U.S. patent number 3,633,766 [Application Number 04/885,835] was granted by the patent office on 1972-01-11 for transfer mechanism.
This patent grant is currently assigned to Textron, Inc.. Invention is credited to Erwin B. Byam, Gregory L. Klein.
United States Patent |
3,633,766 |
Byam , et al. |
January 11, 1972 |
**Please see images for:
( Certificate of Correction ) ** |
TRANSFER MECHANISM
Abstract
A transfer mechanism capable of transferring and rotating
workpieces from one die station to another in a header or similar
apparatus, comprising first lever means pivotally mounted to the
frame of the machine and bracket means pivotally connected to the
first lever means. Sliding and rotating means having finger means
thereon, are mounted on the bracket means. Pivotal means act on
said sliding and rotating means to raise and lower the finger means
to open and closed positions, respectively. First and second drive
means are provided to reciprocate the bracket means and actuate the
pivotal means in timed relationship to the bracket means.
Inventors: |
Byam; Erwin B. (Wolcott,
CT), Klein; Gregory L. (Cheshire, CT) |
Assignee: |
Textron, Inc. (Providence,
RI)
|
Family
ID: |
25387794 |
Appl.
No.: |
04/885,835 |
Filed: |
December 17, 1969 |
Current U.S.
Class: |
414/626;
72/422 |
Current CPC
Class: |
B21K
27/04 (20130101) |
Current International
Class: |
B21K
27/00 (20060101); B21K 27/04 (20060101); B21d
043/10 () |
Field of
Search: |
;214/1BC,1BD,1Q
;72/422 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Forlenza; Gerald M.
Assistant Examiner: Abraham; George F.
Claims
What is claimed is:
1. A transfer mechanism capable of moving workpieces from one
station to another in a header or similar apparatus having a frame,
comprising
a. first lever means pivotally mounted to said frame,
b. bracket means pivotally mounted to said first lever means,
c. sliding and rotating means located on said bracket means and
having finger means thereon,
d. pivotal means for raising and lowering said sliding and rotating
means,
e. a locking means for holding said finger means and in an open
raised position, when said pivotal means is not operatively acting
upon said sliding and rotating means.
2. The transfer mechanism of claim 1, wherein said sliding and
rotating means comprises a first hollow shaft having an extending
flange at its were end and slidably mounted on a second central
shaft having detent surfaces at its lower end, a gear member
mounted on said shafts such that said shafts rotate integrally with
said gear member, and wherein said finger means comprises two
finger members pivotally mounted at the lower end of said hollow
shaft and acted upon by biasing springs to force the lower ends of
said finger members toward each other to a workpiece-contacting
position.
3. The transfer mechanism of claim 2, wherein said finger members
each have a protruding portion thereon such that when said first
hollow shaft is raised, said protruding portions pass into said
detent surfaces on said second shaft under the force of said
biasing springs to maintain said finger members in an open position
and said first shaft in a raised locked position.
4. The transfer mechanism of claim 2, wherein said pivotal means
comprises a second lever pivotally mounted on said frame and spring
biased such that one end of said second lever has upper and lower
abutment members thereon located adjacent said flange on said first
hollow shaft so that said abutment members can abut said flange to
lower and raise said first hollow shaft.
5. The transfer mechanism of claim 4, wherein the lower abutment
member is formed as part of said second lever and wherein the upper
abutment member comprises a third lever pivotally and slidably
mounted on said second lever and biased by plunger means located in
said second lever.
6. The transfer mechanism of claim 4, further comprising first
drive means which reciprocate said bracket means from a first to
second position and second cam drive means which act on said second
lever to cause said lever to pivot so as to lower and raise said
first hollow shaft in coordination with said first drive means.
7. The transfer mechanism of claim 2, further including rack means
positioned on said first lever means such that the first lever
means can slidably move relative to said rack means.
8. The transfer mechanism of claim 7, wherein said rack means
remain in constant contact with said gear member positioned on said
first and second shafts, such that upon rotation of said gears said
shafts are correspondingly rotated.
