Note: Descriptions are shown in the official language in which they were submitted.
This application is a divisional of Canadian
patent application no. 493,464, filed Ocotber 21, 1985.
The invention relates to a method and apparatus
for producing bodies of revolu-tion having at least one
groove which extends substantially in the peripheral
direction thereof and whose width, extending in the axial
direction of the body of revolution, decreases towards the
floor of the groove, wherein during rotation of a blank about
its longitudinal axis, a pressure which exceeds the yield
point of the material of the blank is locally applied.
The previously known methods of that kind
provided for impressing a shaped rib into the blank as it
rotated, the width of the rib, as considered in the
direction of forward feed motion, increasing from a
minimum value to a maximum value and the height thereof
also increasing. In other words, in order to produce for
example a V-shaped groove, the previous method involved
using a shaped rib which was impressed with its tip
leading into the rotating blank, the rib increasing in
width and height in the course of the forward feed motion.
The disadvantage of such a method of manufacture
is that the fact that the tip of the shaped rib was
impressed into the material caused the material to undergo
hardening, and the hardened region had to be further
deformed, so that correspondingly high pressures are
required and overloading of the material and thus cracking
thereof may very easily occur.
It is an objec-t of the invention to overcome
these disadvantages and to propose a rnethod of the kind
set forth above which avoids further deformation of
regions of the workpiece which have already been severely
deformed.
According to one aspect of the invention, there
is thus provided a method of producing bodies of
revolution having at least one groove which extends
substantially in the peripheral direction thereoC and
whose width, extending in the axial direction of the body
of revolution, decreases towards the floor of the groove,
wherein, during rotation of a blank about its longitudinal
axis, a pressure which exceeds the yield point of the
material of the blank is locally applied, characterised in
that the width of action of the pressure is reduced from a
width corresponding to the width of the groove to be
produced at the peripheral surface of the blank, to the
width of the floor of the groove to be produced, in
accordance with the progressing depth of impression, the
reduction in the width of impression, with progressing
depth of impression, being effected in accordance with the
inclination of the walls of the groove.
That provides that it is only ever the regions
which have been less deformed, that are subjected to
further deformation, and extreme levels of hardening and
consolidation of the material are avoided. In addition,
deformation of the blanks in that way requires a smaller
amount of energy. When producing screwthreads by means of
the method according to the invention, in accordance with
a further feature of the invention, it may be provided
-- 2 --
~æ~
that the screwthread groove is impressed into a blank
which is of the outside diameter of the desired
screwthread. The materi.al which is pressed out of the
screwthread groove in tha-t operation is displaced in the
axial direction so that the finished screwthreaded pin or
bolt is greater in length than the blank used for that
purpose.
In relation to screwthreads, in particular
trapezoidal screwthreads or the like, there is the
advantage, when using blanks which are of the outside
diameter, that the material does not have to flow up the
flanks of the screwthread in order completely to build up
the screwthread flights or ribs, which in certain
circumstances can result in overloading of the material
and cracking at the peripheral surface of the screwthread
flights, but the material can only flow axially, thereby
ensuring that the screwthreads flights consist of solid
material and cannot have any cracks or cavities which are
covered by material which is displaced in an outward
direction.
The present invention also provides,in another
aspect thereof, an apparatus for carrying out a method as
defined above.
In an apparatus comprising at least one roller
which cooperates with a cooperating pressure surface and
which is movable relative thereto, it is therefore
proposed, in accordance with the invention, that the width
of the shaped rib or ribs decreases in the direction of
the relative movement between the roller and the
cooperating pressure surface, and the height thereof
- 3 -
55i
increases. That ensures tha-t, when producing a peripheral
groove or the like, the blank is first acted upon, wi-th
the maximum wid~h of the groove to be produced, ~7hile the
width of impression progressively decreases and the depth
of impression increases in the course of produc-tion.
