Information
-
Patent Grant
-
6758078
-
Patent Number
6,758,078
-
Date Filed
Wednesday, June 20, 200122 years ago
-
Date Issued
Tuesday, July 6, 200419 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Boyle, Fredrickson, Newholm, Stein & Grate, S.C.
-
CPC
-
US Classifications
Field of Search
US
- 072 134
- 072 138
- 140 31 A
-
International Classifications
-
Abstract
A spring coil assembly having a first row of coils arranged in a first spacing pattern and a second row of coils adjacent the first row and arranged in a second spacing pattern that is different from the first spacing pattern. The spring coil assembly can be assembled using an apparatus comprising a main conveyor adapted to convey a plurality of coils along an axis, an assembler which is operable to intertwine a plurality of coils into a spring coil assembly, and a transfer station operable to move a plurality of coils from the main conveyor into the assembler. The transfer station includes a plurality of pusher arms each of which include a gripper which is operable to grasp an individual coil, a carriage supporting the gripper arms and means for shifting the carriage axially relative to the axis so that a plurality of coils carried by the gripper arms are displaced in the direction of travel of the conveyor.
Description
FIELD OF THE INVENTION
The invention relates to spring coil assemblies, and more particularly to systems for making spring coil assemblies.
BACKGROUND OF THE INVENTION
Spring coil assemblies are well known for use in mattresses, furniture, cushions and the like. In the case of mattresses, it is known to use two types of coils in constructing the spring coil assembly. The industry commonly designates these two types of coils as right-hand coils and left-hand coils based on the location and orientation of the end wind of the coil. As used herein and in the appended claims, the terms “right-hand coils” and “left-hand coils” are used only by way of example, and different terminology could be substituted.
FIG. 1
shows a typical prior art coil assembly
10
. The prior art coil assembly includes a plurality of substantially identical adjacent rows R
1
, R
2
, R
3
. . . Each row R consists of alternating right-hand (designated both in FIG.
1
and in the other drawings as RH) and left-hand (designated as LH) coils. The plurality of adjacent rows forms a plurality of adjacent columns C
1
, C
2
, C
3
. . . . Each column C consists entirely of all right-hand coils or all left-hand coils. To remain competitive, manufacturers mass produce the spring coil assemblies, and are therefore limited to coil configurations obtainable with automated assembly machines. Consequently, known spring coil assemblies comprised of left-hand and right-hand coils have been configured substantially as shown in FIG.
1
.
To vary the overall firmness of the assembly, it is known to utilize coils made from different gauges of wire, thereby varying the spring characteristics and making the coil assembly softer or firmer. Again, due to the limitations of mass production, all of the right-hand coils are made from the same gauge of wire and all of the left-hand coils are made from the same gauge of wire. While the gauge of wire used for the left-hand coils may be different from the gauge of wire used for the right-hand coils, there are at most only two gauges of wire used in any one spring coil assembly. Since the configuration of coils maintains substantially the same pattern seen in
FIG. 1
, varying the wire gauge only allows for substantially homogenous variation of the firmness over the entire assembly.
In order to vary the firmness in different areas of the assembly, it is necessary to vary the spacing between the coils in each row. Due to the automated equipment used for mass production, this varied spacing is consistent throughout the rows of the spring coil assembly. This means that softer areas and firmer areas will run across the entire spring assembly in bands, i.e., along columns of coils.
SUMMARY OF THE INVENTION
The present invention provides a mattress or spring coil assembly construction having variation along the rows of the spring assembly to suit the needs of the consumer. The arrangement of coils is flexible, however, in that variations or permutations of the coil arrangement can be achieved within the scope of the present invention to provide multiple embodiments of the spring coil assembly. The multiple embodiments provide various characteristics and can be used to change the firmness of mass-produced coil assemblies in predetermined locations or zones as well as over the entire assembly. Advantageously, this coil assembly customization moves beyond simple selection of the firmness of the entire spring coil assembly or selected bands, and now allows the consumer to specify zones of the assembly where softer or firmer support is desired. The zones need not run across the entire assembly and therefore allow softer areas to be completely surrounded by firmer areas or vice-versa.
The present invention also provides an apparatus for making and assembling the multiple spring coil assembly embodiments. In one embodiment, the apparatus comprises a main conveyor adapted to convey a plurality of coils along an axis, an assembler which is operable to intertwine a plurality of coils into a spring coil assembly, and a transfer station operable to move a plurality of coils from the main conveyor into the assembler. The transfer station includes a plurality of pusher arms, each of which have a gripper that is operable to grasp an individual coil. The transfer station also includes a carriage supporting the gripper arms and a device for shifting the carriage in a direction substantially parallel to the axis so that the plurality of coils carried by the gripper arms are displaced in the direction of travel of the conveyor.
In another embodiment, the apparatus includes a coil forming machine having a wire feed advancing mechanism and being capable of forming coils in response to the advancement of wire by the wire feed advancing mechanism. The apparatus also includes a programmable control system capable of selectively varying the advancement of wire by the wire feed advancing mechanism between a consistent advancement, wherein coils are formed and placed on a main conveyor in predetermined consistent intervals, and an inconsistent advancement, wherein coils are formed and placed on the main conveyor in predetermined inconsistent intervals. In one aspect of the invention, the apparatus also includes a sensor element capable of producing a signal that can be selectively interpreted by the control system to stop the manufacturing of the spring coil assembly when the spacing of the coils on the main conveyor is inconsistent, or to permit the manufacturing of the spring coil assembly when the spacing of the coils on the main conveyor is inconsistent.
The present invention further provides a method of arranging coils in a spring coil assembly. The method includes arranging a first plurality of right-hand coils in spaced apart relation in a first row, arranging a first plurality of left-hand coils in spaced apart relation in the first row such that each of the first plurality of left-hand coils in the first row is located between a respective pair of right-hand coils in the first row, arranging a second plurality of right-hand coils in spaced apart relation in a second row, arranging a second plurality of left-hand coils in spaced apart relation in the second row such that each of the second plurality of left-hand coils in the second row is located between a respective pair of right-hand coils in the second row, and arranging the first and second rows such that the first plurality of right-hand coils in the first row is out of phase with the second plurality of right-hand coils in the second row.
