Computer controlled apparatus for imparting a design onto the surface of a candle

A system and method are disclosed for automatically stamping designs onto candles under computer control. For a given stamped mark, a turret selects the tool with a specific die is to be stamped. The turret orients the tool angle about the axis defined by the tool's travel line during stamping by use of a planetary gear system. A rotatable chuck mounted on a movable bed selects the location on the candle surface to receive the die. A linear solenoid plunges the selected and oriented tool onto the candle. This process is repeated until all marks in a desired design are completed. The planetary gear system is designed so that all tool orientations are controlled by one motor, and tool anti-rotation during travel is controlled by the face length of a sun gear.

BACKGROUND OF THE INVENTION 
(1) Field of the Invention 
This invention relates to candle decorating, and more particularly to an 
automated mechanized, apparatus and process for the reproduction of hand 
decorated designs on candles. 
(2) Description of the Prior Art 
The art of hand stamping decorations on large candles is known. To manually 
decorate a candle, the craftsperson must hold the candle in his lap and 
strike its surface with the tool that imparts a desired mark. The mark 
consists of an indentation in the candle and depending upon the wax 
composition, a milky white region of tiny cracks localized around the edge 
of the indentation. Craftspersons in this art generally combine up to 
eight different tool shapes to create intricate decorations such as 
flowers and plants on the surface of a candle. 
Most decorated candles require on the order of a thousand marks. Many of 
the marks are applied at various angles. A flower, for example, requires a 
center hub mark and petal marks angled radially about the hub. Each change 
of angle requires the craftsperson to rotate the candle in his lap before 
striking the mark. The manual method is therefore not satisfactory for the 
repeated reproduction of stamped candle decorations. 
The prior art method of decorating candles is laborious, requires skilled 
labor, and does not lend itself well to large scale production and is 
generally exceedingly time consuming. 
I have invented an automated-mechanized apparatus and method for the 
reproduction and production of decorated candles previously capable of 
being only made by hand. 
SUMMARY OF THE INVENTION p This invention is directed to an apparatus: 
For imparting a predetermined ornamental design into the surface of a 
candle or leather good comprising: 
A computer controlled apparatus for impressing a design onto the surface of 
a work piece comprising: means for selecting a working tool having a die 
from a plurality of tools said working tool having placed in a fixed 
position and having a linear line of travel; movable support means for 
holding the work piece and which is capable of positioning the work piece 
in relation to the fixed position of the working tool; so that a selected 
position on the surface of the work piece is positioned along the line of 
travel of the working tool; means for orienting the working tool die about 
an axis normal to the surface of the work piece; plunger means for 
striking said working tool onto the work piece thereby impressing the die 
of the working tool onto the work piece; computer means comprising a 
computer and computer software programmed to produce the design for 
selecting the working tool, orienting the die of the working tool, 
positioning the work piece in relation to the working tool and controlling 
and actuating the plunger means to impress the die onto the work piece, 
and repeating steps a to d until the design is impressed on the surface of 
the workpiece. 
The work piece can be composed of wax, leather, wood, or any compressible 
material. 
This invention is also directed to an apparatus wherein the first stepper 
motor means drives the turret to select a tool from a plurality of tools; 
the second stepper means orients the die of the working tool; a third 
stepper motor means drives a chuck holding the candle to position the 
candle rotationally in relation to the working tool said chuck being 
attached to a movable platform; a fourth stepper motor means for 
positioning the movable platform linearly in relation to the working tool; 
a solenoid means drives the design of the die onto the candle; and the 
computer means controls the stepper motors and solenoid. 
