an excessive amount of material from the bow of the key. 
Additionally, means must also be provided for bringing the bow of the key 
into operative engagement with the mechanism for deburring and polishing. 
Thus, referring to FIGS. 4 to 8 of the drawings the key deburring and 
polishing drum 24 is shown with the key deburring and polishing chamber or 
space 26 filled with a plurality of sized abrasive pellets generally 
designated 30 which are filled through the filling opening 31 in front 
plate 14 to within approximately 1/2" of the open or mouth end 27 of the 
key deburring and polishing chamber 26. 
Various types of abrasive pellets or sized and shaped materials may be used 
to accomplish the desired result of deburring and polishing in accordance 
with the present invention. For example, aluminum oxide pellets, silicone 
carbine pellets, carborundom pellets, and nylon pellets may be utilized 
for this purpose. 
However, the preferred abrasive material is nylon pellets idnetified 
as--Type 100 Nylon Pellets--which are sold in fifty pound bags on the open 
market by the Ashland Oil Corp. of Ashland, Ky. These nylon pellets are 
well known for use in injection molding processes in the plastic field. 
Such pellets will have an uneven shape and are generally non-uniform. 
Thus, when the key deburring and polishing drum 25 is rotated by the drive 
shaft 23 the nylon pellets will abrade the bow of a key which is inserted 
into the path of these rotating pellets thus removing the burrs and 
polishing the keys. These pellets become more effective with use, this may 
be due to the rouding of the corners on the non-uniform sized and shaped 
pellets. 
Additionally, in order to prevent the abrasive material from escaping 
through the mouth 27 of the key deburring and polishing chamber, the key 
deburring and polishing drum is so disposed relative the inner face of the 
front end plate that there will be a limited clearance between the annular 
end 29 of the key deburring and polishing drum and the inner face of the 
front end plate 14 as is clearly shown in FIGS. 4, 6 and 7 of the 
drawings. 
Further, the front end plate 14 is provided with a slot or orifice 32 
therethrough which is sufficiently large to permit the bow end B of a key 
to be inserted through the front end plate into predetermined operative 
position in the key deburring an polishing chamber. Therefor, when the key 
deburring and polishing drum is rotated the key will lie in the path of 
the abrasive material rotating with the key deburring and polishing drum 
in an approximate position nearer to the inner wall of the key deburring 
and polishing chamber then to the longitudinal centerline about which the 
key deburring and polishing assembly will rotate, as is clearly shown in 
FIG. 7 of the drawings. 
FIGS. 4, 5, 6 and 7 further show that the slot 32 is generally disposed 
parallel to the axis of rotation so that the bow end of the key when 
inserted into the key deburring and polishing chamber 26 will be 
approximately within 3/8" to 1/2" inwardly of the inner wall of the key 
deburring and polishing drum 25 and will so lie in the path of the 
abrasive material in the key deburring and polishing chamber that the 
abrasive material will flow against and about the newly cut portion of the 
bow thereby permitting the abrasive material to remove the burrs and 
polish the bow portion of the key without removing excessive amounts of 
metal during the deburring and polishing process, as is clearly shown by 
FIGS. 7 and 8 of the drawings. 
In order to protect the operator of the self-contained key deburring and 
polishing assembly 10, a safety cover 33 is affixed by threaded members 34 
and has an enlarged mating slot 35 which is in alignment with the slot or 
opening 32 in the front plate. Between the safety cover 33 and the 
exterior surface of the front end plate 14 an elastomeric shield 36 with a 
matching opening as at 37 is provided so that when a key is inserted 
through the aligned slot 35, 37 and 32 to deburr and polish the bow end of 
the key the operator will be protected and the key will simultaneously be 
set in the optimum position for the deburring and polishing operation of 
the key deburring and polishing assembly 10. 
The front end plate will be sized larger than the diameter of the key 
deburring an polishing drum 25 and the safety cover 33 and elastomeric 
shield 36 will also be sized not only to permit alignment of the enlarged 
mating slot 35 with the slots 37 and 32 but will also cover the filling 
opening 31 all of which is clearly shown in FIGS. 1, 2, 4, 5, 6 and 7 of 
the drawings. 
The clearance between the annular end 29 of the key deburring and polishing 
drum 25 and the inner face of the front end plate 14 will be such that it 
will prevent the escape of the abrasive material but will permit the waste 
dirt particles DP such as the materials removed during the deburring and 
polishing operation to escape through this clearance. The outer cover 11 
will be provided with louvers as at 38 on opposite sides of the key 
deburring and polishing assembly 10 so that during the rotation of the key 
deburring and polishing drum 25 the air pressures which inherently develop 
will automatically drive the waste dust particles from the inside of the 
cover element 11 to the exterior of the key deburring and polishing 
assembly 10. 
In order to place the key deburring and polishing assembly into operation a 
switch 39 is mounted on the front end plate 14 adjacent to the point where 
the bow of the key will be inserted through the enlarged slot 35 so that 
it will be relatively easy for the user of the key deburring and polishing 
assembly to turn on the motor. Switch 39 controls the flow of electrical 
current through the electrical circuit which includes, the switch 39, the 
motor 21, the lines 41 and 42 which connect the electrical circuit to a 
suitable source of power or current for operating the motor. 
The switch 39 will be of the push button or intermittent type which can be 
operated by manual pressure to actuate the motor 21 and which will 
terminate flow of current to the motor, when released. 
OPERATION 
The user will first press the switch 39 to actuate the motor 21 to rotate 
the drive shaft 23. Drive shaft 23 will in turn through the coupling 24 
cause the key deburring and polishing drum 25 and the abrasing material 30 
thereon to rotate with the drive shaft 23 at the operating speed of the 
motor 21. 