In another embodiment, the method includes providing a coil forming machine having a wire feed advancing mechanism and that is capable of forming coils in response to the advancement of wire by the wire feed advancing mechanism. The method further includes selectively varying the advancement of wire by the wire feed advancing mechanism between a consistent advancement, wherein coils are formed and placed on a main conveyor in predetermined consistent intervals, and an inconsistent advancement, wherein coils are formed and placed on the main conveyor in predetermined inconsistent intervals. In one aspect of the invention, the method also includes selectively disregarding or disabling a sensor element that produces a signal intended to stop the manufacturing of the spring coil assembly when the coils on the main conveyor are spaced at inconsistent intervals.
Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims, and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a schematic top view of a prior art spring coil assembly.
FIG. 2
is a schematic top view of a first spring coil assembly embodying the invention.
FIG. 3
is a schematic top view of a second spring coil assembly which is an alternative embodiment of the invention.
FIG. 4
is a schematic top view of a third spring coil assembly which is an alternative embodiment of the invention.
FIG. 5
is a schematic top view of a fourth spring coil assembly which is an alternative embodiment of the invention.
FIG. 6
is a schematic top view of an apparatus embodying the invention, which can be used to assemble the spring coil assemblies illustrated in
FIGS. 2-5
.
FIG. 7
is a partial left side view of the apparatus of FIG.
6
.
FIG. 8
is a partial top view of the apparatus of FIG.
6
.
FIG. 9
is an enlarged top view showing a portion of the transfer apparatus shown in FIG.
8
.
FIG. 10
is an enlarged front view showing the portion of the transfer station shown in FIG.
9
.
FIG. 11
is a section view taken along line
11
—
11
in FIG.
10
.
Before one embodiment of the invention is explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 2
illustrates a spring coil assembly
20
which this disclosure may sometimes identify as “the standard posturized unit.” The assembly
20
includes multiple rows R and multiple columns C of right-hand and left-hand coils. The right-hand coils can be made from a different gauge of wire than the left-hand coils, but this is not a requirement of the invention. Furthermore, the right-hand and left-hand coils have a substantially identical widths W and depths D.
A first row R
1
includes a plurality of alternating right-hand and left-hand coils arranged in a first spacing pattern. Adjacent pairs of coils in the first row R
1
are uniformly spaced at a first distance d
1
. A second row R
2
adjacent the first row R
1
includes a plurality of right-hand and left-hand coils arranged in a second spacing pattern that is different from the first spacing pattern of the first row R
1
. At least one adjacent pair of coils in the second row R
2
is spaced at a second distance d
2
that is different from the first distance d
1
. The different spacing pattern in the second row R
2
is achieved by using at least one less coil in the second row R
2
than is used in the first row R
1
.
As seen in
FIG. 2
, the second row R
2
preferably has fewer right-hand coils than left-hand coils. This is achieved by eliminating at least one, and preferably more, of the right-hand coils from the normally alternating pattern used in the first row R
1
. Eliminating the right-hand coils in this manner provides gaps G
2
that are substantially equal in size to the width W of a right-hand coil. The gaps G
2
cause a change in characteristics of the spring coil assembly
10
between the first and second rows R
1
and R
2
. More specifically, the gaps G
2
make the assembly
20
softer or less firm in the second row R
2
than in the first row R
1
.
The spring coil assembly
20
further includes a third row R
3
adjacent the second row R
2
. The third row R
3
includes a plurality of right-hand and left-hand coils arranged in a third spacing pattern that is different from the first spacing pattern of the first row R
1
and can be different from the second spacing pattern of the second row R
2
. At least one pair of adjacent coils in the third row R
3
is spaced at a third distance d
3
that is the same as the second distance d
2
. The third row R
3
preferably has fewer left-hand coils than right-hand coils. This is achieved by eliminating at least one, and preferably more, of the left-hand coils from the normally alternating pattern used in the first row R
1
. Eliminating the left-hand coils in this manner provides gaps G
3
that are substantially equal in size to the width W of a left-hand coil. As seen in
FIG. 2
, the third row gaps G
3
alternate out of phase with the second row gaps G
2
. As used herein and in the appended claims to describe the spatial relationship of coils and/or gaps in adjacent rows, the term “out of phase” means offset substantially by the distance of one coil width W in either direction along the row.
The coil assembly
20
also includes a fourth row R
4
that is substantially identical to the second row R
2
and is adjacent the third row R
3
. The fourth row R
4
includes gaps G
4
that alternate out of phase with the third row gaps G
3
. A fifth row R
5
is substantially identical to the first row R
1
and is adjacent the fourth row R
4
. The fourth row R
4
is softer or less firm than the fifth row R
5
due to the presence of gaps G
4
.
The arrangement of the rows R
1
, R
2
, R
3
, R
4
and R
5
illustrates how the spring coil assembly
20
can be customized to have firmer zones and softer zones that do not extend across the entire assembly
20
in the direction of the columns C. The softer arrangement of rows R
1
to R
5
can be located in areas of a mattress requiring less support, such as the areas under a person's head or feet.
The coil assembly
20
also includes sixth, seventh and eighth rows R
6
, R
7
and R
8
that are substantially identical to the first row R
1
. The arrangement of rows R
6
to R
8
provides a firmer area of the assembly
10
and can be located in areas of a mattress requiring more support, such as the areas under a person's torso or midsection.