This invention is also directed to a turret apparatus having a planetary 
gear system which holds eight tools each having a die and each having a 
design on the die, however a turret holding any number of tools can be 
used.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIGS. 1, 2, 3 and 4, the candle 
decorating apparatus is shown. The apparatus consists of a digitizer 
tablet 62, a stepper motor controller and power supply , a power supply 
for the solenoid 4, a leadscrew driven translating bed 5, a candle 
supporting chuck 6 mounted on the translating bed which holds the candle 
8. The stamping machinery 7 is mounted on the machine's frame. Both the 
translating table and the stamping machinery are controlled by a computer 
loaded with the appropriate software to control the apparatus. The 
software is also essential for the programing of the design to be imparted 
on the candle. The components of my design in FIGS. 1, 2, 3 and 4 
comprise: 
60 Computer 
61 CRT 
62 Graphics Tablet or Digitizer Table 
2A Stepper motor leads 
2B Stepper motor leads 
2C Stepper motor leads 
2D Stepper motor leads 
2E Solenoid leads 
3 Stepper motor controller and power supply 
4 Solenoid power supply 
5 Translating Bed 
6 Candle chuck 
7 Stamping machinery cabinet 
8 Candle 
9 Motor for driving lead screw for the translating bed 
9A Candle rotation motor 
10 Lead screw for translating bed 
11 Vee slide for translating bed 
12 Bearing for lead screw 10 
13 Lead screw for stamping machinery for positioning elevation of stamping 
machinery 
14 Frame support for stamping machinery 
15 Positioning slide for the stamping machinery elevation 
17 Spacer disc 
18 Base Sprocket 
19 Sprocket attached to the tool change stepper motor 
20 Belt for driving tool change 
21 Fastener for bolting base assembly of stamping machinery holds inner 
bushing 22 to both the sprocket 18 and spacer 17 
22 Inner bushing 
23 Outer bushing 
24 Working tool shaft 
25 Non working tool shaft 
26 Working tool return spring 
27 Non working tool return spring 
28 Working tool planet gear 
29 Non working tool planet gear 
30 Sun gear (central gear) 
31 Sun gear shaft 
32 Angle change drive gear 
33 Tool change stepper motor 
34 Tool change stepper motor shaft 
35 Angle change stepper motor 
35A Angle change stepper motor shaft 
36 Working tool 
37 Non working tool 
38 Fastener 
39 Solenoid support 
40 Solenoid 
42 Solenoid plunger shaft 
43 Solenoid plunger tip 
44 Working tool sleeve bushing 
45 Non working tool sleeve bushing 
In the preferred embodiment of this machine the tooling is stationary and 
the workpiece (e.g.) the candle, is positioned linearly and/or angularly 
under the tooling. 
Linear positioning of the candle 8 is accomplished through the leadscrew 
driven translating bed. The candle translation motor 9 drives the bed 
through an anti-backlash leadscrew assembly 10. Because operational forces 
on the bed are strickly downward, a Vee arrangement is a convenient slide 
type. Preferably, the Vee is able to compensate so that transverse freedom 
cannot develop with wear, and is able to shed wax chips that occasionally 
fall from the candle during the decoration process. 
High accuracy and resolution of the positioning components are important to 
assure the attractiveness of the candles. The smallest mark applied is 
less than one tenth of an inch in diameter, and is used to define the 
outline of leaves, and to fill areas between larger marks that are close 
together. Because the attractiveness of a candle is significantly 
decreased if the small marks are poorly applied, the use of antibacklash 
components is advantageous. 
The machine is designed to decorate flat bottomed and topped candles 
ranging preferably from two to six inches in diameter and three to fifteen 
inches in length although thinner and/or longer candles can be used. It is 
preferable when longer candles are used to use a candle having a diameter 
of at least 3 inches. The requirements imposed on the chucking system 
include securely holding any of these candles while allowing the entire 
length of the candle to be exposed to stamping. The chuck 6 is also 
responsible for driving the rotation of the candle while not causing wax 
to crumble or crack. 
The system of chucking in the preferred embodiment consists of compressing 
the candle between flat plates, each of which have small spikes to press 
into the candle. To insure against cracking the ends of the candle, the 
spikes are pointed, short, of small diameter, and positioned far from the 
edge of the candle. The plates are the same diameter, or smaller, as the 
candle to be decorated to allow tools to access all of the candle without 
hitting the chuck plates. The chuck is adjustable to accomodate the 
various length candles. 
