U.S. patent application number 09/725385 was filed with the patent office on 2001-03-15 for planocentric gear for amperage indicator on welding machine.
Invention is credited to Peters, Mark E..
Application Number | 20010000009 09/725385 |
Document ID | / |
Family ID | 22609094 |
Filed Date | 2001-03-15 |
United States Patent
Application |
20010000009 |
Kind Code |
A1 |
Peters, Mark E. |
March 15, 2001 |
Planocentric gear for amperage indicator on welding machine
Abstract
A shunt controlled welding machine has a regulator handle and a
scale that indicates output amperage on the same panel of the
welding machine case. The handle attaches to a shaft that rotates
about an axis of rotation to move a shunt into and out of a
transformer. The handle is part of a planocentric gear. Teeth on an
indicator mesh with teeth on a pinion that is fixed to the case
panel. By turning the handle, the indicator orbits and slowly
revolves about the shaft axis of rotation. The indicator has a
pointer that indicates the welding machine output amperage on the
scale.
Inventors: |
Peters, Mark E.; (Menasha,
WI) |
Correspondence
Address: |
Donald Cayen
Suite 501
104 South Main Street
Fond du Lac
WI
54935
US
|
Family ID: |
22609094 |
Appl. No.: |
09/725385 |
Filed: |
November 29, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09725385 |
Nov 29, 2000 |
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09167850 |
Oct 7, 1998 |
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Current U.S.
Class: |
219/136 |
Current CPC
Class: |
B23K 9/32 20130101 |
Class at
Publication: |
219/136 |
International
Class: |
B23K 009/10 |
Claims
I claim:
1. A planocentric gear for a welding machine having a case and a
transformer comprising: a. a shaft rotatable about an axis of
rotation and in operative association with a shunt to move the
shunt in relation to the transformer and thereby regulate the
machine output amperage in response to rotation of the shaft; b. a
pinion fixed to the machine case and having a first number of gear
teeth that are concentric with the shaft axis of rotation; c. a
handle attached to the shaft, the handle having an annular surface
that is eccentric to the shaft axis of rotation; and d. an
indicator captured between the machine case and the handle, the
indicator having an outer diameter that engages the handle annular
surface and a second number of teeth greater than the first number
and in mesh with the pinion teeth, the indicator revolving about
the shaft axis of rotation in response to and in proportion to
turning of the handle to provide an indication of the welding
machine output amperage.
2. The planocentric gear of claim 1 wherein: a. the case includes a
scale concentric with the shaft axis of rotation and bearing
indicia representative of the welding machine output amperage; and
b. the indicator includes a pointer that revolves around the shaft
axis of rotation to indicate the welding machine output amperage on
the scale in response to turning the handle.
3. The planocentric gear of claim 1 wherein the number of indicator
teeth is one greater than the number of pinion teeth.
4. The planocentric gear of claim 1 wherein the indicator makes
less than one revolution about the shaft axis of rotation for a
full range from minimum to maximum output amperage of the welding
machine.
5. A shunt controlled welding machine comprising: a. a case having
a panel; b. a transformer and a shunt inside the case; c. a shaft
extending through the panel and defining an axis of rotation, the
shunt moving relative to the transformer in response to rotating
the shaft to thereby regulate the output amperage of the welding
machine; d. a generally circular scale imprinted on the panel
concentric with the shaft axis of rotation and calibrated with the
welding machine output amperage; and e. means for indicating on the
scale the welding machine output amperage.
6. The welding machine of claim 5 wherein the means for indicating
on the scale the welding machine output amperage comprises: a. a
pinion fixed to the panel and having a predetermined number of
teeth; b. a handle attached to the shaft; and c. an indicator
having teeth meshing with the pinion teeth and revolving about the
shaft axis of rotation in proportion to the turning of the shaft,
the indicator indicating on the scale the welding machine output
amperage.
7. The welding machine of claim 6 wherein the indicator revolves a
distance of one tooth on the pinion for every complete turn of the
shaft.
8. The welding machine of claim 6 wherein the indicator makes less
than one full revolution around the shaft axis of rotation in
response to the shaft turning sufficiently to regulate the welding
machine between minimum and maximum output amperages thereof.
