Note: Descriptions are shown in the official language in which they were submitted.
2l6~n~2
Description
Tool for rotating rotatable connecting elements, method of
rotating and in part;c~ r loos~n;ng rotatable connecting
elements, and a rotatable connecting element
The invention concerns a tool for rotating rotatable connecting
elements, a method of rotating and in part;clll~r loosening rotatable
connecting elements, and a rotatable connecting element. The tool has a
head portion which can be fitted on to the connecting element, with an
internal opening for receiving the head of the connecting element.
Those tools include all hand-operated or ~h;ne-driven socket
wrenches, for example box wrenches, spark plug wrenches, wheel nut
wrenches or machine-operated power socket wrenches. Torque wrenches,
starter block wrenches and insert rings for fre~ ~l ratchets and all
kinds of open-ended or jaw-type wrenches and ring spanners, for example
divided ring spanners (also referred to as brake line spanners or
wrenches) are included among the tools which are within the scope of the
present invention. In general the invention can be used in relation to
any tool which is suitable for rotating rotatable and in particular
screwable connecting elements, in particular polygonal screw members,
nuts or round connecting elements such as screw bolts or studs, and has
a head ~ortion which can be fitted on to the head of the connecting
element and which has a suitably profiled internal oppn;ng. In that
connection the tools may also be of a multi-part construction and for
example ;ncll~e the socket wrench inserts as well as the associated
drives, ratchets, jointed handles and the like.
In general the internal op~n;ng in the head portion of the tool
is of such a configuration that it is suited to the generally
standardised external contour of the screw which is to be loosened or
screwed fast. For example, in the case of socket wrench inserts (also
referred to as socket tools) when designed for c~l~lleLcially av~ hl e
hex~n~l screws, it has sixortwelve inside wall surfaces which extend in
a straight line, in which case the screw to be screwed bears with the
2163052
_ 2
edges of its screw head in the angle regions of the internal opening.
When the tool is operated the turning force is thus ~pl;e~ to the
screw by way of the outer edge regions of the screw head. The same also
~pl;~s in the case of ring spanners or wrenches whose internal opening
passes completely through the head portion, and also for open-end
wrenches which generally have two jaws with surfaces which extend
parallel, wherein, in those types of wrench, the internal op~n;ng both
extends through the entire head portion and is also laterally open on
one side.
By virtue of the turning force being transmitted in that way
primarily by way of the edge regions of the screw heads, part;c~ rly
when dealing with older screwswhich have a certain material softening
or fatigue effect, but also in the case of screws which are very
tightly fixed, there is the problem that the force to be ~pl;P~ may
exceed the strength of the edge regions so that the edges are
increasingly rounded off. That ro-n~;ng-off effect of the edges may be
to such an extent that the screw head generally becomes so greatly
rounded that it can no longer be displaced by the c~,.,~Lcially
av~ hle socket, open-end or ring wrench. It is then necessary to
carry out special working operations involving shearing off the screw
head or the like in order still to be able to slacken the screw. In
that case however the screw is generally desLL~yed and there is also
the serious risk of damaging the material which is clamped by the
screw. In this case also the screwthread can be removed from the screw
hole, only with considerable difficulties.
Those tools are also totally unsuitable for loosening round
connecting elements such as for example screw bolts or studs.
The object of the present invention is to provide a tool for
rotating rotatable connecting elements, which is distinguished by
affording improved utiIity value.
That object is attained by the features recited in claim 1.
Advantageous configurations of the invention are recited in the
append~nt claims.
- 216~052
The invention also provides advantageous effective methods of
reliably rotating and in part;clll~r loosening connecting elements with
r~und or polygonal or corrugated heads, as well as a connecting element
of a novel configuration which is ~spec;~lly effective in conjunction
with the tool according to the invention.
The tool according to the invention thus has at least one and
preferably at least two elements which is or are movable substantially
transversely to the center line of the internal opening and provided
with a pointed front surface. When the screw tool is used for loosening
a rotatable and preferably screwable connecting element, for example a
polygonal screw Il~lLel, the above-mentioned elements come into close
contact with the screw head so that the force is also transmitted
between the screw tool and the screw head by way of those additional
elements. That provides additional locations at which forces are
~rpl;e~ so that the mutual bracing effect between the screw tool and
the screw head of the polygonal screw Il~lLe~ is improved. In part;~ll~r
the fr~nt tip, which -tapers to a point, of the movable elements,
ensures that - when just a relatively small amount of force is ~rpl;e~
to the elements during the forward feed movement thereof - the movable
elements can dig into the material of the connecting element in an at
least partially punctiform manner with a pressure in relation to
surface area, which is very high as it acts in a punctiform manner, so
that, hetween the movable elements and the connecting element, this
configuration provides for a wedging action or a tooth-engagement
action in terms of the material used, which can be achieved with the
~pl;~tion of a small amount of force and which is nonetheless highly
effective, and that permits r~ hle loosening even of connecting
elements such as screw bolts which are firmly held in position and/or
which are completely round. In comparison, when using movable elements
with a flat front end surface, in pr;nc;ple it would not be possible to
achieve a material wedging action or tooth-~ng~ ent action as
referred to ah-ove.
` ; 21~!~052
._
If the enyay~~ t between the tips of the movable elements and
the screw head is at a location which is displaced relative to an
axially extending screw head edge, the points of engagement are on a
circle of ~m~ r radius than the normal force-LL~,~,~tting point of
engagement between the inside surfaces of the screw tool and the screw
head so that the risk of shearing off the screw head edges is
cnn~ rably reduced or screw heads which have already been rounded off
can still be loosened or tightened, with sufficient force.