Another possible configuration of an apparatus
for carrying out the method according to the invention
provides that, in an apparatus comprising two rollers
which can be driven in mutually opposite directions of
rotation and of which at least one is provided with a
raised shaped rib and between which there is a roll gap,
in accordance with another feature of the invention the
rib is of decreasing width and increasing height in the
direction of rotation of the roller. Such an apparatus
also ensures that the pressure firstly acts on the blank
with the greatest width of the groove to be produced, and
the width of action decreases as the groove is impressed
in the blank. In accordance with a further feature of the
invention, it may be provided that shaped ribs are
disposed both on a drivable central roller and on the
cooperating surface which is subdivided into segments,
which ribs cross each other in the course of the mutual
relative moment.
Those features make it possible for the
counterpressure surface to be advanced to a greater or
lesser degree towards the central roller, as required,
without thereby giving rise to a roll or operative gap
which varies over its arcuate length. That is due to the
fact that the mutually crossing ribs only co-operate along
the generatrices of the central roller and the counter-
pressure surface, which pass through the point ofintersection of the ribs, and thus apply the necessary
pressure to the blank.
In that connec-tion, it is advan-tayeous for the
segments of the counterpressure surface to be arranged on
carriages which are guided displaceably radially with
respect to the central roller and which are movable
preferably independently of each other by means of a
control drive. In that way, it is possible to take
account of wear of the ribs but also differences both in
the dimensions of the blank and also in the properties of
the material thereof.
It may also be provided that -the control drive of
the carriages is connected to a measuring means for
measuring the articles when in the finally deformed
condition and displaces the carriages in dependence on the
detected measurement data, thereby providing for automatic
adjustment of the counterpressure surface. Thus, it may
be provided that random samples of the articles produced
~0 are taken from the stream leaving the apparatus, measured
in the measuring means and compared to a predetermined
tolerance range and the carriages carrying the counter-
pressure surface are adjusted such that the produced
articles lie in the middle of the tolerance range.
It is fully possible for one of the mutually
crossing ribs to be disposed perpendicularly to the axis
of the central roller, but in that case the central roller
and the counterpressure surface, besides the relative
rotary movement, must also perform a relative movement
having a component in the axial direction of the roller.
-- 5
In order to avoid that additional movement which,
in that case, can be controlled in any desired manner, and
in order thereby to permit the apparatus to be simpler in
construction, it may be provided, in accordance with a
further feature of the invention, that each of the
mutually crossing ribs of the central roller and the
co-operating surface extend at an inclined angle with
respect to the axis of the central roller. That
arrangement ensures that the ribs constantly intersect
each other during the rotary movement of the central
roller, if we disregard an intake and discharge region of
the apparatus, for the feed of blanks and the discharge of
finished articles, which region is kept free of ribs.
In order to ensure precise entrainment -and
guidance of the blanks during processing thereof between
the central roller and the counterpressure surface, a
further feature of the invention may provide that the
central roller is drivingly connected by way of trans-
mission means to an entrainment means for the blank, which
entrainment means has at least one but preferably two
rotary members which are spaced from each other in the
axial direction of the central roller and in which push
rods or thrust members are held displaceably in the
longitudinal direction thereof and engage by means of a
sliding member or the like in a peripheral control groove
which is disposed in a stationary part of the apparatus,
wherein the thrust members which are guided in two
different rotary members are axially aligned with each
other. Those features provide that the blanks are clamped
and thus entrained between the thrust member and a cam,
~æ~
but better between a respective pair of mutually axially
aligned thrust members. In that arrangement, it may
further be provided that the control groove, with -the
exception of a feed and discharge region for the blanks
and the finished bodies of revolution respectively,
extends substantially parallel to the path of the points
of intersection of the ribs of the central roller and the
counterpressure surface during the rotary movement of the
roller, wherein the control grooves which are associated
with the thrust members guided in both rotary members
extend parallel to each other in that region, thereby
ensuring a precise guidance action for the blanks and easy
feed of the blanks and removal of the finished bodies of
revolution.
When producing bodies of revolution with
peripheral grooves, additional compacting or consolidation
in the region of the walls of the groove may be desired in
some cases. In such a situation, the control groove may
be inclined with respect to the imaginary line which is
formed from the path of the points of intersection of the
ribs of the central roller and the counterpressure
surface. By virtue of that arrangement, the ribs press
not only radially against the blank but also axially
against the walls of the groove which are being formed.