The functions performed by the stamping machinery include selecting. 
orienting, guiding and stamping the desired tool onto the surface of the 
candle at the location selected by the positioning system. A multi-tool 
and preferably an eight tool planetary gear system turret controlled by 
two stepper motors performs the selecting, orienting, and guiding 
operations. A linear solenoid provides the stamp. An adjustable support 
structure solidly positions the turret above any of the different diameter 
candles. Cabinetry provides protection for the machinery and the user. 
Angle change when referred to herein means the rotation about the vertical 
axis Z of the tool shaft 24 to orient non-circular designs on the tip of 
the tool for impression on the candle. 
The design of the turret and solenoid arrangement is illustrated in FIG. 2. 
The tools, which can be custom shaped out of the tool blanks are each 
threaded and fastened onto a tool shaft. Working tool shaft 24 passes 
through a sleeve bushing 44 and the base sprocket 18. In operational 
connection to the top of shaft 24 is a planet gear 28 which is in 
operative engagement with the sun gear 30. The tool angle change stepper 
motor 35 also has a gear 32 engaged with the sun gear. A stepped bushing 
is bolted directly to the base sprocket and spacer assembly. An outer 
bushing contains a ledge that catches beneath the step of the inner 
bushing and is bolted to an overhead support plate. The inner bushing and 
the components bolted to it are supported vertically by the outer bushing 
23 but are free to rotate about a central vertical axis. The solenoid 40 
is supported by a vertical plate 39 above the tool in the "working 
position" of the turret. The working tool 36 is the only tool which can be 
stamped at any one time. 
The events to make a mark on a candle 8 are as follows. While the 
positioning system selects the right location of the candle 8 to be 
beneath the working tool, the turret selects and orients the working tool 
36. A belt 20 is fitted around the base sprocket and is driven by the tool 
change stepper motor 33. When the tool change motor actuates, the chain 
causes the base sprocket and inner bushing assembly to rotate in the outer 
bushing. The working tool is selected in this manner. To adjust the angle 
of the working tool about its vertical axis, the angle change stepper 
motor rotates the sun gear and consequently all of the tool assemblies 
within their sleeve bushings. Once the candle 18 is positioned and the 
correct tool is selected and oriented, the shaft of the solenoid 42 
impacts the top of the working tool assembly. Contact is made with the tip 
43 of the solenoid plunger shaft. The working tool shaft 24 slides through 
its sleeve until the tool makes contact with the candle 18. Following the 
impact, the compression spring and a spring inside the solenoid return the 
system to the original positioning. The cycle is ready to repeat. 
The stamping machinery accomplishes complete control over the tools with 
just two motors and no linear slides as a result of several attributes. 
First, several of the components of the turret are multifunctional. 
Second, the linking of all the tools in a planetary gear train allows each 
rotational motion to have the identical affect on all eight tool 
assemblies. It is because of this coupling of motions that stored data 
needed for control is also minimized. Just two numbers are stored for each 
mark in the design data file to completely define the location and 
orientation of each of the eight tools in the turret. Finally, although 
the selection or reorientation of the working tool affects all tools 
equally, the turret is designed so that selection of a new tool does not 
affect the orientation value stored in the data file, and reorientation of 
the tools does not affect the selection value stored. By coupling motion 
of the eight tools together, while keeping the type of motion (selection 
or orientation) independant, hardware, software and storage requirements 
are minimized. 
One of the multifunctional parts and the heart of this system is the sun 
gear 30. As already mentioned, the primary role of this gear is to adjust 
the angle of the working tool 36. This gear also maintains the orientation 
of the tool 24 during its motion toward the candle. The sun gear teeth 
serve as guides to the sliding planet gear 28 during this motion. By 
adjusting the angles of all of the tools simultaneously, the sun gear 
makes file-management in the programs considerably easier. Instead of 
tracking eight angles, the programs only need to track one. An integer 
three to one ratio between the number of teeth on the sun and the planet 
gears was chosen to make the data-handling additionally easier. When tools 
are changed, the sun gear 30 is locked by the angle change stepper motor 
and the planet gears roll around the sun gear. By having an integer ratio 
and controlling the initial angle of all the tools at assembly, the new 
working tool arrives at the same angle as the previous working tool 
regardless of the direction of turret rotation. Consequently, the programs 
only record an angle change when the angle change motor actuates but not 
when the tool selection motor actuates. Although the angles and selection 
of the eight tools is controlled simultaneously by the two motors, the 
information needed for control remains uncoupled. 