9. The transfer mechanism of claim 8, wherein said rack means
comprises a rack member mounted on said first lever means by pin
members which pass through slots in said rack member, such that
said first lever can slide relative to said rack member, and
wherein said rack member is pivotally connected to said frame by a
pivotal member which is pivotally connected at one to said rack
member and pivotally connected at the other end to said frame such
that upon reciprocation of said bracket means said rack member
moves only in a direction perpendicular to the longitudinal axis of
the rack member to continually stay in contact with the gear member
on said first and second shafts so that said shafts and finger
members thereon are correctly rotated.
10. The transfer mechanism of claim 7, wherein said first lever
means comprises two U-shaped members, wherein the two arms of said
members are pivotally connected to said bracket means and the
central portion of said members is pivotally connected to said
frame such that upon reciprocation of said U-shaped members said
members alternately abut stop means on said frame to accurately
position said bracket means.
11. A header, former or similar apparatus having a frame, a die bed
carried by said frame and having a plurality of dies on its face,
means for transferring the workpieces between adjacent dies,
comprising in combination
a. first lever means pivotally mounted on said frame,
b. bracket means pivotally mounted on said first lever means,
c. drive means for swinging said bracket means from a firs to a
second position,
d. rotating and sliding means having a gear thereon supported on
said bracket means,
e. finger means mounted on said rotating and sliding means and
capable of being in a workpiece-contacting closed position or an
open locked position,
f. lifting means pivotally mounted on said frame for acting on said
rotating and sliding means, and
g. cam means for engaging said lifting means to alternately move
said finger means from a closed workpiece-contacting position to a
raised locked position.
12. The header apparatus of claim 11, further including rack means
positioned on said first lever means such that said first lever
means are capable of sliding relative to said rack means, pivotal
means for connecting said rack means to said frame so that upon
swinging of said bracket means, said rack means moves only in a
direction perpendicular to its longitudinal axis to continually
remain in contact with said gear on said rotating and sliding
means.
13. The transfer mechanism of claim 8, wherein there are a
plurality of sliding and rotating means each having finger means
thereon and wherein at least one of said sliding and rotating means
does not have said gear member so that it will not rotate in
transferring a workpiece from one die station to the next.
Description
This invention relates to a transfer mechanism for a variety of
part-forming machines or headers and, more particularly, to means
for transferring a workpiece from one die station to another in
machines having a plurality of stations.
The present transfer mechanism may be employed either in a
multistation machine where a number of tools operate successively
upon the workpiece, or in a two-station machine where the workpiece
is conveyed from a first to a second die station.
In headers and in many part-forming machines, it is necessary to
have a transfer mechanism convey the workpiece from one station to
the next so as to accurately center the workpiece on the die at the
station to which it is transferred. It is desirable that the
workpiece be correctly positioned axially at the die station to
prevent breakage or undue wear of the tools. In some applications,
it is desirable that the workpiece be rotated or turned through an
angle of 180.degree. between die stations.
In prior art machines in which rotation of the workpiece is
accomplished, the finger means for gripping the workpiece are
usually tilted or raised, so that there is sufficient clearance
when the finger means are rotated. In the case where the finger
means are tilted, as substantially large number of parts have to be
placed on a single movable frame member which is moved in
coordination with the other operations of the machine.
In most transfer mechanisms, once the workpiece is transferred to
the next adjacent station, the finger means must open to release
the workpiece so that it may be positioned in the die. This is
accomplished by raising the finger means out of position so that
the work-forming punch may act on the workpiece without smashing
the finger means.
In the past, finger means constructed from intricate parts were
used. These finger means had the singular disadvantage in that they
could not be locked in an open raised position. As a result,
constant pressure had to be applied by appropriate connecting means
to maintain the finger means open against the force of biasing
springs which acted to close the finger means. Further, intricate
linkage means acted on the connecting means to maintain the finger
means in a raised open position during the return of the finger
means to their initial die station. As a result, part of the
linkage means had to travel between two positions in order to
maintain the finger means in a raised open position.
Accordingly, it is an object of this invention to provide a new and
improved transfer mechanism having finger means which can be
maintained in a raised locked position without the use of expensive
linkage means.
Another object of the invention is to provide a new and improved
transfer mechanism having simple pivotal means for moving the
finger means to an open or closed position.
A further object of the invention is to provide a new and improved
transfer mechanism having rotating means to rotate the workpiece
while it is being transferred from one die station to another,
wherein the finger means describe an arcuate path away from the
face of the die as it moves from one die station to another.
Still another object of the invention is to provide a new and
improved transfer mechanism having rack means which are engaged by
gear means connected to the finger means, such that the rack means
and the gear means remain in constant contact.
Yet a further object of the invention is to provide a new and
improved transfer mechanism which is mounted on a movable frame
member so that the transfer mechanism can be positioned for small
or large workpieces.
Still other objects and advantages of the invention will in part be
obvious and will in part appear from the specification.
In accordance with the above objects, the transfer mechanism of
this invention for a header finger similar apparatus comprises
first lever means pivotally connected to the frame of the
apparatus. Bracket means for supporting the positioning means are
pivotally mounted on the first lever means. First drive means act
upon the bracket means to reciprocate the bracket means along an
arcuate path. Rotating and sliding means having finger means
thereon are mounted on the bracket means. Pivotal means engaged by
second cam drive means act upon the rotating and sliding means to
raise or lower the finger means to an open or closed position. Rack
means are connected to the first lever means, such that the first
lever means can slide with respect to the rack means. Upon
reciprocation of the bracket means, the rack means move only in a
direction essentially perpendicular to its longitudinal axis so as
to remain in constant contact with a rotating gear on the rotating
and sliding means. The finger means comprise two finger members
pivotally mounted on the rotating and sliding means. The finger
members are spring biased at one end so that their free ends are
forced toward each other for gripping a workpiece. The rotating and
sliding means comprise a first hollow shaft slidably mounted on a
central shaft having detent surfaces at its lower end, so that when
the hollow shaft is in a raised position protruding portions on the
finger members pass into the detent surfaces to lock the first
hollow shaft in a raised position.
The invention accordingly comprises the features of construction,
combination of elements and arrangement of parts which will be
exemplified in the construction hereinafter set forth and the scope
of the invention will be indicated in the claims.
For a fuller understanding of the nature and objects of the
invention, reference is had to the following description taken in
connection with the accompanying drawings, in which
FIG. 1 is a front view of the transfer mechanism;
FIG. 2 is a partial top view of the transfer mechanism;
FIG. 3 is a sectional view taken along line 3--3 of FIG. 2;
FIG. 4 is a sectional view taken along line 4--4 of FIG. 3;
FIG. 5 is a sectional view taken along line 5--5 of FIG. 1;
FIG. 6 is a sectional view taken along line 6--6 of FIG. 5;
FIG. 7 is a side view similar to FIG. 6; and
FIG. 8 is a sectional view taken along line 8--8 of FIG. 7.
Referring to FIGS. 1-4, the transfer mechanism of this invention is
shown mounted on a header or like apparatus. A main drive shaft 10
has cam plates 12 and 14 thereon which act on followers 16 and 18
to pivot a lever member 20 pivotally mounted at 22 to the frame 24
of the apparatus. The lever 20 reciprocates a rod 26 which is
pivotally connected to the lever 20 through pivotal link 28. The
rod 26 reciprocates a bracket support member 30 through pivotal
connection 31. The drive shaft 10 also drives a shaft 32 through
bevel gear connection 33. Shaft 32 is connected to cam shaft 34 by
means of a flexible coupling 35 so as to continually rotate cam
plates 36 mounted thereon. The flexible coupling 35 permits shaft
34 to move in a direction transverse to its longitudinal axis with
respect to shaft 32 for reasons that will be explained below. A cam
plate is provided for each work station and workpiece positioning
means are supported on bracket member 30. The cam plates 36 are
positioned on rod 34 by support plates 38. The cam plates 36 engage
the pivotal means shown in detail in FIG. 5, which will be
explained in detail below.
In FIGS. 2-5, the bracket member 30 is shown pivotally connected to
lever members 40 by means of pins 42 which levers, in turn, are
pivotally connected to the movable frame member 43 by means of pins
44. The movable frame member 43 is supported on stationary frame
member 24 by bolts 43a passing through slots 43b. In this manner,
the frame member 43 may be positioned so that the transfer
mechanism supported thereon can accommodate the transfer and
rotation of either large or small workpieces from one die station
to the next.