A preferred embodiment of an apparatus according
to the invention further provides that at least the
mutually facing end regions of the thrust members are
arranged to be rotatable about the longitudinal axis of
the thrust members, wherein preferably the end regions
of the one thrust members are spring-loaded relative to
the coaxially aligned thrust members. That avoids friction
between the end faces of the blanks and the thrust members.
By virtue of -the end regions of the one thrust members
being resiliently supported, that arrangement eliminates
excessive pressure against the blank being processed when
the blank grows in the axial direction due to the groove
being impressed therein. In addition, that arrangement
also makes it possible to compensate for dimensional
variations in the blanks. The end regions of the thrust
members may be formed by inserts.
In accordance with a further feature of the
invention, it may also be provided that provided for the
entrainment means is a ring gear or spur gear which is
non-rotatably connected to the central roller and into
which engage gear transmissions drivingly connected to
support shafts disposed parallel to the thrust members,
wherein the support shafts are held in the rotary members
guiding the thrust members, or rotary members which are
non-rotatably connected thereto.
~0 Those features provide that the blanks are driven
during the operation of processing same, while, by virtue
of suitable matching of the gear transmissions, the
peripheral speeds of the central roller and the blanks can
be matched to each other.
Further features and advantages of the invention
will become more readily apparent from the following
description of the preferred embodiments as illustrated by
way of examples in the accompanying drawings, in which:
Figures lA and lB diagrammatically show tools for
carrying out the method according to -the invention and
deformation of a blank using such tools,
~æ~
Figure 2 shows the development of the shaped ribs
of the tools shown in Figures lA and lB,
Flgure 3 is a view in vertical section of an
embodiment of an apparatus for carrying out the method
according to the inven-tion,
Figure ~ is a plan view of the apparatus shown in
Figure 3,
Figure 5 is a detail of the apparatus shown in
Figures 3 and 4 on a larger scale,
Figure 6 is a detail of the thrust member guide
arrangement of the apparatus shown in Figures 3 and 4, on
an enlarged scale,
Figure 7 shows a further detail of the thrust
members,
Figure 8 is an exploded view of the entrainment
means of the apparatus shown in Figures 3 and 4,
Figure 9 is a front view of the entrainment
means, and
Figure 10 is a plan view of the entrainment
means.
Figure lA is a diagrammatic view of the shaped
ribs 7 and 8 which are disposed on the counterpressure
surface 1 which is subdivided into five segments 2, 3, 4,
5 and 6. The rib 7 serves to form the step or shoulder 10
of the finished article 9v produced from the blank 9. On
the other hand, the rib 8 serves to form out the groove 11
of the finished article and has its maximum width and
minimum height at the beginning of the counterpressure
surface or at the boundary of the intake region for the
blanks 9 which are to be handled. Along its path from the
beginning of the rib 8 to the end thereof at the edge of
the segment 6 which, as will be described hereinafter, is
the trailing edge as considered in the direction of
rotation of a central roller, the width of the rib 8
progressively decreases and it terminates in a form which
is equal and opposite to the groove 10.
The central roller 12 shown in Figure lB runs in
the space enclosed by the segments 2 to 6 of the
counterpressure surface, but was not shown jointly
therewith, for the sake of enhanced clarity of the
drawings. The roller 12 is installed in such a way that,
in a position of the roller 12 relative to the segments 2
to 6 of the counterpressure surface 1 in which the
beginnings of the ribs 7' and 8' are radially aligned with
. the beginnings of the ribs 7 and 8, they are also at the
same height.
The change in the cross-sectional form of the rib
8 from segment to segment or from segment boundary to
segment boundary can be clearly seen from the change in
the configuration of the blank 9, to give the finished
article. Thus, the intermediate product 9' corresponds to
the condition of deformation of the blanl~ 9, as occurs at
the boundary xl between the segment 2 and the segment 3.