The newly cut key will be grasped manually and the bow end B thereof 
inserted through the slot 35 and the aligned slots 37 and 32 into the 
abrasive material 30 in the key deburring and polishing chamber 26. 
As the key deburring and polishing drum 25 operates it will cause the 
abrasive material in the key deburring and polishing chamber to move under 
centrifugal force into engagement with the inner wall of the key deburring 
and polishing chamber where under the rotary forces acting the abrasive 
material will pass over, around and against the bow end 13 of the key in a 
lamine flow to thereby deburr and polish the said bow end B of the key as 
is clearly shown in FIGS. 7 and 8 of the drawings. 
The rotation of the key deburring and polishing drum will be maintained for 
approximately two to six seconds. Thereafter the switch 39 will be 
released and the rotation of the key deburring and polishing drum will 
terminate. The key is then withdrawn from the aligned slots 35, 37 and 32 
an examined to be certain that all of the burrs have been removed and the 
bow end of the key properly polished so as to avoid the problems of 
malfunction with the mating lock which occurs if the key is not properly 
deburred and polished, as will be understood by those skilled in the art. 
MODIFIED FRONT END PLATE 
While the self-contained key deburring and polishing assembly 10 above 
described has suggested the use of Type 100 Nylon Pellets those skilled in 
the art will readily recognize that more abrasive materials can be used 
for not only deburring and polishing keys but also other elements of 
freshly cut metals. Therefore where such stronger abrasive materials such 
as aluminum oxide pellets, silicone carbine pellets or carborundum pellets 
are utilized as a further protection to avoid frictional engagement and/or 
wear on the front end plate, the front end plate can be modified to 
provide a suitable coating thereon of aluminum oxide 50 as is shown in 
FIG. 10 of the drawing. 
The structure and operation with this modified front end plate will be 
otherwise identical with that as above described for the self-contained 
form of the invention shown in FIGS. 1 to 8 of the drawings. 
ATTACHMENT TO A KEY MAKING MACHINE 
FIGS. 11 to 15 show an alternate embodiment of the invention in the form of 
an attachment to the jackshaft end of a key making machine for small key 
making shops. As was indicated above, the prior art shows that the 
jackshaft end of the key making machine can have a steel or a fiberglass 
brush connected thereon which can be utilized to deburr and polish the bow 
end of a newly cut key. This conventional and well known practice is for 
example shown in U.S. Pat. No. 3,902,382. The present invention also can 
be modified for attachment to the jackshaft end of a key making machine. 
Thus, by reference to FIGS. 11 to 15 a generally U-shaped frame 111 is 
shown having spaced end plates as at 112 and 113. End plate 113 is 
provided with a suitable opening as at 114 to permit the U-shaped frame 
111 to be mounted about the jackshaft 115 and connected to the adjacent 
end of the key mounted casing 116 as by threaded members 117. 
A suitable sized key deburring and polishing drum 120 will have a 
connecting coupling 121 for connecting the key deburring and polishing 
drum 120 to the end of the jackshaft 115 which extends into the U-shaped 
frame 111 in assembled position as is shown in FIGS. 11 and 13 of the 
drawings. 
The key deburring and polishing drum 120 is identical with that above 
described for the self-contained form of the invention except that it will 
be sized to fit in assembled position on the jackshaft within the U-shaped 
frame so as to coact with the lower face of end plate 112. Key deburring 
and polishing drum 120 defines the key deburring and polishing chamber 121 
therein which receives the abrasive material 122 in the same manner above 
described for the self-contained form of the invention except that the 
filling of the deburring and polishing chamber 21 will be done through a 
side filling opening 124 in the wall of the key deburring and polishing 
drum 120, which is normally maintained closed by a removable filling cap 
123. 
The end plate will have a slot 125 over which will be provided a suitable 
safety cover 126 having an enlarged aligned mating slot 127 and an 
elastomeric shield 128 with an aligned opening 129 therethrough so that a 
key can be extended through the front plate into the key deburring and 
polishing chamber 121 in the key deburring and polishing drum 120. 
A pivotally mounted safety cover 131 will be provided on the frame 111 with 
a suitable latch means, not shown, and louvers 137 so that the cover can 
be pivoted to expose the key deburring and polishing drum 120 to permit 
the key deburring and polishing chamber to be filled through the filling 
opening 124 by removing and replacing the normally closed filling cap or 
cover 123 therein. 
OPERATION 
When the jackshaft 115 of the key making machine is placed in operation it 
will rotate the key deburring and polishing drum 120 causing the abrasive 
material therein to rotate. The bow of the key to be deformed and polished 
is inserted through the aligned slots 127, 129 and 125 into engagement 
with the abrasive material and removed after five to ten seconds in the 
same manner as was described for the self-contained form of this 
invention. 
Tests of the present invention as above described show that the 
self-contained unit is ideal for a work bench because it can be mounted on 
the underside of the top of the work bench. Additionally, it does not 
vibrate and has a built in safety factor because the moving parts are 
isolated from the user. 
Key deburring and polishing assemblies and/or adaptors for key making 
machines as herein described are ideal because they require minimum 
hand/eye coordination and because of the built in safety factor will not 
injure an inexperienced operator of the machine. 
Further, tests show that key deburring and polishing done on machines as 
herein described require but little skill and produce a smoother and more 
effective finish to the bow end of a freshly cut key then the known prior 
art devices. 
While the foregoing description illustrates various preferred embodiments 
of apparatus and systems in accordance with the present invention, it will 
be appreciated that certain changes and modifications may be made in the 
structure of these disclosed arrangements without departing from the 
spirit and scope of the invention and that the same is defined by the 
claims as hereinafter set forth.