During the reciprocation of bracket member 30, the travel of levers
40 is limited by stops 46 so as to correctly position the bracket
member 30 in its terminal positions. The reciprocation of the
bracket member 30 connected to levers 40 which are pivotally
connected to the frame 24, will cause the bracket member 30 to
describe an arcuate path during its movement, as shown by the
arrows 48. It can also be appreciated that the radius of the
arcuate path will depend on the length of the levers 40. The
bracket member 30 has a plurality of contoured surfaces 50 for
supporting members 52 by means of clamps 54, as seen in FIGS. 6 and
7. The members 52 support therein a central stationary shaft 56,
about which is slidably mounted a hollow shaft 58. The position of
the support member 52 as well as the shafts mounted thereon, can be
adjusted vertically by loosening clamps 54 and adjusting a threaded
bolt 60. The hollow shaft 58 is maintained in position by bearing
surfaces 62 so that it can slide against their surfaces. The
bearing surfaces 62 and roller bearings 64 are positioned to permit
the hollow shaft to rotate with a minimum of friction. The hollow
shaft 58 rests on support member 52 by means of nut members 66
threadably engaging the end of shaft 58. The nut members 66 rest on
washer 68 which, in turn, rests on a bearing surface 70. The
bearing surface 70 slides on rollers 72 which, in turn, can slide
on bearing surface 74 The bearing surface 74 is supported on a
sleeve 76 which rests on roller bearings 64. As a result of this
arrangement, when the hollow shaft 58 is rotated (in the position
shown in FIG. 6), the washer 68 will rotate with the shaft 58 with
a minimum of friction. A sleeve 78 is positioned adjacent the upper
portion of the hollow shaft 58. A gear 80 is mounted on the sleeve
78 by means of bolts 82. The sleeve 78 and central shaft 56 are
maintained in a stationary position relative to each other by means
of an elongated pin 84. The pin 84 also passes through longitudinal
slots 86 in shaft 58 so that the shaft 58 can move along its
longitudinal axis relative to gear 80 and central shaft 56.
However, the presence of pin 84 in slots 86 causes the shafts 56
and 58 to rotate in unison with gear 80. The lower end of the shaft
58 is formed with an extending flange section 88 and enlarged
supporting sections 89 on which are pivotally mounted finger
members 90. Protruding roller members 92 are mounted at the lower
end of finger members 90. Gripping members 93 are located on the
external side of the finger members 90 by means of pins 94, so that
they can grip the workpiece. Adjusting threaded members 96 are
positioned on the gripping members 93 so that the position of the
gripping members relative to finger members 90 can be adjusted.
Extending members 98 are attached to the upper end of finger
members 20 by means of a bolt 100. The members 98 are acted on by
springs 102 seated in openings 104. Biasing springs 102 act on
extending members 98 to force the gripping members 93 sufficiently
close to each other to grip a workpiece. Spring metal strips 106
are also attached to the finger members 90 by means of bolts 100 so
that the strips can maintain pins 94 in place during the normal
operation of the apparatus. However, if the apparatus should
malfunction so that the punch strikes the gripping members 93, the
members 93 will be torn loose from finger members 90 and damage to
the rest of the apparatus will be avoided.
When the lifting means, shown in FIG. 5, acts on the flange 88 to
raise the hollow shaft 58, the lower end of the stationary central
shaft 56 will force finger members 90 apart to an open position.
The rollers 92 permit the finger members to slide over the shaft 56
with a minimum of friction. When the shaft 58 has been raised to
the position shown in FIG. 7, rollers 92 pass into the detent
surfaces 108 in the central shaft 56. The force of the springs 102
acting on the finger members 90, is sufficient to lock hollow shaft
58 in the raised position with no other means acting upon it. The
lifting means, clearly seen in FIG. 5, comprises a lever 110
pivotally mounted on the frame 24 of the apparatus. The lever 110
has a follower 112 thereon which is forced against cam 36 by means
of biasing springs 114. The biasing springs 114 are connected at
one end to a rod 116 mounted on frame 24 and at the other end to
one side of lever 110 by means of a pin 118. The cam plate 36
causes lever 110 to pivot in timed relation to the reciprocation of
the bracket member 30. The other end of the ever 110 is formed with
an abutment member 120 for abutting the lower side of the flange 88
to raise shaft 58. An upper abutment member 122 is pivotally
mounted to lever 110 by means of a pin 124 which can slide in slot
126. A spring-biased plunger 128 acts on one side of abutment
member 122 to maintain it in an open position with respect to
member 120. The open position of abutment member 122 is limited by
the side of member 122 abutting shoulder 130 on the lever 110. In
this position the abutment member 122 can engage the upper portion
of flange 88 to lower the hollow shaft 58 to the position shown in
FIG. 6.
If the apparatus should malfunction, so that abutment member 122 is
located below the flange 88 when hollow shaft 58 is in a raised
position, then the abutment member 122 will not break when lever
110 is pivoted. The member 122 pivots and slides along slot 126
against the force of spring plunger 128. This prevents the breakage
of lever 110 so that the operator can shut down the machine and
correct the condition without extensive repairs. Further, since the
finger members 90 can lock shaft 58 in a raised position, it is not
necessary for lever 110 to follow the raised shaft from one die
station to another. As a result, the lever 110 does not move with
the reciprocation of bracket member 30.
A rack member 132 is mounted on the forward end of the levers 40 so
that it constantly engages gears 80 to rotate shafts 56 and 58
during reciprocation of the bracket member 30, It is necessary that
the gear 80 remain in constant contact with rack 132. During
reciprocation of bracket 30, gear 80 and shafts 56 and 58 describe
an arcuate path away from the face of the dies. This permits finger
members 90 to rotate 180.degree. as the workpiece is transferred
from one die station to the other without necessitating tilting or
raising of finger members 90 in order to provide sufficient
clearance for the rotation. In order for the rack member 132 to
stay in constant contact with gear 80, it is necessary that the
rack move with the gear when the bracket member 30 is reciprocated.
Also, to obtain accurate rotation of the shafts 56 and 58, it is
necessary that the rack member 132 remain stationary relative to
gear 80, so that the gears rotate along a relatively stationary
rack. This is accomplished by positioning rack member 132 about
recessed sections 134 of the sleeve members 136. The sleeve members
136 are located on the forward end of levers 40 about pins 42. The
rack member 132 has slots 138 therein along which sleeve members
136 can slide. Further, rack member 132 is connected to frame 24 by
means of a pivotal member 140. The member 140 is pivotally
connected to the frame 24 at one end by a pin 142 and to rack
member 132 at its other end by a pin 144, as viewed in FIGS. 3 and
4. When rack member 132 is at its innermost position, such that it
abuts stops 146 on frame 24, the pin connection 142 is forward of
pin connection 144. Thus, when the levers 40 are pivoted to the
right, the rack member 132 will only move forward and back in a
direction perpendicular to the longitudinal axis of the rack, as
shown by the arrows 148. This movement will be repeated when levers
40 move from right to left. It can be appreciated that, with this
means for supporting rack member 132, the gears 80 will stay in
constant contact with rack member 132. Further, rack member 132
will remain stationary relative to the rotation of the gears. It
can also be appreciated that, by simply eliminating the gear 80
about some of the shaft 56, 58 such modified shafts should be
secured so that they will not rotate when a work piece is
transferred by them from station to station.
The present apparatus may, therefore, be used with a machine when
it is desirable to transfer between certain stations without
rotation but to rotate or turn the workpiece between other
stations. A header or like machine may be constructed in accordance
with the present invention, wherein either type of transfer
mechanism may be provided selectively at any or all of the several
stations by a relatively simple substitution of parts. The transfer
mechanism may be adapted to rotate the workpiece between any two
adjacent stations where rotation is desired and to effect transfer
of a workpiece with rotation between other stations.
It can be further appreciated that the transfer mechanism disclosed
is constructed from fewer and simpler parts which operate in a more
efficient manner than the transfer mechanisms of the prior art.
Moreover, if it is desired, the transfer mechanism is mounted on
movable frame member 43, as explained previously. By simply
loosening bolts 43a, the frame member 43 can be moved to the
desired position and the bolts tightened so as to lock frame member
43 onto frame 24. Thus, by this simple means, the initial distance
of transfer fingers 90 from the frame of the dies may be adjusted
to accommodate the rotational transfer of either small or large
workpieces.
It will thus be seen that the objects set forth above, among those
made apparent from the preceding description, are efficiently
attained and since certain changes may be made in the above
construction without departing from the spirit and scope of the
invention, it is intended that all matter contained in the
foregoing description or shown in the accompanying drawings shall
be interpreted as illustrative and not in a limiting sense.
* * * * *