The coil assembly
20
also includes ninth, tenth, eleventh, twelfth and thirteenth rows R
9
, R
10
, R
11
, R
12
and R
13
that are substantially identical to the rows R
1
, R
2
, R
3
, R
4
and R
5
, respectively. Like the arrangement of rows R
1
to R
5
, the arrangement of the rows R
9
to R
13
can be located in areas of a mattress requiring less support, such as the areas under a person's head or feet. Finally, the coil assembly
20
includes end rows R
0
and R
14
that are substantially identical to the first row R
1
. The end rows R
0
and R
14
provide firm support around their respective portions of the perimeter of the coil assembly
20
.
The arrangement of the rows R of the coil assembly
20
drives the arrangement of the columns C. It is worth noting that the coil assembly
20
includes columns C that consist entirely of either of all left-hand coils or all right-hand coils. The gaps G in the rows also create gaps in the columns C. The gaps in any two adjacent columns are out of phase with one another, just as is the case with adjacent rows. As used herein and in the appended claims to describe the spatial relationship of coils and/or gaps in adjacent columns, the term “out of phase” means offset substantially by the distance of one coil depth D in either direction along the column.
It is important to note that the coil assembly
20
is not limited to the configuration shown in FIG.
2
. For example, the coil assembly
20
could be practiced with two or more end rows at each end of the assembly
20
. Alternatively, the assembly
20
need not have any end rows at all. In addition, it should be noted that the length of the individual rows can vary to fit the dimensional requirements of the coil assembly
20
.
Furthermore, it is important to note that the relative arrangement of coils illustrated between rows R
1
and R
5
could include fewer or more rows like rows R
2
, R
3
and R
4
. The alternating sequence of rows R
2
and R
3
could also be transposed to change the arrangement of gaps G
2
and G
3
. If this were the case, it would also be desirable, but not necessary, to transpose any additional rows (e.g. R
4
) to continue the proper out of phase, alternating gap sequence. Likewise, the arrangement illustrated between rows R
6
and R
8
can include fewer or more rows like R
7
.
FIG. 3
illustrates a spring coil assembly
30
that is a second embodiment of the present invention which this disclosure may sometimes identify as the “X unit.” The assembly
30
includes multiple rows R and multiple columns C of right-hand and left-hand coils. The right-hand coils can be made from a different gauge of wire than the left-hand coils, but this is not a requirement of the invention. Furthermore, the right-hand and left-hand coils have a substantially identical widths W and depths D.
The rows R consist of alternating left-hand and right-hand coils. As seen in
FIG. 3
, a first row R
1
is adjacent a second row R
2
and the plurality of right-hand coils in the first row R
1
alternates out of phase with the plurality of right-hand coils in the second row R
2
. Likewise, the plurality of left-hand coils in the first row R
1
alternates out of phase with the plurality of left-hand coils in the second row R
2
. Due to the alternating coil configuration in the rows, the assembly
30
also has an alternating arrangement of right-hand and left-hand coils in the columns C. Unlike the prior art coil assembly
10
of
FIG. 1
, the coil assembly
30
of
FIG. 3
has this alternating arrangement of left-hand and right-hand coils in both the rows R and the columns C, and therefore provides a more homogenous coil arrangement that is advantageous in terms of comfort and support.
FIG. 4
illustrates a spring coil assembly
40
that is a third embodiment of the present invention which this disclosure may sometimes identify as the “zoned unit.” The assembly
40
again includes multiple rows R and multiple columns C of right-hand and left-hand coils. The right-hand coils can be made from a different gauge of wire than the left-hand coils, but this is not a requirement of the invention. Furthermore, the right-hand and left-hand coils have a substantially identical widths W and depths D.
Again, the rows R consist of alternating left-hand and right-hand coils. As seen in
FIG. 4
, the first four rows R
1
to R
4
and the last four rows R
10
to R
13
are arranged like the rows in the prior art assembly
10
. The fifth through ninth rows R
5
to R
9
are arranged in the manner described above with respect to the “X unit” coil assembly
30
of FIG.
3
. In other words, the plurality of right-hand coils in row R
4
alternates out of phase with the plurality of right-hand coils in row R
5
, which in turn, alternates out of phase with the plurality of right-hand coils in row R
6
. Consequently, the plurality of left-hand coils in row R
4
alternates out of phase with the plurality of left-hand coils in row R
5
, which in turn, alternates out of phase with the plurality of left-hand coils in row R
6
. This arrangement continues through row R
10
to form a zone in the assembly
40
that has the more homogenous coil arrangement described above with respect to assembly
30
.
It should be noted that the assembly
40
is not limited to the particular configuration of rows shown in
FIG. 4
, but can include zones having different numbers of rows as well as multiple zones within the assembly
40
. The coil assembly
30
is also assembled using the apparatus
60
described below.
FIG. 5
illustrates a fourth embodiment of a spring coil assembly
50
of the present invention which this disclosure may sometimes identify as “the X posturized unit.” The assembly
50
includes multiple rows R and multiple columns C of right-hand and left-hand coils. The right-hand coils can be made from a different gauge of wire than the left-hand coils, but this is not a requirement of the invention. Furthermore, the right-hand and left-hand coils have a substantially identical widths W and depths D.
The coil assembly
50
combines the standard posturized arrangement of the coil assembly
20
shown in
FIG. 2
, with the out of phase alternating coil arrangement of the X unit coil assembly
30
shown in FIG.
3
. More specifically, a first row R
1
includes a plurality of alternating right-hand and left-hand coils arranged in a first spacing pattern. Adjacent pairs of coils in the first row R
1
are uniformly spaced at a first distance d
1
. A second row R
2
adjacent the first row R
1
includes a plurality of right-hand and left-hand coils arranged in a second spacing pattern that is different from the first spacing pattern of the first row R
1
. At least one adjacent pair of coils in the second row R
2
is spaced at a second distance d
2
that is different from the first distance d
1
. The different spacing pattern in the second row R
2
is achieved by using at least one less coil in the second row R
2
than is used in the first row R
1
. Furthermore, the plurality of right-hand coils in the first row R
1
alternates out of phase with the plurality of right-hand coils in the second row R
2
.