That shows the cross-sectional form of the ribs in that
cross-section. In the same fashion, the intermediate
product 9" corresponds to the condition of deformation of
the blank in the cross-section x2, the intermediate
product 9"' corresponds to the condition of deformation
of the blank at the cross-section x3 and the intermediate
-- 1 0 --
~iEi~55
product 9iv corresponds to the condition of deforrna-tion a-t
the cross-section x4. In cross--sec-tion xS, the blank is
formed to give the finished body of revolutlon 9V.
It will be clearly seen from the for~ of the
intermediate products 9,, 9., 9,,, 9iv 9v th
and the ribs 8' (Figure lb), from their beginning,
decrease in respect of their width at their location of
greatest height, in their respective cross-section,
whereas the ribs 7 and 7' increase in width.
It will also be seen from figure lA tha-t during
processing the blanks 9 are held between two thrust
members or pushrods 14 and 14' which separate from each
other in the intake and discharge region which is between
the cross-sections 5x and x, and thus enable the blanks 9
to be introduced and the finished articles to be removed,
such operations occurring in different planes.
Figure lB diagrammatically shows the central
roller 12 which co-operates with the counterpressure
surface 1. The roller 12 is provided with two shaped ribs
7' and 8' which correspond to the ribs 7 and 8 but which
are inclined in the opposite direction to the ribs 7 and 8
so that when the central roller 12 is fitted between the
segments 2 to 6, the ribs 7, 7' and 8, 8' respectively
cross each other when the central roller 12 rotates in the
direction indicated by the arrow 13.
As can be seen from Figure 2 which shows a
development of the ribs 7, 8, 7' and 8', the ribs 7' and
8' are moved past the ribs 7 and 8 in the direction
indicated by the arrow 13, whereby the points of
intersection of the ribs move inclinedly downwardly
-- 11 --
~ 55
towards the right. In that arrangement, the blank 9 is
guided by the two thrust members 14 and 14' substantially
along the line which corresponds to the geometrical locus
of the points of intersection of the ribs 8 and 8' during
the relative movement of the ribs 7 and 8 with respect to
the ribs 7' and 8'.
The thrust members 14 and 14' are guided between
the boundaries x and x5 of the segments of the surface 1
along the imaginary base lines 15 and 15' which are shown
in dash-dotted form and which extend parallel to the ribs
8 and 8'. The lines 15 and 15' are slightly inclined with
respect to the line corresponding to the geometrical locus
of the points of intersection, thereby taking account of
the axial growth in length of the blank 9 due to the
groove 11 being impressed therein.
It will be appreciated that the blanks 9 are not
guided along two different paths, but the dash--dotted
lines 15 only indicate the path of the blanks with respect
to the ribs 7, 8 and 7' and 8' respectively. In practice,
as will be described in greater detail hereinafter, the
blanks are in principle controlled by a groove which is
provided in a stationary part of the machine and the
configuration of which substantially corresponds to that
of the rib 8.
With the above-described arrangement, as
considered from the central roller 12, the path of
movement of the blank is parallel to the rib 8'.
As can be seen from Figures lB and 2, the
cross-sectlonal shape of the ribs 7' and 8' also alters in
the same fashion as that of the ribs 7' and 8', that is to
- 12 -
~æ~
say, the rib 8' increases in heiyht Erom its beginning to
its end and decreases in width in the region of its
maximum height.
Figure 3 is a diagrammatic view of an apparatus
for carrying out the method according to the invention, in
vertical section, in which in particular the mounting and
bearing means and the installation thereof are shown in
simplified form. In addition, structural groups and
units, which, for manufacturing reasons and for reasons of
greater ease of assembly, consist of a number of parts,
are shown in part as being formed as one part.
The drive motor 20 drives a shaft 23 by way of a
clutch 21 of which one half is connected to a flywheel 22.
The shaft 23 is supported in the housing 26 in convention-
al manner by way of the rolling bearings 24 and 25 and is
non-rotatably connected to a bevel gear 27 and a chain
wheel 29.
The bevel gear 27 meshes with a further bevel
gear 28 which is non-rotatably connected to a vertically
disposed main shaft 30. The main shaft 30 is held by
means of two tapered roller bearings 31 and 32 in a
carrier cylinder 33 connected to the housing 26.
A first guide member 34 is fitted on the cylinder
33 and is rigidly connected thereto. In addition,
disposed on the cylinder 33 is a needle beaxing 35 which
is axially fixed in position by the guide member 34 and a
support~ flange 36, and which rotatably mounts a rotary
member 37 provided with a chain ring 38. The rotary
member 37 or the chain ring 38 thereof is connected by way
of two chains 39 to chain wheels 40 which are non-rotata-
- 13 -
bly connected to the output shaft 41 of a transmission 42.
The transmission 42 is driven by way of two chains 44 and
chain wheels 43 by the shaft ~3 or the chain wheels 29
connected thereto, and is held in the housing 26' by way
of a bracket 46.
The rotary member 37 is connected by way of pins
45 to a further rotary member 47 and is mounted to the
main shaft 30 by way of a rolling bearing 48. The two
rotary members 37 and 47 are also connected together by
way of slotted guide sleeves 49 in which the thrust
members 14' or the guide heads 50 thereof are axially
slidably guided. The guide heads 50 engage with their
rotatably mounted roller 51 into a control groove in the
guide member 43.
The thrust members 14' pass through the rotary
member 47 and are guided therein in bushes 53. In
addition, secured to the rotary member 47 is a splash ring
54 which serves to carry the oil used for lubrication
purposes away into an annularly disposed oil sump (not
shown).
The rotary member 47 is connected to a further
rotary member 56 by way of struts S5. Like the rotary
member 47, the rotary member 56 is provided with
tangentially extending portions of dovetail guides which
serve to accomodate sliding members which are parts of the
entrainment means shown in Figures 8 to 10 and are
described hereinafter with reference to those Figures.
For the sake of enhanced clarity of the drawing, the
corresponding reference numerals are not shown in Figure
3.
- 14 -
~2~
Non-ro-tatably disposed on the main shaft 30 is a
chuck body 57 on to which is fitted the roller 12 which
bears the ribs 7' and 8', beinq held in position
non-rotatably by means of a key and groove connection.
Screwed to the roller 12 is a ring gear or spur gear 58
from which the drive for the entrainment means is derived,
as will be described in greater detail hereinafter with
reference to Figures 8 and 10.
A sleeve 59 is fitted on a stepped portion of the
main shaft 30 and non-rotatably connected thereto by way
of a key and groove connection. Mounted on the sleeve 59
by way of a rolling bearing 60 is a rotary member 62 which
is screwed to an internal ring gear 61. As can be seen
from Figure 5, the ring gear 61 meshes with intermediate
gears 63 which in turn mesh with further gears 64 which
serve only to reverse the direction of rotation and which,
like the intermediate gears 63, are mounted rotatably in a
ring 66 disposed in the in-terior of a further guide member
65 which is fixed with respect to the housing. The gears
64 in turn mesh with a ring gear which is disposed on the
sleeve 59 and which provides for the drive for the rotary
member 62 by way of the gears 63 and 64 and the ring gear
61 which supports the guide member 65 by way of a rolling
bearing 60'.
The rotary member 62 is connected by way of pins
67 and a sleeve 68 to a ring 69 in which are mounted
bushes 53 in which the thrust members 14 are rotatably and
axially displaceably guided, just as in the rotary member
62.
- 15 -
The guide member 65 is of a two-part construction
and supports the main shaft 30 by way of a rolling bearing
69'. In addition, the guide mernber 65 is provided with a
control groove 70 into which engages a rotatable roller 51
carried in each guide head 71 of the thrust rnembers 14, as
shown on a larger scale in Figure 6. As shown in Figure
6, the pin 72 carrying the roller 51 engages with an
extension portion into a peripheral groove 73 in the
thrust member 14 whereby the latter is mounted ro-tatably
but axially displaceably in the guide head 71.
Over the major part of the periphery of the guide
member 65, the control groove 70 extends parallel to the
control groove 52 of the guide member 34. It is only in
the intake and discharge region which was described with
reference to Figure lA that the above-indicated parallel
condition does not occur and in that region the two
control grooves move apart and back towards each other
again.