9. In a welding machine having a case with a transformer and a
shunt that cooperate to produce output amperages over a range from
minimum to maximum: a. regulator means for moving the shunt
relative to the transformer and thereby regulating the welding
machine output amperage, the regulator means comprising: i. a shaft
defining an axis of rotation and extending through the case
selected panel, the shaft coacting with the shunt to regulate the
welding machine output amperage in response to rotation of the
shaft; and ii. a handle attached to the shaft for rotating the
shaft and thereby regulating the welding machine output amperage;
and b. indicia on a selected panel of the case representative of
the welding machine output amperage, the indicia being arranged on
the selected panel in a generally circular shape and concentric
with the shaft axis of rotation.
10. The welding machine of claim 9 wherein the regulator means
further comprises gear means for cooperating with the indicia on
the case selected panel to indicate the welding machine output
amperage.
11. The welding machine of claim 10 wherein the gear means
comprises: a. a pinion fixed to the case selected panel; and b. an
indicator meshing with the pinion and revolving about the shaft
axis of rotation in response to turning the handle, the indicator
cooperating with the indicia on the case selected panel to indicate
the welding machine output amperage.
12. The welding machine of claim 11 wherein the indicator makes
less than one revolution in response to the handle turning
sufficiently for the welding machine to produce a range of output
amperages from minimum to maximum.
13. The welding machine of claim 11 wherein: a. the pinion has a
first number of teeth, and wherein the indicator has a second
number of teeth one more than the first number; and b. the
indicator revolves around the indicia on the case selected panel a
distance of one pinion tooth for every turn of the handle.
Description
1. This is a divisional application of U.S. patent application Ser.
No. 09/167,850 filed Oct. 7, 1998.
BACKGROUND OF THE INVENTION
2. 1. Field of the Invention
3. This invention pertains to welding machines, and more
particularly to apparatus that manually regulates and visually
indicates the output amperage of shunt controlled welding
machines.
4. 2. Description of the Prior Art
5. The output of some welding machines is regulated by a shunt that
moves into and out of a transformer inside the welding machine
case. The shunt is typically designed to be moved by a screw and
nut arrangement. One end of a shaft protrudes through a first case
panel and has a crank attached to it. The other end of the shaft
has threads that mate with a nut on the shunt. Manually turning the
crank causes the shunt to move linearly within the case. Examples
of prior welding machines that employ a shunt and crank regulating
system may be seen in U.S. Pat. Nos. 5,639,392 and 5,660,749. A
generally similar welding machine is manufactured by Miller
Electric Company, Appleton, Wis., under the trademark
Thunderbolt.
6. To determine the shunt position relative to the transformer, and
thus indicate the welding machine output amperage, it is known to
include a wiper that is attached to the shunt. The wiper moves
linearly inside the welding machine case with the shunt in response
to turning the crank mounted on a shfat protruding from a first
panel of the machine case. An elongated opening through a second
panel of the machine case at a right angle to the first panel
enables a person to see the wiper position. A scale on the outside
of the case second panel adjacent the opening provides correlation
between the shunt position and the welding machine output.
7. In another shunt controlled welding machine, there is an
elongated rectangular opening in the same panel through which the
crank shaft protrudes. The opening is at some distance from the
crank. A long flexible band is attached at one end to the shunt and
at a second end to a spring. In turn, the spring is connected to a
stationary part of the welding machine. Manually turning the crank
causes the shunt to move and also causes the band to slide within
the opening. The band is marked in a manner that cooperates with a
linear scale adjacent the opening to indicate the welding machine
output in relation to the shunt position. An example of a prior
shunt controlled welding machine having a crank and linearly moving
indicator band on the same panel is a machine manufactured by
Miller Electric Company, Appleton, Wis., under the trademark Econo
Twin.
8. The prior shunt controlled welding machines provide excellent
performance at an economical cost. Nevertheless, it is desirable
that the mechanism for indicating the welding machine output be
further developed.
SUMMARY OF THE INVENTION
9. In accordance with the present invention, a planocentric gear is
provided that indicates the output amperage of a shunt controlled
welding machine. This is accomplished by apparatus that includes a
high gear reduction between a turnable handle and a revolving
pointer.
10. The welding machine has a transformer inside a case. A shunt
includes a threaded block. Threads on one end of a shaft mate with
the block threads. The other end of the shaft extends through a
panel of the case. Attached to the shaft outside of the case panel
is the handle. By turning the handle, the shaft rotates to linearly
move the shunt into greater or lesser engagement with the welding
machine transformer.
11. The handle is formed with an annular recess partially defined
by a hub external surface and by an internal annular surface. The
hub external surface is concentric with the axis of rotation of the
shaft. The handle internal annular surface is eccentric to the
shaft axis of rotation.