As seen in
FIG. 5
, the second row R
2
preferably has fewer left-hand coils than right-hand coils. This is achieved by eliminating at least one, and preferably more, of the left-hand coils from the normally alternating pattern used in the first row R
1
. Eliminating the left-hand coils in this manner provides gaps G
2
that are substantially equal in size to the width W of a left-hand coil. The gaps G
2
cause a change in characteristics of the spring coil assembly
50
between the first and second rows R
1
and R
2
. More specifically, the gaps G
2
make the assembly
50
softer or less firm in the second row R
2
than in the first row R
1
.
The spring coil assembly
50
further includes a third row R
3
adjacent the second row R
2
. The third row R
3
includes a plurality of right-hand and left-hand coils arranged in a third spacing pattern that is different from the first spacing pattern of the first row R
1
and can be different from the second spacing pattern of the second row R
2
. At least one pair of adjacent coils in the third row R
3
is spaced at a third distance d
3
that is the same as the second distance d
2
. The third row R
3
preferably has fewer left-hand coils than right-hand coils. This is achieved by eliminating at least one, and preferably more, of the left-hand coils from the normally alternating pattern used in the first row R
1
. Eliminating the left-hand coils in this manner provides gaps G
3
that are substantially equal in size to the width W of a left-hand coil. As seen in
FIG. 5
, the third row gaps G
3
alternate out of phase with the second row gaps G
2
. Additionally, the plurality of right-hand coils in the second row R
2
alternate out of phase with the plurality of right-hand coils in the third row R
3
.
The coil assembly
50
also includes a fourth row R
4
that is substantially identical to the second row R
2
and is adjacent the third row R
3
. The fourth row R
4
includes gaps G
4
that alternate out of phase with the third row gaps G
3
. A fifth row R
5
is substantially identical to the first row R
1
and is adjacent the fourth row R
4
. The fourth row R
4
is softer or less firm than the fifth row R
5
due to the presence of gaps G
4
.
The arrangement of the rows R
1
, R
2
, R
3
, R
4
and R
5
illustrates how the spring coil assembly
50
can be customized to have firmer zones and softer zones that do not extend across the entire assembly
50
in the direction of the columns C. The softer arrangement of rows R
1
to R
5
can be located in areas of a mattress requiring less support, such as the areas under a person's head or feet.
The coil assembly
50
also includes sixth, seventh and eighth rows R
6
, R
7
and R
8
that are arranged like the rows of coil assembly
30
. The arrangement of rows R
6
to R
8
provides a homogenous and firmer area of the assembly
50
and can be located in areas of a mattress requiring more support, such as the areas under a person's torso or mid-section.
The coil assembly
50
also includes ninth, tenth, eleventh, twelfth and thirteenth rows R
9
, R
10
, R
11
, R
12
and R
13
that are substantially identical to the rows R
1
, R
2
, R
3
, R
4
and R
5
, respectively. Like the arrangement of rows R
1
to R
5
, the arrangement of the rows R
9
to R
13
can be located in areas of a mattress requiring less support, such as the areas under a person's head or feet. Finally, the coil assembly
50
includes an end row R
0
in out of phase relation to row R
1
and an end row R
14
in out of phase relation row R
13
. The end rows R
0
and R
14
provide firm support around their respective portions of the perimeter of the coil assembly
50
.
The arrangement of the rows R of the coil assembly
50
drives the arrangement of the columns C. The gaps G in the rows also create gaps in the columns C. The gaps in any two adjacent columns are out of phase with one another, just as is the case with adjacent rows. It is worth noting that the coil assembly
50
includes columns C that consist both of alternating and consecutive left-hand coils or right-hand coils. In locations in a column where no gap exists between two consecutive rows, the adjacent coils of the column alternate between left-hand and right-hand coils. In locations in a column where a gap does exist between two consecutive rows, the adjacent coils of the column will be of the same hand (right-handed as shown in FIG.
5
).
It is important to note that the coil assembly
50
is not limited to the configuration shown in FIG.
5
. For example, the coil assembly
50
could be practiced with two or more end rows at each end of the assembly
50
. Alternatively, the assembly
50
need not have any end rows at all. In addition, it should be noted that the length of the individual rows can vary to fit the dimensional requirements of the coil assembly
50
.
Furthermore, it is important to note that the relative arrangement of coils illustrated between rows R
1
and R
5
could include fewer or more rows like rows R
2
, R
3
and R
4
. The alternating sequence of rows R
2
and R
3
could also be transposed to change the arrangement of gaps G
2
and G
3
. If this were the case, it would also be desirable, but not necessary, to transpose any additional rows (e.g. R
4
) to continue the proper out of phase, alternating gap sequence. Likewise, the arrangement illustrated over rows R
6
to R
8
can include fewer or more rows.
All of the previously-described spring coil assemblies
10
,
20
,
30
,
40
, and
50
can be made using a coil spring forming and assembly apparatus
60
, as shown in
FIGS. 6-11
. The general construction and operation of the apparatus
60
is described in U.S. Pat. No. 5,950,473, which is commonly assigned to the assignee of this application and is hereby incorporated by reference. Referring to
FIG. 6
, the coil spring forming and assembling apparatus
60
includes first and second coil forming machines
64
and
68
, respectively, which form and deliver coil springs to a single, incrementally advancing main conveyor
72
. The main conveyor
72
delivers the coil springs to a coil spring transfer apparatus
76
which, in turn, delivers the coil springs to a coil spring assembly apparatus
80
. The coil spring assembly apparatus
80
assembles the coil springs into the various coil spring assemblies
10
,
20
,
30
,
40
, and
50
described above.
The coil spring forming and assembling apparatus
60
also includes a control system
84
, according to which, operation of the coil spring forming machines
64
and
68
are dependent on completion of the incremental advancement of the main conveyor
72
, and operation of the main conveyor
72
is dependent on completion and delivery of a fully completed coil spring by one or both of the coil spring forming machines
64
and
68
. As will be described below, the control system
84
used with the present invention can be programmed to operate the coil spring forming machines
64
and
68
and the main conveyor
72
even if a coil is missing on the main conveyor
72
, as is the case when a gap is required in the coil spring assembly. The control system
84
can also distinguish between an expected missing coil (i.e., a coil left out intentionally to provide a gap) and an unexpected missing coil (i.e., a coil that accidentally fell off the main conveyor
72
), in order to determine whether the coil forming and assembling apparatus
60
should be shut down or whether it should continue to run. In prior art coil forming and assembly machines on the other hand, the absence of a coil would typically stop the spring forming machines and the main conveyor so that the missing coil could be replaced.
FIG. 7
shows the coil forming machines
64
and
68
in greater detail. The coil forming machines
64
and
68
are substantially mirror images of one another, with one of the coil forming machines
64
and
68
forming left-hand coils and the other of the coil forming machines
64
and
68
forming right-hand coils. Coil forming machines of this type are well-known and will not be described in detail. The coil forming machine
64
is driven by a main driving device
86
and the coil forming machine
68
is driven by a main driving device
88
. The coil forming machine
64
includes a wire feed advancing mechanism
92
that is driven by wire-feed driving device
96
, which is operative and energized in response to operation of the main driving device
86
. Likewise, the coil forming machine
68
includes a wire feed advancing mechanism
100
that is driven by wire-feed driving device
104
, which is operative and energized in response to operation of the main driving device
88
. The construction of the wire feed advancing mechanisms
92
and
100
is also well-known.
Wire is fed by the wire feed advancing mechanisms
92
and
100
to respective coil spring forming heads
108
and
112
that operate to form each individual coil. The wire feed driving devices
96
and
104
are energized in response to signals from the control system
84
. When the driving devices
96
and
104
receive the signals, the wire feed advancing mechanisms
92
and
100
feed the wire to the forming heads
108
and
112
in order to form the coils. Previously, these signals were sent at consistent intervals, and therefore, coils were formed at consistent intervals.
To create the desired spacing gaps in the spring coil assemblies
20
and
50
, the control system programming can be altered to send energization signals to the wire feed driving devices
96
and
104
at predetermined inconsistent intervals. In other words, the previously consistent pattern of energization signals may now be made inconsistent by eliminating one or more energization signals. If the drive devices
96
and
104
do not receive an energization signal, no wire will be advanced by the respective wire feed advancing mechanisms
92
and
100
and no coil will be formed.
Meanwhile, the rest of the coil forming, conveying, and assembling operations continue to index as if a coil were actually formed in the usual consistent manner. Therefore the gap created by the missing coil is never filled, but rather persists throughout the indexing. The transferring of coils to the main conveyor
72
continues in the usual manner. As a result, the spacing of the coils on the main conveyor
72
, which ultimately corresponds substantially to the spacing of the coils in the various rows of the spring coil assemblies
20
and
50
, is inconsistent due to the gaps created by the missing coils. Using this technique, spacing gaps can be created by selectively controlling the wire feed advancing mechanisms
92
and
100
on the left-hand and/or the right-hand coil forming machines
64
and
68
, as desired.
Of course, gaps can also be created in other ways, such as by manually or automatically removing selected coils after they have been formed. However, selectively controlling the wire feed as described above creates gaps without generating extra coils that must be discarded. This reduces the cost of manufacturing spring coil assemblies.
As the gap created by the missing coil advances through the various forming, conveying, and assembling stations, it may be necessary to disable or disregard any sensing devices normally used to detect missing coils. As seen in
FIG. 7
, the apparatus
60
includes a sensor
116
positioned above the main conveyor
72
. The sensor
116
is coupled to the control system
84
and detects when a coil is missing from the main conveyor
72
. Any suitable sensor, including optical sensors, limit switches, proximity sensors and the like, can be used. Additionally, the sensor
116
can be located at other places on the apparatus
60
.
As mentioned above, for making spring coil assemblies that have gaps, the control system
84
is programmed to know when to expect a missing coil so that the coil forming and assembling apparatus
60
continues to operate. However, if the sensor
116
detects an unexpected missing coil, the coil forming and assembling apparatus
60
can still be shut down. For example, in the situation where gaps are desired and the coils are intentionally missing, the control system programming is altered to anticipate missing coils in certain intervals or incremental positions. If the signal from the sensor
116
indicates that a coil is missing, and that signal is expected, the operation would not be shut down, but rather would continue as normal. Yet, if an unexpected missing coil signal from the sensor
116
is received, the operation can still be shut down.
From the coil forming machines
64
and
68
, the coils are transferred to respective infeed conveyors
120
and
124
. The infeed conveyors
120
and
124
carry the coils to the main conveyor
72
which travels along an axis
128
. The coils are transferred to the main conveyor
72
such that the coils on the main conveyor
72
are arranged in a uniformly spaced-apart alternating sequence of right-hand and left-hand coils. The infeed conveyors are described in detail in pending U.S. Pat. application Ser. No. 09/753,936, which is hereby incorporated by reference.
Referring to
FIG. 8
, the infeed conveyors
120
and
124
continue to supply coils to the main conveyor
72
. The main conveyor
72
carries the coils to a position adjacent the assembly apparatus
80
, which is operable to intertwine a row R of coils into a spring coil assembly. Associated with the assembly apparatus
80
is the transfer apparatus
76
, which is operable to move a row R of coils from the main conveyor
72
into the assembly apparatus
80
. In general, the transfer apparatus
76
and the assembly apparatus
80
are located on opposite sides of the main conveyor
72
, with the assembly apparatus
80
being vertically offset upwardly from the main conveyor
72
. The main conveyor
72
advances a first row R of coils to the transfer apparatus
76
in a direction of motion along the axis
128
into a loading position adjacent the transfer apparatus
76
and the assembly apparatus
80
. The transfer apparatus
76
removes the first row R of coils from the main conveyor
72
and places the coils into the assembly apparatus
80
. During the transfer of the first row R of coils from the main conveyor
72
to the assembly apparatus
80
, the main conveyor
72
advances a second row R of coils into the loading position.