Another multifunctional component of the turret is the inner thrust 
bushing. In addition to providing thrust and radial support while allowing 
rotational freedom, the bushing secures the sleeve bushings in place and 
provides seats for the return springs. Although the sleeves are pressed 
into the spacer to insure their vertical orientation, the possibility that 
they can work loose from the shocks of operation is present if no positive 
stop is used. The holes in the bushing are large enough for the springs to 
seat in, yet small enough to partially cover the flanges of the sleeves. 
By providing seats for the springs and by selecting springs with large 
enough inside diameters to provide clearance around the shafts, friction 
losses due to the spring wire rubbing against the tool shaft is avoided. 
The outer thrust bushing supports the turret from the overhead support 
frame and acts as a protective casing for the turret machinery. The length 
of the bearing surfaces is as long as possible under the geometric 
constraints present in order to reduce the coefficient of friction and the 
maximum angle that can be present between the centerlines of the two 
bushings. Should a large angle be present, an error would occur in the 
location of marks on the candle. 
The solenoid 40 is selected to produce enough tool impact energy for any of 
the marks to obtain the desired size and whiteness from the resulting 
stress cracks. Several mechanisms are used to control the depth and 
quality of each mark individually. Delay loops in the control program 
allow the full thrust of the solenoid 40 to develop before the voltage is 
removed from the windings. The program uses a longer delay loop for the 
largest area marks than for the smaller marks. The smallest mark uses no 
delay loop at all. To further control the depth of the smallest mark, a 
stiffer return spring 26 can be used than for the other tools. For the 
largest marks, the machine can be programmed to strike multiple times at 
the same location to increase the area and depth of the mark. Finally, 
variable voltage supply 4 powers to the solenoid 40. Smaller marks are 
applied with a lower voltage than the larger marks as a further control of 
the depth of indentation. 
The control software system (which is more particularly described in my 
disertation for the degree, Master of Mechanical Engineering at Bucknell 
University files in the Bucknell University Library, Bucknell University, 
Pennsylvania, September 1986, is as follows: 
The control software system is comprised of four main operational programs 
and a menu driven software control program that interfaces with the user 
from the time the computer is activated. 
The first operational program accepts entry of the geometric information 
from the digitizer that defines the desired candle design and provides a 
graphical verification of the data as it is entered to the digitizer. To 
reproduce a hand decorated design, the user must wrap a piece of paper of 
dimensions equal to the length by the circumference of the candle around 
the candle. Pressing a pencil lead over the paper covered candle will 
transfer candle mark shapes and their locations to the paper. The paper is 
laid on the digitizer tablet. The data entry program will accept the 
information to describe the design. The user touches the electronic pen of 
the digitizer to the center of each mark. The computer records the 
coordinates of the mark in a data file record along with a mark number 
(corresponding to a tool location in the turret) and a mark angle as 
entered through keystroke entries. Once all marks have been touched, the 
geometric data file describing the design is completed. The process can be 
altered using a desired paper design that has never been hand decorated. 
The second program organizes the data into the order the machine will apply 
the marks to the candle and, using calibration factors, computes the 
number of motor steps each motor must make to locate and apply each of the 
marks of the design. A data file with this motor step information is 
stored for the design and is used each time the machine is run to apply 
that design to a candle. 
The third program calls upon the motor step data file for a desired design 
and controls the operation of the machine during the application of the 
design. 
The fourth and final program provides a graphical verification should the 
user wish to see on the CRT a design that has been entered. 
My method is equally applicable for inscribing a design into leather and 
plastics. The time required to impart a design of about 1500 marks over 
the surface of a 9 inch candle with diameter of 3 inches is about 20 
minutes. 
There is disclosed several embodiments according to the invention. It will 
be obvious that changes and variations can be made thereto without 
departing from the spirit of the invention which is limited only by the 
scope of the claims annexed hereto: