Abstract
A multi-tool process station includes a tool sub-station having a
plurality of electrically powered tools moveable between an operating
position and a ready position; a voltage source spaced therefrom by
a distance; at least one controller spaced from the tool sub-station
and in communication with the tools; a cable structure extending across
the distance and having not more than one outer cable sheath at any
point along the distance, the cable structure supplying power from
the voltage source to a plurality of the tools and further carrying
control signals to the plurality of tools. The cable structure may
consist of a single continuous cable, or may comprise multiple cable
segments, such as first and second cables connected in series. The
tool sub-station may be disposed proximate a vehicle manufacturing
line and the plurality of tools comprise at least a plurality of screw
spindles.
Claims
What is claimed is:
1. A multiple tool processing assembly, comprising: a tool sub-station
having a plurality of electrically powered tools disposed thereat,
said tools moveable between an operating position and a ready position;
a voltage source distinct from said sub-station and spaced therefrom
by a distance; at least one controller spaced from said tool sub-station
and in communication with said tools; a cable structure extending
across said distance and having not more than one outer cable sheath
at any point along said distance, said cable structure supplying
power from said voltage source to said plurality of said tools and
further carrying control signals, from said controller, to said
plurality of tools.
2. The assembly of claim 1 wherein said cable structure consists
of a single continuous cable.
3. The assembly of claim 1 wherein said cable structure comprises
first and second cables connected in series.
4. The assembly of claim 3 wherein said second cable is more flexible
than said first cable.
5. The assembly of claim 3 wherein said second cable is detachably
connected to said first cable.
6. The assembly of claim 1 wherein said cable structure terminates
directly at a first one of said plurality of tools.
7. The assembly of claim 1 wherein said plurality of tools are
connected in electrical series to said cable structure.
8. The assembly of claim 7 further comprising a termination plug
connected to said cable structure with said plurality of tools electrically
therebetween.
9. The assembly of claim 1 wherein said tool sub-station comprises
a distribution block, and wherein said distribution block is electrically
disposed between said cable structure and said plurality of tools.
10. The assembly of claim 1 wherein said cable structure comprises
multiple conductors in a common sheath.
11. The assembly of claim 10 wherein said multiple conductors are
selected from the group consisting of electrical conductors and
optical conductors.
12. The assembly of claim 10 wherein said cable comprises at least
one conductor shielded from other conductors in said cable and suitable
for use in an ARCnet.
13. The assembly of claim 1 wherein said tool sub-station is disposed
proximate a vehicle manufacturing line and wherein said plurality
of tools comprise at least a plurality of screw spindles.
14. The assembly of claim 13 wherein said spindles each comprise
at least one measurement transducer and an address device.
15. The assembly of claim 1: wherein said cable structure terminates
directly at a first one of said plurality of tools and wherein said
plurality of tools are connected in electrical series to said cable
structure; wherein said tool sub-station is disposed proximate a
vehicle manufacturing line; and wherein said plurality of tools
comprise at least a plurality of screw spindles.
16. The assembly of claim 15 wherein said cable structure comprises
a flexible cable portion disposed proximate said plurality of tools.
17. The assembly of claim 1: wherein said tool sub-station comprises
a distribution block, and wherein said distribution block is electrically
disposed between said cable structure and said plurality of tools;
and wherein said cable structure terminates directly at said distribution
block wherein said tool sub-station is disposed proximate a vehicle
manufacturing line; and wherein said plurality of tools comprise
at least a plurality of screw spindles.
18. The assembly of claim 17 wherein said cable structure comprises
a flexible cable portion disposed proximate said plurality of tools.
19. The assembly of claim 1 wherein said plurality of tools comprise
at least a plurality of screw spindles and wherein said spindles
each comprise at least one measurement transducer and an address
device.
20. The assembly of claim 1 wherein said cable structure supplies
all the power to all of said plurality of tools.
21. A method of routing power and data to a plurality of electrically
powered tools of multi-tool process machine station, comprising:
positioning said plurality of tools at a tool sub-station so as
to be moveable between an operating position and a ready position;
providing a voltage source distinct from said sub-station at a location
spaced therefrom by a distance; providing at least one controller
in communication with said tools; routing all the power that is
used to power said plurality of tools from said voltage source to
said tool sub-station through a cable structure extending across
said distance and having not more than one outer cable sheath at
any point along said distance; and routing control signals, from
said controller, to said plurality of tools through said cable structure.
22. The method of claim 21 wherein said cable structure consists
of a single continuous cable.
23. The method of claim 21 wherein said cable structure comprises
first and second cables connected in series and together extending
across said distance, said second cable more proximate said tools
than said first cable.
24. The method of claim 23 wherein said second cable is more flexible
than said first cable.
25. The method of claim 23 further comprising detachably coupling
said second cable to said first cable.
26. The method of claim 21 further comprising terminating said
single cable structure directly at a first one of said plurality
of tools.
27. The method of claim 21 further comprising distributing power
to said plurality of tools through a daisy-chain connecting said
plurality of tools.
28. The method of claim 27 further comprising electrically connecting
a termination plug to said cable structure with said plurality of
tools electrically therebetween.
29. The method of claim 21 wherein said tool sub-station comprises
a distribution block, and further comprising disposing said distribution
block electrically between said cable structure and said plurality
of tools.
30. The method of claim 21 further comprising disposing said tool
sub-station proximate a vehicle manufacturing line and wherein said
plurality of tools comprise at least a plurality of screw spindles.
31. The method of claim 21 wherein positioning said plurality of
tools at a tool sub-station comprises positioning plurality of screw
spindle tools at a tool sub-station, said spindles each comprising
at least one measurement transducer and an address device.
Description
[0001] This application claims priority from European Patent Application
No. 04006868.6, filed on 22 Mar. 2004, which is incorporated herein
by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention generally relates to the control of
electrically powered manufacturing tools, and particularly relates
to the routing of power and data from a voltage source to the plurality
of electrically powered manufacturing tools of a tool sub-station
that is located a distance from the voltage supply in a multi-tool
process machine.
[0003] The use of various electrically powered machines to help
automate production processes such as welding, screwing, or similar
processes is well known in the art. Indeed, it is not uncommon for
such machines to employ multiple tools of this type. Such multiple
tool machines typically include a plurality electrically powered
tools which are supported at a so-called tool sub-station for movement
between an operation position and a storage or ready position; a
voltage source distinct from the tool sub-station and spaced therefrom
by a distance; and at least one controller. The controller typically
electrically connects with the voltage source via one or more cables,
and the voltage source typically electrically connects to each of
the numerous individual tools over corresponding plurality of individual
cables running therebetween. Indeed, it is common for the voltage
source to use at least two different and individual cables to connect
with each individual tool, meaning, for example, at least sixteen
cables are required for eight tools. Thus, there are a large number
of cables running from the voltage source to the tool sub-station
for the supply of power.
[0004] The wiring complexity associated with the prior art machines
described above adds cost to the machine, as each cable is typically
expensive, and also add significant complexity to the overall mechanical
structure to support the numerous cables. Further, the large number
of cables complicates installation and maintenance of the machines.
[0005] Thus, there remains a need for alternative approaches to
supplying power and data to electrically powered manufacturing tools
of a multi-tool process station.
SUMMARY OF THE INVENTION
[0006] The present invention provides a method of supplying power
and data to electrically powered manufacturing tools of a multi-tool
process station. The multi-tool process station of the present invention
includes a tool sub-station having a plurality of electrically powered
tools disposed thereat, the tools moveable between an operating
position and a ready position; a voltage source distinct from the
sub-station and spaced therefrom by a distance; at least one controller
spaced from the tool sub-station and in communication with the tools;
a cable structure extending across the distance and having not more
than one outer cable sheath at any point along the distance, the
cable structure supplying power from the voltage source to more
than one of said plurality of tools and further carrying control
signals from the controller to said more than one of said plurality
of tools. The cable structure may consist of a single continuous
cable, or may comprise multiple cable segments connected in series.
If there is more than one cable portion, the cable portion closest
to the tools is advantageously more flexible than the other portion(s)
of the cable structure, and is advantageously detachable. The cable
structure may terminate directly at a first one of the plurality
of tools, and the plurality of tools may be connected in electrical
series to the cable structure, advantageously with a termination
plug connected thereto with the plurality of tools electrically
between the cable structure and the termination plug. Alternatively,
the tool sub-station may comprise a distribution block, with the
distribution block electrically disposed between the cable structure
and the plurality of tools. The cable structure may comprise multiple
conductors in a common sheath, and the conductors may be selected
from the group consisting of electrical conductors and optical conductors.
For example, the cable may comprise at least one conductor shielded
from other conductors in the cable and suitable for use in an ARCnet.
The tool sub-station may be disposed proximate a vehicle manufacturing
line and the plurality of tools may comprise at least a plurality
of screw spindles. The spindles may each comprise at least one measurement
transducer and an address device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 shows a multi-tool process station according to one
embodiment of the present invention.
[0008] FIG. 2 shows a multi-tool process station according to another
embodiment of the present invention.
[0009] FIG. 3 shows a cross-section of a cable suitable as the
cable structure in the embodiment of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0010] FIG. 1 shows an exemplary multi-tool machine, sometimes
referred to herein as a multiple tool processing assembly or multi-tool
process station, generally referred to at 10. The multi-tool machine
10 of FIG. 1 includes a tool sub-station 40, a voltage source 20,
a controller 30, and one or more cables 32, 62. For the sake of
clarity, the tool sub-station 40, voltage source 20, and controller
30 are merely generally described below, with details thereof only
added where necessary to aid in understanding the present invention;
such devices are generally known and understood in the art. The
tool sub-station 40 typically includes a cabinet 42 or other frame
that supports a plurality of tools 44 for movement between an operating
position 46u (e.g., down) and a storage or ready position 46r (e.g.,
up). Typically, the tools 44 are detachably mounted to a so-called
screw plate 48, with the screw plate 48 moving vertically up and
down to move the various tools 44 up and down in unison. The tools
44 are electrically powered and may take any form known in the art
such as screw spindles, welders, or the like. It should be noted
that the tools 44 may advantageously include appropriate address
means 45, such as rotary switches, for setting the address for each
tool if the tools 44 are be controlled via addressed signals. The
individual tools 44 may also include measurement transducers 45d,
gear drives, measuring electronics, motors, and the like, as needed
or desired. In addition, the individual tools 44 may have straight,
offset, or angled drive outputs, as needed or desired. The tool
sub-station 40 is typically located proximate an assembly line 12,
such as a vehicle assembly line.
[0011] The voltage source 20 supplies the necessary voltages to
power the tools 44. The voltage source 20 may provide a single voltage,
such as 24 VDC, or a plurality of voltages such as 380 VDC and 24
VDC depending on the type and number of tools 44. As is known in
the art, the voltage source 20 may optionally include a braking
chopper which is designed for a fixed or varying cycle time, a turn-on
current limiting device, a voltage monitoring device with switch-off
at prescribed minimum and/or maximum voltage values, a temperature
monitoring device, heat sinks, a mains filter, a mains connection,
a main switch, a main contactor, operating signal lamps, an emergency-stop
device, and similar devices. The voltage source 20 may further be
advantageously housed in a suitable module housing 22, and be mountable
in a variety of ways, including via mounts that also function as
heat sinks. As shown in FIG. 1, the voltage source 20 is spaced
from the tool sub-station 40 by distance X, with this distance spanned
by a cable structure 60, discussed further below.
[0012] Controller 30 controls the overall operation of the machine
10. The controller 30 is typically housed in a cabinet 34 or the
like at some distance from the tool sub-station 40. The controller
30 may be located away from the voltage source 20, or co-housed
therewith (see FIG. 2), as is desired. The controller 30 may connect
to the voltage source 20 via a cable 32 or other means for carrying
power and/or data therebetween. Further, the connection between
the controller 30 and the voltage source 20 for the flow of data
one or both ways may be via a wireless connection, such as an RF
link, if desired.
[0013] The voltage source 20 supplies power to the tool sub-station
40 so as to enable the tools 44 to function. In the present invention,
the power for a plurality of the tools 44, and optionally all the
tools 44, is routed through the cable structure 60 that extends
across the distance X separating the voltage source 20 and the tool
sub-station 40. Typically, this cable path 60 takes the form of
a single continuous cable 62, but the cable structure 60 may alternatively
take the form of a plurality of cable sections connected in series.
For example, the cable structure 60 may have a first portion 62
that spans the majority or totality of distance X, and a second
flexible cable portion 50 detachably connected to the first portion
62 so as to be more proximate to the tools 44. It should be understood
that the term "cable," as used herein, refers to a collection
of one or more conductors 64 that share a common cable sheath 68
along substantially all of the relevant portions of their length,
regardless of their configuration (e.g., layered, twisted, side-by-side
duplex, etc.) within the common cable sheath 68. It should be noted
that the conductors 64 may be of any type known in the art, such
as common copper wires or optical fibers.