Various configurations and arrangements can be successfully used for the transfer apparatus
76
. In the illustrated embodiment, the transfer apparatus
76
includes a plurality of pusher arms
132
, each of which includes a gripper
136
which is operable to grasp an individual coil. In the illustrated embodiment, the first pusher arm
132
(shown as the right-most pusher arm in
FIGS. 8 and 9
) can be rotated by an actuator
138
to rotate the end coil for assembly, as is known by those skilled in the art. The pusher arms
132
are coupled to a pusher carriage
140
, which is supported by a frame
144
in a manner discussed below, so as to afford movement of the pusher arms
132
in several degrees of freedom. Gripper actuators
146
are mounted on the pusher carriage
140
and operate to open and close the grippers
136
in a known manner.
The frame
144
includes opposing vertical members
148
, which are substantially mirror images of one another. Each vertical frame member
148
includes a pair of spaced-apart vertical guide rails
152
(only one is shown at each end of the frame
144
) that guides the vertical movement of the pusher carriage
140
relative to the frame
144
.
The pusher carriage
140
includes a substantially horizontal pusher member
156
that supports the pusher arms
132
. The horizontal pusher member
156
is supported between opposing vertical support assemblies
160
(only one is shown in FIG.
10
). The support assemblies
160
are substantially mirror images of one another and only one will be described in detail. Each support assembly
160
includes a substantially vertical base plate
164
that supports a pair of upper rollers
168
and a pair of lower rollers
172
(only one roller of each pair is shown). The upper and lower rollers
168
and
172
engage the respective vertical guide rails
152
to guide the movement of the pusher carriage
140
in the vertical direction. Of course, other guiding arrangements, such as rack and pinion arrangements, bar and slider arrangements, and the like, could also be used.
A vertical actuator
176
is coupled between the base plate
164
and the frame support
148
to cause the vertical movement of the base plate
164
and the entire pusher carriage
140
. In the illustrated embodiment, the vertical actuator
176
is a piston/cylinder actuator having a cylinder
177
fixed to the frame support
148
and a piston rod
178
fixed to the base plate
164
via a connection member
179
. Of course, other mounting configurations and actuators could be used.
Also mounted to the base plate
164
is an L-shaped support member
180
(see FIGS.
10
and
11
). An arm of the support member
180
extends from the base plate
164
and supports a guide assembly
184
(see FIG.
10
). The guide assembly
184
operates to guide the movement of the horizontal pusher member
156
in a longitudinal direction and in a lateral direction. For purposes of this description, the term “longitudinal direction” refers to a direction substantially parallel to the axis
128
and the direction of travel of the main conveyor
72
, while the term “lateral direction” refers to a direction substantially perpendicular to the axis
128
and the direction of travel of the main conveyor
72
.
As best seen in
FIG. 11
, the guide assembly
184
includes an L-shaped member
188
supported on the support member
180
. A lateral actuator assembly
192
is mounted to the L-shaped member
188
for moving the pusher carriage
140
in the lateral direction. In the illustrated embodiment, the lateral actuator assembly
192
includes a rod-less air cylinder
196
that extends in the lateral direction. Rod-less air cylinders are known to those skilled in the art, and in the illustrated embodiment, the cylinder
196
includes a piston member
200
that protrudes from a slot (not shown) formed in the top of the cylinder
196
. The slot extends in the lateral direction and is kept closed by a stainless steel band (not shown) that moves with the piston member
200
as the piston member
200
moves laterally. The piston member
200
is coupled to a guide plate
204
that moves laterally along a guide rail
208
as the piston member
200
moves in the cylinder
196
. It should be noted that other types of actuators and actuator configurations can be substituted for the illustrated lateral actuator assembly
192
.
The guide assembly
184
also includes a spacer plate
212
fixed to the guide plate
204
for movement therewith. More than one spacer plate
212
can be included to obtain the necessary vertical spacing from the guide plate
204
. Mounted on the spacer plate
212
is a slide plate
216
, which is made from a low-friction, wear-resistant material, preferably a plastic. The purpose of the slide plate
216
will be described below.
The guide assembly
184
further includes a U-shaped collar
220
mounted on the slide plate
216
. The U-shaped collar
220
includes opposing vertical members
224
and a top member
228
. The top member
228
includes an aperture
232
(see
FIGS. 8 and 9
) sized to receive a pin
236
. A rigid strip
240
preferably covers the aperture
232
so that the pin
236
can not move upwardly out of the aperture
232
. The purpose of the pin
236
will be described below.
A stop member
244
is mounted to one of the opposing vertical members
224
and cooperates with a sensor (not shown) to control the extent of lateral movement of the pusher carriage
140
toward the main conveyor
72
. To control the extent of lateral movement away from the main conveyor
72
, a sensor
245
cooperates with the top member
228
of the U-shaped collar
220
. As best seen in
FIG. 11
, the sensor
245
is mounted on an L-shaped member
246
, which is coupled to the L-shaped member
188
.
As seen in
FIGS. 8-11
, the pusher member
156
includes opposing end portions
248
which are slidably received in the respective U-shaped collars
220
. Each end portion
248
is sized to be slidably retained for movement in the longitudinal direction between the opposing vertical members
224
. The end portion
248
is supported on its bottom side by the slide plate
216
, which provides a reduced-friction, wear-resistant surface for facilitating the sliding of the end portion
248
. In the illustrated embodiment, the end portions
248
are separate members that are coupled to the pusher member
156
, however, the end portions
248
could alternatively be integral with the pusher member
156
.
Each end portion
248
includes a slot
252
that receives the pin
236
. The slot
252
and the pin
236
cooperate to limit the respective sliding movement between the end portion
248
and the U-shaped collars
220
to the longitudinal direction. The range of longitudinal sliding motion is limited by the length of the slot in the longitudinal direction. In the illustrated embodiment, the slot
252
is configured so that the end portions
248
, and therefore the pusher member
156
and the gripper arms
132
, can shift longitudinally one coil position (to the left or to the right as shown in FIGS.
8
and
9
).
The longitudinal shifting of the pusher member
156
is actuated by a longitudinal actuator
256
. In the illustrated embodiment, the longitudinal actuator
256
is a piston/cylinder actuator having a cylinder
260
, a piston (not shown) inside the cylinder
260
, and a rod
264
coupled to the piston and extending from the cylinder
260
. The rod
264
is coupled to the pusher member
156
at a mounting member
268
. The cylinder
260
is fixed to the U-shaped collar
220
via an L-shaped member
272
. Therefore, when the actuator
256
is activated (either, pneumatically, hydraulically, or otherwise), the rod
264
extends or retracts with respect to the cylinder
260
and the U-shaped collar
220
to move the pusher member
156
longitudinally. Of course, other mounting configurations and actuators could be used.
FIGS. 9 and 10
illustrate the pusher member
156
in one extreme longitudinal position. As seen in
FIGS. 9 and 10
, the pin
236
abuts the left-most side of the slot
252
, meaning that the pusher member
156
is moved as far to the right as possible. This position will be called the “home” position for purposes of the discussion below.
FIG. 8
illustrates the pusher member
156
in the other extreme longitudinal position. As seen in
FIG. 8
, the pins
236
abut the right-most side of the respective slots
252
, meaning that the pusher member
156
is moved as far to the left as possible. This position will be called the “shifted” position for purposes of the discussion below. Notice that the rod
264
of the longitudinal actuator
256
is extended further in
FIG. 8
than in
FIGS. 9 and 10
.
Operation of the transfer apparatus
76
will now be described. For the purpose of discussion only, it is assumed that the coils are placed on the main conveyor
72
so that a complete row R begins with a right-hand coil in a first position P
1
and ends with a right-hand coil in a last position P
17
(see FIGS.
8
and
9
). Because the coils are placed on the main conveyor
72
in pairs, a position P
18
also exists, but is not used for a complete row R. If desired, a gap can exist at the position P
18
because that coil would not be used for the complete row R. Between the positions P
1
and P
18
, the coils alternate between left-hand coils and right-hand coils, such that left-hand coils will be in positions P
2
and P
18
. As described above, the alternating row of coils may include gaps where coils are intentionally absent.
With the pusher member
156
in the home position (as shown in
FIG. 9
) a first row R of coils is advanced along the main conveyor
72
. The lateral actuator assemblies
192
are activated to move the pusher member
156
in the lateral direction toward the main conveyor
72
so the grippers
136
can grasp the coils. The gripper actuators
146
are activated, enabling the grippers
136
to grasp the coils. The right-most gripper
136
grasps the right-hand coil from the position P
1
and the left-most gripper
136
grasps the right-hand coil from the position P
17
. The actuator
138
is then activated to rotate the coil picked up from position P
1
to enable proper assembly in the assembly apparatus
80
. With the row R of coils held securely by the grippers
136
, the pusher carriage
140
moves so that the grippers
136
can place the row R of coils in the assembly apparatus
80
. The pusher carriage
140
is moved as needed by the vertical actuators
176
and the lateral actuator assemblies
192
until the row R of coils can be deposited in the assembly apparatus
80
, as shown in FIG.
8
. The pusher member
156
is then returned to the home position.
When making the spring coil assemblies
10
and
20
, in which each column C consists entirely of either left-hand coils or right-hand coils, the operation of the transfer apparatus
76
is simply repeated as described above. The transfer apparatus
76
transfers each row R into the assembly apparatus
80
so that the first and last columns C
1
and C
17
, respectively, will always consist of right-hand coils.
However, when making the spring coil assemblies
30
,
40
, and
50
, in which the columns C consist of alternating left-hand and right-hand coils, the transfer apparatus
76
employs the longitudinal actuator
256
to move the pusher member
156
to the shifted position. This permits shifting the relative position of coils in adjacent rows R so that the position of right-hand and left-hand coils in adjacent rows are out of phase. As seen in
FIG. 8
, when the pusher member
156
is moved to the shifted position, the right-most gripper
136
will grasp the left-hand coil in position P
2
and the left-most gripper
136
will grasp the left-hand coil in position P
18
. In
FIG. 8
, there is no coil on the main conveyor
72
at the position P
1
because the position P
1
is not being used for this shifted row R. The coil at position P
1
is intentionally left off of the main conveyor
72
, as described above.
With the shifted row R of coils held securely by the grippers
136
, the pusher carriage
140
moves so that the grippers
136
can place the shifted row R of coils in the assembly apparatus
80
. The pusher carriage
140
is moved as needed by the vertical actuators
176
, the lateral actuator assemblies
192
, and the longitudinal actuator
256
until the shifted row R of coils can be deposited in the assembly apparatus
80
, as shown in FIG.
8
. The pusher member
156
is then returned to the home position. By shifting the pusher member
156
longitudinally during every other cycle, the transfer apparatus
76
delivers consecutive, phase-shifted rows of coils to the assembly apparatus
80
, as required for forming the spring coil assemblies
30
,
40
, and
50
.
The actuators
146
,
176
,
192
and
256
are preferably actuated by means of a numeric control or other similar programmable controller (not shown). The specific sequence of motion caused by the actuators
176
,
192
, and
256
is not critical to the invention as long as the grippers
136
can grasp the rows of coils from the main conveyor
72
and deposit the rows into the assembly apparatus
80
as needed to create the desired spring coil assemblies.
Various features of the invention are set forth in the following claims.