12. Fixed to the case concentric with the shaft axis of rotation
and within the handle recess is a pinion. Around the pinion outer
diameter are a number of teeth. An inner diameter of the pinion
loosely pilots over the hub external surface of the handle.
13. The planocentric gear further comprises an indicator that is
also within the handle recess. The indicator has an outer diameter
that fits with a running clearance inside the eccentric internal
annular surface of the handle. The indicator also has a number of
internal teeth that are concentric with the indicator outer
diameter. The indicator teeth mesh with the pinion teeth. The
indicator has at least one more tooth than the pinion. The pointer
is part of the indicator and is outwardly directed from an outer
periphery of the indicator. A scale is imprinted on the welding
machine case around the shaft axis of rotation. The scale is
calibrated to correlate welding machine output amperage with the
position of the indicator pointer.
14. In operation, the welding machine operator turns the handle to
obtain the desired output amperage from the welding machine.
Turning the handle causes its eccentric internal annular surface to
force the indicator to orbit about the shaft axis of rotation.
Superimposed on the indicator orbiting is a revolving of the
indicator about the shaft axis of rotation in the same direction as
the handle turning, but at a much slower speed. Specifically, for
each complete turn of the handle and corresponding complete orbit
of the indicator, the indicator undergoes a partial revolution by
advancing one tooth on the pinion. The indicator pointer thus
revolves in proportion to the handle turns and indicates the
welding machine output amperage from the scale imprinted on the
case.
15. The method and apparatus of the invention, using a planocentric
gear, thus provides a very economical way to indicate output
amperage of a shunt controlled welding machine. The planocentric
gear is on the same machine panel as the handle, thereby improving
accessibility to and versatility in placement of the welding
machine.
16. Other advantages, benefits, and features of the present
invention will become apparent to those skilled in the art upon
reading the detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
17. FIG. 1 is an exploded view of a typical shunt controlled
welding machine that includes the present invention.
18. FIG. 2 is an exploded view of the invention.
19. FIG. 3 is a longitudinal cross sectional view of the
invention.
20. FIG. 4 is a cross sectional view on an enlarged scale taken
along line 4--4 of FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
21. Although the disclosure hereof is detailed and exact to enable
those skilled in the art to practice the invention, the physical
embodiments herein disclosed merely exemplify the invention, which
may be embodied in other specific structure. The scope of the
invention is defined in the claims appended hereto.
22. Referring to FIGS. 1 and 2, a typical shunt controlled welding
machine 1 is illustrated that includes the present invention. The
output amperage of the welding machine 1 is regulated by turning a
handle 3. Turning the handle 3 rotates a shaft 5. The shaft 5 has
threads 7 on one end that mate with threads in a shunt block 6
inside the welding machine case 9. By turning the handle, the shunt
block 6 moves into and out of a transformer 10 inside the welding
machine case 9 to regulate the welding machine amperage output.
23. In accordance with the present invention, a planocentric gear
11 indicates the output amperage of the welding machine 1. The
planocentric gear 11 includes a pointer 13 that revolves in
proportion to the turns of the handle 3. The pointer 13 indicates
the output amperage as printed on a circular scale 15 on a panel 12
of the welding machine case 9.
24. The planocentric gear 11 is comprised of the handle 3, an
indicator 17, and a pinion 19. The pinion 19 is fixed to the panel
12 of the welding machine case 9. External gear teeth 21 on the
pinion mesh with internal teeth 61 on the indicator 17. The handle
is attached to the shaft 5 by a screw 25 with the indicator and the
pinion lying in a recess between the handle and the panel 12.
Turning the handle in the direction of arrow 27 in FIG. 2 causes
the indicator to revolve in the same direction 29.
25. The shaft second end is rotatably supported in an opening 29 in
the welding machine panel 12, FIG. 3. The shaft second end
preferably has an external hex 31. The handle 3 has an internal hex
33 that receives the hex end 31 of the shaft 5. The screw 25 passes
through a clearance hole 35 in the handle and into a tapped hole 36
in the shaft second end. The shaft is thus captured in the welding
machine 1 for rotation about an axis 37. An end surface 38 of the
handle has sliding clearance with the machine panel 12.
26. The handle 3 is further constructed with a hub having an
external surface 39 that is concentric with the shaft axis of
rotation 37. The hub external surface 39 terminates in a flat
radial surface 41. The radial surface 41 ends at an internal
annular surface 43. The interior annular surface 43 has a
centerline 45 that is eccentric to the axis of rotation 37 by a
distance E. Also see FIG. 4. There is an arm 47 on the handle. On
the free end of the arm 47 is a hand grip 49.