[0014] The cable structure 60 may advantageously extend beyond
its first mechanical connection to the tool sub-station 40 so that
the cable structure 60 terminates at one of the tools 44. Alternatively,
the cable structure 60 may terminate at a distribution box 52 that
forms part of the tool sub-station 40. In any case, the connection
to the cable structure 60 may be relatively permanent, or may advantageously
be made using suitable connectors that allow the cable structure
60 to be disconnected when desired, such as for purposes of repair
or replacement. Indeed, all the data and power connections in the
machine 10 may be made in a permanent fashion, or advantageously
through appropriate detachable connections (e.g., plug connectors,
etc.).
[0015] Data, such as commands and other instructions from the controller
30 are also routed through the cable structure 60. As such, the
cable structure 60 may include suitably shielded conductors 66 for
carrying data signals network communications, especially LAN communications,
such as an ARCnet LAN. The tools 44 should include appropriate electronics
to separate data from power.
[0016] As pointed out above, the cable structure 60 from the voltage
source 20 may terminate at a distribution box 52 in the tool sub-station
40. With such an arrangement, the individual tools 44 may then be
connected to the distribution box 52 by respective flexible cables
50t. Alternatively, the cable structure 60 may terminate at a first
tool 44 in the tool sub-station 40, with one or more other tools
44 connecting thereto in a daisy-chain fashion. Such a daisy-chain
may be open ended or close ended (e.g., a ring). It should be note
that the chain may advantageously terminate in a simple termination
plug 69, or in an over-voltage protection device if desired. The
termination plug may be removed from one tool and added to another
when adding or deleting tools 44 to the daisy-chain.
[0017] By way of example, FIG. 1 shows a multi-tool machine 10
according to one embodiment of the present invention with the voltage
source 20 separate from the controller 30, the cable structure 60
including a flexible cable 50, and the flexible cable 50 terminating
at a tool 44, with the tools 44 connected in a daisy-chain. In the
embodiment of FIG. 1, the first cable portion 62 forming the distal
portion of cable structure 60 is typically installed relatively
permanently, and sometimes referred to as a field cable. Such a
field cable 62 will generally be less expensive than the corresponding
flexible cable 50, which will generally be more expensive due to
the additional flexibility and environmental requirements placed
thereon. FIG. 2 shows another multi-tool machine 10 according to
another embodiment of the present invention with the voltage source
20 and the controller 30 in a common cabinet, the cable structure
60 terminating at distribution box 52, and the individual tools
44 connecting to the distribution box 52 by respective flexible
cables 50t in a fan-out arrangement. Once again, the field cable
62 forming a portion of the cable structure 60 will typically be
less expensive than the multiple flexible cables 50t connecting
the distribution box 52 to the tools 44 due to the flexibility and
environmental requirements on the flexible cables 50t.
[0018] By supplying power and data signals to more than one tool
44 through a common cable structure 60, the costs of installing
and maintaining the multi-tool machine 10 are greatly reduced. For
instance, the control electronics for multiple tools 44 may be combined
into a common controller 30, rather than having to have a separate
controller 30 for each tool 44. Further, as the number of cables
is reduced, the amount of cable breakage electronics and associated
maintenance can be reduced.
[0019] In preferred embodiments, the multi-tool machine 10 will
have only a single cable structure 60 extending from the voltage
source 20 to the tool sub-station 40 that supplies all the power
and data for all the various tools 44. As used herein, the terms
"single cable structure" or "not more than one cable
structure" exclude the use of multiple cables in parallel,
but allow any number of cables to be used in series. In other embodiments,
such as where the number of tools 44 is quite high or the power
consumption of the tools 44 is high, the multi-tool machine 10 may
have more than one cable structure 60 extending between the voltage
source 20 and the tool sub-station 40, with at least one cable structure
60 supplying power and data to more than one tool 44.
[0020] While the discussion above has been in terms of a dedicated
controller 30 and voltage source 20 for a given tool sub-station
40, the approach of the present invention may also be used where
more than one tool sub-station 40 is connected to a given voltage
source 20 (via separate cable structures 60), and/or where a given
controller 30 controls more than one tool sub-station 40, or a combination
thereof.
[0021] Additionally, those skilled in the art should recognize
that, in general, the foregoing description and the accompanying
illustrations represent exemplary embodiments of the present invention
and should not be construed as limiting it. Indeed, the present
invention is limited only by the following claims and the reasonable
equivalents thereof. |