Claims
- 1. An apparatus for assembling a spring coil assembly, comprising:a main conveyor adapted to convey a plurality of coils in a direction of travel along a longitudinal axis; an assembler which is operable to intertwine a plurality of rows of coils into a spring coil assembly; and a transfer station configured to simultaneously move a plurality of coils, defining a row of coils, from the main conveyor into the assembler, the transfer station including: a plurality of pusher arms, each pusher arm including a gripper which is operable to grasp an individual coil located on the main conveyor; a carriage supporting the pusher arms; and an actuator for shifting the carriage in a direction substantially parallel to the longitudinal axis so that the row of coils carried by the grippers is displaced in the direction of travel of the conveyor relative to an adjacent row of coils.
- 2. The apparatus of claim 1, wherein the assembler and the main conveyor are vertically offset from each other, and wherein the carriage is adapted for vertical movement so as to enable the pusher arms to grasp the coils at a first elevation and to move the coils into the assembler at a second elevation.
- 3. The apparatus of claim 1, wherein the carriage is mounted to a support structure for movement in the direction substantially parallel to the axis, and further comprising a stop arrangement interposed between the carriage and the support structure for controlling movement of the carriage.
- 4. The apparatus of claim 3, wherein the stop arrangement includes a slot defining a pair of spaced apart ends, wherein the slot extends in a direction substantially parallel to the axis, and a pin disposed within the slot, wherein engagement of the pin with the ends of the slot is operable to control the position of the carriage.
- 5. The apparatus of claim 4, wherein the slot is associated with the carriage and wherein the pin is associated with the support structure.
- 6. The apparatus of claim 3, wherein the plurality of coils are supplied by a coil forming machine having a wire feed advancing mechanism, wherein the coil forming machine is capable of forming coils in response to the advancement of wire by the wire feed advancing mechanism; and further comprising a programmable control system capable of selectively varying the advancement of wire by the wire feed advancing mechanism between a consistent advancement, wherein coils are formed and placed on the main conveyor in predetermined consistent intervals, and an inconsistent advancement, wherein coils are formed and placed on the main conveyor in predetermined inconsistent intervals.
- 7. The apparatus of claim 6, further comprising a sensor element capable of producing a signal that can be selectively interpreted by the control system to stop the spring coil assembly when the spacing of the coils on the main conveyor is inconsistent, or to permit operation of the spring coil assembly when the spacing of the coils on the main conveyor is inconsistent.
- 8. The apparatus of claim 1, wherein the carriage is supported on a longitudinal guide arrangement, and wherein the actuator is operable to shift the carriage in the longitudinal direction by moving the carriage on the longitudinal guide arrangement.
- 9. A method of assembling a spring coil assembly using the apparatus of claim 1, comprising the steps of supplying a first row of coils to the assembler, and subsequently supplying a second row of coils to the assembler after shifting the transfer station in the longitudinal direction subsequent to supplying the first row of coils to the assembler.
- 10. An apparatus for assembling a spring coil assembly, the apparatus comprising:an infeed conveyor adapted to convey a plurality of coils; a main conveyor adapted to receive coils from the infeed conveyor and to convey the coils along a longitudinal axis in a first generally horizontal direction; a main conveyor transfer station to transfer coils to the main conveyor from the infeed conveyor; an assembler which is operable to intertwine a plurality of rows of coils into a spring coil assembly; and a transfer station operable to sequentially move a plurality of coils in rows from the main conveyor into the assembler, the transfer station including a plurality of pusher arms, each of the pusher arms including a gripper which is operable to grasp an individual coil, a pusher member supporting the pusher arms; a carriage supporting the pusher member; vertical guides which support the carriage; a vertical actuator associated with the carriage for indexing the carriage along the vertical guides to provide selective vertical movement of the carriage relative to the main conveyor; lateral guides which support the carriage; a lateral actuator associated with the carriage for indexing the carriage along the lateral guides to provide selective lateral movement of the carriage relative to the main conveyor in a second generally horizontal direction perpendicular to the longitudinal axis of the main conveyor; a longitudinal guide assembly on the carriage and supporting the pusher member; and a longitudinal actuator for shifting the pusher member along the longitudinal guide assembly in a direction substantially parallel to the longitudinal axis so that the plurality of coils carried by the grippers is displaced in the longitudinal direction of travel of the main conveyor.
- 11. An apparatus for assembling a spring coil assembly, the apparatus comprising:a coil forming machine having a wire feed advancing mechanism and being configured to form coils in response to the advancement of wire by the wire feed advancing mechanism; a main conveyor adapted to receive coils from the coil forming machine and to convey the coils along an axis; and a programmable control system configured to selectively vary the advancement of wire by the wire feed advancing mechanism between a consistent advancement, wherein coils are formed and placed on the main conveyor in predetermined consistent intervals, and an inconsistent advancement, wherein coils are formed and placed on the main conveyor in predetermined inconsistent intervals.
- 12. The apparatus of claim 11, further comprising:a sensor element configured to produce a signal that can be selectively interpreted by the control system to stop the manufacturing of the spring coil assembly when the spacing of the coils on the main conveyor is inconsistent, or to permit the manufacturing of the spring coil assembly when the main conveyor is inconsistent.
- 13. The apparatus of claim 12, further comprising an assembler which is operable to intertwine a plurality of coils into a spring coil assembly, and a transfer station operable to move a plurality of coils from the main conveyor into the assembler.
- 14. The apparatus of claim 13, wherein the transfer station comprises:a plurality of pusher arms, wherein each pusher arm includes a gripper which is operable to grasp an individual coil; a carriage supporting the pusher arms; and an actuator for shifting the carriage in a direction along the axis so as to enable displacement of the coils carried by the gripper arms in the direction of travel of the conveyor.
- 15. The apparatus of claim 14, wherein the carriage is mounted to a support structure for movement in the direction along the axis, and wherein the actuator includes a stop arrangement interposed between the carriage and the support structure for controlling movement of the carriage in the direction along the axis.
US Referenced Citations (9)
Foreign Referenced Citations (3)
Number |
Date |
Country |
0899034 |
Mar 1999 |
EP |
793155 |
Jan 1936 |
FR |
1325945 |
May 1963 |
FR |