The guide member 65 can be connected by way of a
flanged member 74 to a support arm 75 in which the main
shaft 30 is supported in a plain bearing. The support arm
75 is supported on a carrrier pillar 76 which is fixed on
the housing 26'. Disposed in the pillar 76 is a spindle
77 which is supported relative to the inside wall surface
of the pillar 76 and relative to a cylindrical bore 79 of
the support arm 75 by means of a centering ring 78 in its
upper region. The support arm 75 is clamped to the pillar
76 by means of a nut 80.
- 16 -
After unscrewing and removing the nut 80 and
releasing -the connection between the flanged member 74 and
the support arm 75, the la-tter can be lifted and pivoted
whereby it is possible to dismantle the apparatus, in
order for example to replace the roller 12 by another
roller with ribs of a different configuration in order to
be able to produce different bodies of revolution.
Also arranged on the housing 26' are five
carriages 81 which carry the segments 2 to 6 of the
co-operating surface 1. The carriages 81 are guided in
housings 82 in each of which is disposed a screw-threaded
spindle 84 supported in a bearing arrangement 83
comprising thrust and radial rolling bearings. The
spindle- 84 is driven by a stepping motor 86 by way of a
transmission 85 and it passes through two nuts 87 which
are braced relative to each other to compensate for play
at the spindle, which in turn is connected to the carriage
or slide body 88 which is guided in the housing 82 and
which incorporates a weak location 89 for carrying wire
strain gauges.
Mounted at the end of the body 88 is an
adjustable-height support, which, together with -the
adjusting spindle associated therewith, is generally
denoted by reference numeral 90. Secured to the support
90 is a segment of the co-operating surface 1 which bears
the ribs 7 and 8.
- 17 -
A peripheral cam 92 i5 mounted to the carriayes
81 and the pillar 76 by way of mounting arms 91. As will
be described in greater detail hereinaf-ter with reference
to Figures 8 and 9, the cam g2 is provided for controlling
the entrainment means.
The feed means for the blanks to be worked upon,
which can be better seen from Figure 4, is indicated
generally by reference numeral 93 and is driven by the
transmission 42 by way of a chain wheel 94 and a chain 95.
The step-up ratio of the transmission 42 and the
chain wheels 40 and 38 as well as that of the transmission
formed by the ring gear 61 and the ring gear of the sleeve
S9 and the gears 63 and 64 is such that the rotary members
which are driven by those transmissions, on the path of
movement described by the thrust members 14 and 14' which
are mounted in the rotary members, move at half the
peripheral speed of the peripheral surface of the roller
bearing the ribs.
In the carriage 81.shown in section in Figure 4,
a vibration generator 96 is screwed into the segment of
the counterpressure surface 1 and causes the counter-
pressure surface to be displaced with high-frequency
vibrations or oscillations, thereby facilitating
deformation of the blanks 9 which are guided between the
segments of the surface 1 and the roller 12 by means of an
entrainment arrangement which is not shown in Figure 4 for
the sake of enhanced clarity of the drawing.
As can be seen from Figure 4, the supply means 93
has an inclinedly extending channel 97 which guides the
blanks 9 into the star wheel 98~ The star wheel 98
- 18 -
~6~;5
transports the blanks to a further star wheel 99, ~"hile
for the purposes of transferring the blanks -the arranye-
ment includes a yuide plate 100 which is secured to the
housiny 26' by way of a holder which is not shown for the
sake of enhanced clari-ty of the drawinys.
Punches 101 of which only two are illustrated are
yuided in the star wheel 99 which rotates in a plane which
is displaced with respect to the star wheel 98. The
punches 101 project beyond the upper face of the star
wheel 99 and slide ayainst the cam 102. The cam 102 which
is stationary causes the blanks to be pushed out into the
path of the thrust members 14 and 14' by which they are
engaged or clamped.
Disposed in a horizontal plane which is different
from that of the feed means is a magnet 103 which, after
the finished bodies of revolution 9v are released by the
thrust members 14 and 14', conducts them into a further
channel 104.
Incorporated into the channel 104 is a switching
means 105 which permits a body of revolution to be
selectively removed from the channel by a deflection plate
106 being inserted thereinto by means of the piston-
cylinder arrangement 107. The body of revolution which is
removed from the channel in that way then passes by way of
a channel 108 to a measuring device 109 in which the body
of revolution is pushed by means of a piston 110 into a
measuring position in which it bears against an abutment
111 which is pivotable by means of a pi~ston-cylinder
arrangement 112. The measuring operation itself is
carried out by means of an optical measuring head 113
-- 19 --
which produces the measuring result in the form of
electrical signals which are passed to a control means
(not shown) for example a process computer. In the case
where the measurement values obtained are towards -the
limits of a predetermined tolerance range, the control
means passes suitable control instructions to the stepping
motors 86 of the carriages 81, to provide for suitable
adjustment thereof. That makes it possible to observe
very close tolerances.
After the operation of measuring the body of
revolution, the abutment 111 is pivoted by the piston-
cylinder arrangement 112 and the piston-cylinder
arrangement 110 pushes the body of revolution which has
already been measured to the opening 114 through which it
slips to the exterior by way of the channel 115.
Figure 7 shows the end regions of the members 14
and 14' on an enlarged scale, said end regions being
rotatable about the longitudinal axis of the members 14
and 14'. In that arrangement, screwed into the thrust
member 14 in the end thereof is an insert 116 in which a
tip 117 is held by means of a pin 119 which passes through
a transverse 118 and the tip 117 and which also passes
through the walls of the insert 116. The tip 117 is
axially displaceably held in the insert 116 and is
subjected to the force of a spring 146. As the transverse
bore 118 is larger in diameter than the tip, this
arrangement provides for a slight amount of axial
displacement of the tip 117 relative to the insert or the
casing thereof. That makes it possible to compensate for
slight dimensional variations in the blan]cs 9 and to
- 20 -
LS5
compensate for the growth in length of the blanks while
they are being deformed by the ribs 7, 8 and 7', 8'
respectively of the counterpressure surface 1 and the
roller 12.
A sleeve 121 is screwed on to the screwthreaded
spigot 120 of the trust member 14'. A slide bush 122 is
fitted into the sleeve 121 and secured therein with an
insert member 123. A tip 124 is rotatably carried in the
bush 122, the collar on the tip being supported against a
slide ring 125 which in turn is supported against a
shoulder of the sleeve 121.
The arrangement of the rotatable tip 124 of the
thrust members 14' and the rotatable mounting of the
thrust members 14 in the guide heads 71 thereof ensures
that friction between the thrust members 14, 14' and the
blanks 9 which are held therebetween is eliminated.
The entrainment means will be described in
greater detail with reference to Figures 8, 9 and 10.
The rotary members 47 and 56 are provided in a
section-wise manner with tangentially extending, radially
projectlng dovetail guides 126. Two slide members 127 are
displaceably disposed on each of the sections of the
dovetail guides. The thrust members 14 and 14' pass
between the projections on the rotary members whereas the
support rollers 128 are rotatabl~ mounted in the bores 129
of the slide members 127. The slide members 127 which are
mounted in different rotary members 47 and 56 respectively
are connected together by way of the pressure members 130
which are screwed to the slide members 127.
- 21 -
The members 130 are controlled by respective cam
shafts 131 whose cylindrical projections 132 extend
through and are rotatably mounted in the bores 133
disposed in the radially projec-tiny portions of -the
rotatary members 47 and 56. The upper cylindrical
projections 132 are each non rotatably clamped in a
respective control lever 134 while the projections 132
engage into the bores 135 which define a slot 136. The
control levers 134 slide along the stationary cam 92 upon
rotary movement of the two rotary members 47 and 56.
Over the arcuate region over which the counter-
pressure surface 1 extendsr the cam 92 describes
substantially a circular arc. In the region of the feed
and discharge area for the blanks 9 and the finished
bodies of revolution respectively, the cam 92 has a
depression 137 which permits pivotal movement of the
control levers.
The support rollers 128 have a region which is
provided with knurling and which comes into contact with
~ and drives the bla'nks 9. The support rollers are driven
by the gears 138 which are non-rotatably connected to the
support rollers. The gears 138 mesh with intermediate
gears 139 which are rotatably mounted with a respective
gear 138 in a holder 140, the intermediate gears 139
meshing with the gear 58 connected to the roller 12
carrying the ribs 7' and 8'. In that arrangement, because
of the difference in speed between the gear 58 and the
holders 140 which are also moved by virtue of the driving
connection to the rotary members 47 and 56 which is
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provided by -the support shafts 128, a rolling movement of
the intermediate gears 139 is produced and thus -the
support shafts are driven.
As can be seer, from Figures 9 and 10, the
respectively associated holders 140 are connected -together
by a pin 141, with the two holders 140 being braced
towards each other by two springs 142.
As long as the control levers 134 slide along -the
arcuate region of the cam 94, they are deflected and the
cam shafts 131 which are non-rotatably connected thereto
urge the members 130 and the support shafts 128 which are
held therewith in the slide members 127 against
the thrust members 14 and 14' and thus against -the blanks
9 to be deformed. When that happens, the holders 140 are
urged apart against the force of the springs 142. When
one of the control levers 134 slides into the depression
in the cam, that control lever can be deflected and the
springs 142 can urge the support shaf-ts 128 away from the
thrust members whereby, by way of the pivotal movement of
the cam shaft 131, the control lever 134 is also caused to
pivot, being held in contact with the cam 92 by the
springs 142.
As can be seen from Figure 10, the intermediate
gears 39 rotate in two different horizontal planes and are
rotatably fixed on axle journals which are held at one end
in the respective holders 140. The step-up ratio of the
transmissions 58, 139, 138 and the support shaft 128 or the
diameter of the knurled region thereof are matched to each
other in such a way that the peripheral speed of the
knurled region of the support shafts 128 and thus also
that of the blanks 9 bearing thereagainst is equal to the
peripheral speed of the periphery of -the roller 12
carrying the ribs. Although the blanks 9 are caused to
rotate solely by the rolling movement against the
stationary co-operating surface 1 and the peripheral
surface of the roller 12, as indicated by the arrows in
Figure 10, nonetheless a certain sliding movement of the
blank against such surfaces may also occur during working
of the blank. That is prevented by the additional drive
for the blanks by the support shafts, while, as can be
seen from Figure 10, the blank 9 is always supported and
driven between the support shafts 128 which are mounted in
adjacent pairs of holders 140.
As can be seen from Figure 8, the pressure
members 130 have a groove which is towards the support
shafts 128 and which extends in the axial direction and in
which are disposed rolling members 144 which project
beyond the outer edges of the groove 145. That subs-
tantially eliminates friction between the support shafts
and the pressure members 130.
When the control levers 134 go from the arcuate
region of the cam 92 into the depression 137 therein, the
intermediate gears 139 also perform an additional movement
relative to the gear 58, by virtue of the two holders 140
connected by the pin 141 moving towards each other, due to
the springs 142. Although that additional movement
results in a change in the speed of rotation of the
support shafts, that is however of no importance as in
that situation the support shafts 128 are moved away from
the blank 9.
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~i6~i
The control grooves 52 and 70 which determine the
path of the blanks 9 extend as indicated by the line 15 in
Figure lA or parallel thereto, in the region covered by
the co-operating surface l. Outside that region, the
paths of the control grooves have deviations in opposite
directions, the control grooves 52 and 70 moving further
apart from each other and moving towards each other ayain
so that in that region there is no clamping in respect of
the blanks 9 or the bodies of revolution gv and the blanks
can be introduced and the finished bodles of revolution
can be removed.
In the illustrated embodiment, the co-operating
surface l is of a curved configuration corresponding to
the roller 12, but that is in no way absolutely necessary.
Thus, it is also possible to use a flat counterpressure
surface over which the roller moves, in which respect it
is irrelevant whether the counterpressure surface is moved
with respect to the axis of the roller or whether the
roller is moved in parallel relationship with the
counterpressure surface.
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