27. In the illustrated construction, the indicator 17 is captured
between the machine panel 12 and a handle recess that is partially
defined by the internal annular surface 43 and the radial surface
41. The indicator has an inner diameter 55 that has adequate
diametrical clearance with the handle hub external surface 39. The
indicator also has an outer diameter 57 that engages the hub
internal annular surface 43 with a running clearance. The indicator
outer diameter 57 is thus concentric with the eccentric centerline
45. Undercut from the indicator inner diameter 55 is a radial
surface 59 that ends at internal gear teeth 61. The gear teeth 61
are concentric with the indicator outer diameter 57 and thus are
concentric with the handle eccentric centerline 45. The gear teeth
61 have a very high pressure angle, such as 55 degrees. A diametral
pitch of 22 for the teeth is satisfactory. Opposite the teeth is an
outer periphery 63. The pointer 13 projects outwardly from the
indicator outer periphery 63.
28. The pinion 19 is fixed to the case panel 12. For example, the
pinion may have a pair of integral pins 65 that tightly fit into
corresponding holes 67 in the machine panel. The pinion has an
inner diameter 69 that has a running clearance with the handle hub
external surface 39. The outer periphery of the pinion has a number
of gear teeth 71. The pinion teeth 71 are concentric with the
pinion inner diameter 69 and are thus concentric with the shaft
axis of rotation 37. The pinion teeth 71 mesh with the indicator
teeth 61.
29. The number of indicator teeth 61 is at least one greater than
the number of pinion teeth 71. In a particular embodiment of the
invention, there are 35 teeth on the indicator 17 and 34 teeth on
the pinion 19. The difference in the number of teeth, together with
the eccentricity E of the indicator and pinion, result in the
indicator and pinion teeth being in complete mesh with each other
only at a point represented by letter A, which is on the opposite
side of the axis of rotation 37 as the eccentric centerline 45. At
the same time, the indicator and pinion teeth at the point
represented by letter B, which is on the same side of the axis of
rotation 37 as the eccentric centerline 45, are completely out of
mesh with each other.
30. In operation, the planocentric gear 11 is assembled such that
the pointer 13 is at a location on the scale 15 that represents a
minimum output amperage of the welding machine 1. The planocentric
gear is timed with the position of the shunt block 6 relative to
the machine transformer 10 such that the corresponding minimum
amount of output amperage is actually produced. Turning the handle
3, as in the direction of arrow 27, causes the shaft 5 to move the
shunt block 6 out of the transformer 10 and thus increase the
machine output amperage. Simultaneously, the indicator pointer
revolves in the direction of arrow 29, but at a much lesser amount.
Indicator revolving is caused by the engagement of the handle
eccentric internal annular surface 43 with the indicator outer
diameter 57. As the handle turns, the eccentric annular surface 43
progressively forces the indicator to orbit in a circle around the
shaft axis of rotation 37. The indicator makes one orbit for each
turn of the handle. Simultaneously with the indicator orbiting
about the axis of rotation 37, the point A of complete meshing
between the indicator teeth 61 and the pinion teeth 71 advances
around the pinion teeth in proportion to and in the same direction
as the indicator is orbiting. Consequently, the indicator revolving
about the axis of rotation 37 by advancing around the pinion teeth
is superimposed on the indicator orbiting. For a pinion 19 having
34 teeth and an indicator 17 having 35 teeth, the indicator
advances one tooth on the pinion for every turn of the handle.
Thirty-four turns of the handle thus result in one revolution of
the indicator.
31. The scale 15 is calibrated to read the machine output amperage
as a function of the shunt block position. With commercially
acceptable embodiments of the welding machine 1, less than 34 turns
of the handle 3 are used to produce the full range from minimum to
maximum machine output amperage. Accordingly, the indicator pointer
13 makes less then one complete revolution over the full operating
range of the welding machine.
32. Thus, it is apparent that there has been provided, in
accordance with the invention, a planocentric gear for amperage
indicator on a welding machine that fully satisfies the aims and
advantages set forth above. While the invention has been described
in conjunction with specific embodiments thereof, it is evident
that many alternatives, modifications, and variations will be
apparent to those skilled in the art in light of the foregoing
description. Accordingly, it is intended to embrace all such
alternatives, modifications, and variations as fall within the
spirit and broad scope of the appended claims.
* * * * *