Preferably there are two holes, in each of which there is
disposed a movable element with a tip at its front end, which holes are
disposed in mutually diametrally opposite relationship with respect to
the center line of the opening. By virtue of that arrangement the r~und
or polygonal head of the connecting element can be s~""~Llically
Cl~Tpe~ by the two movable elements so that the turning forces ~pl;e~
also act s~""~eLLically on the screw head and thus apply an optimum
turning force thereto. Upon tightening of the movable elements, that is
to say preferably the grub screws, the tips of the movable elements
penetrate with their conical tip configuration into the material of the
screw head so that this arrangement provides not only a force-locking
connection but also a positively locking connection which permits very
high turning forces to be transmitted to the screw head.
There is also the advant~geoll~ effect of an autcmatic
counteracting or locking action without additional means. More
specifically, when the two pointed elements which are in the form in
part;~-l~r of grub screws are tightened and thus press in punctiform
contact firmly against the screw head or penetrate slightly into same,
the tWD pointed elements each act as a locking means for the oppositely
po~e~ grub screw and press it against its own screwthread pitches so
greatly that - without the need for additional locking means - even
only slight rearward displacement of the grub screws when loosening the
screw ~ember is also reliably avoided. That means that the grub screws
automatically lock each other in position and permit the tr~n~m;~s;n~
of a high level of turning force.
2169!~52
_ 5
In addition, by virtue of the resulting effect of the connecting
element being clamped between the oppositely disposed tips of the
movable elements, it is poss-hl~ to prevent the connecting element
being pressed against the side surface of the op~n;ng in the tool. In
that case the transmission of turning force is produced exclusively by
way of the tips of the movable elements so that for example it is
poss'hle to avoid the risk of damage to or further rounding-off of the
side edges of the polygonal head of the connecting element.
m us, the tool according to the invention reduces the risk of
damage or deformation when tightening or loosening even softer, older
or firmly fixed screw members, and the tool can also reliably deal with
screw heads which are already deformed. The tool however is also highly
suitable for screwing on or screwing in elements, for ~XAmple screw
bolts, which are completely round from the point of view of their
design. It will be appreciated that nuts or the like can also be
loosened or tightened by the tool according to the invention. The tool
according to the invention is also suitable for screwing on or screwing
in screw members with heads having a round or corrugated outside
periphery such as for ~x~~ le screws with a h~x~nal recess therein,
with straight or corrugated inside surfaces (In~bus~-screws, Tor ~-
screws) or Tor ~-screws with a head having a corrugated outside
periphery.
In a preferred e~ho~-mPnt the holes which acc~mn~te the
elements are not only in the form of blind holes which are accessible
from the inside but they are in the form of holes which extend entirely
through the head portion so that the elements which are disposed in the
holes can also be actuated and possibly introduced from the outside.
That makes it easier to handle the tool according to the invention as
now for ~x~n~le the tool can firstly be fitted to the connecting
element, for example the screw head, in the usual way, and thereafter
the movable elements are brought into eng~g~mPnt with the screw head by
being actuated from the exterior. A11 holes and thus all movable
elemen~s are preferably disposed in a single plane which extends at a
216~052
right angle to the center line of the opening so that the axial length
of the tool can be kept small.
The movable elements may be of any configuration. In a preferred
~hoAim~nt however they involve screw pins or grub screws or set
screws, in which case the thr~ugh holes receiving the grub screws have
a corr~pnnAing internal screwthread. In that case, when they are not
in use, the grub screws are reliably held in the through hole and in
addition can be easily replaced in the event that they suffer from wear
or if necess~ry they can also be r~pl~ceA by a different grub screw
with a grub screw tip of a different profile. When the grub screw is
tightened after the tool has been fitted on to the screw head, it can
come into direct ~n~g~ment with the screw head and can apply
con~iA~rable forces thereto when the tool is turned, as the grub screw
is reliably prevented from moving back, by virtue of its screwthread
~n~T~nt.
Preferably the material of the movable elements affords a higher
level of tensile strength than the connecting elements to be loosened
so that the turning force can be transmitted by way of the elements,
without the risk of AAm~g;ng them.
In an alternative configuration it is also possihle to arrange
between the tip of the movable element, in particular the grub screw,
and the head of the screw member, a movable element disposed in the
interior of the head portion of the tool, for exdll~le a ball or
preferably a cone which is moved or biased forwardly in a direction
towards the screw head by the screw or another element which can
preferably be fixed in its respective position, and, when not in use
(or before the tool is fitted on to the screw head) can be moved back
into a retracted position in which it does not project into the
internal opening in the head portion of the tool. Alternatively, a
movable element for example in the form of a leaf spring which is
clamped at one end in the head portion, with a laterally projecting tip
or edge, may be provided between the grub screw or the adjusting
2l6sn~2
element which is of some other configuration, and the head of the
connecting element. In that case the leaf spring is so positioned in
its normal position that it terminates flush with the inside wall of
the internal opening in the tool. After the tool is fitted for ~x~mple
on to the screw member to be operated, the leaf spring can then be
biased towards the screw head by the adjusting element which is
disposed in the head portion, and in that case comes into firm
~ng~g~nent with the screw head so as to prcduce a bracing action
between the head portion of the tool and the screw head, which permits
a better tr~n~m;~sion of force than hitherto.
When using such an intermediate element, the center line of the
through hole does not necessary have to coinc;~e with the position in
respect of height of a screw head which is introduced into the screw
tool but, with respect to the front surface of the tool which is
towards the screw, the center line of the through hole may be set back
further rearwardly than the screw head extends inwardly.
In a preferred em~cdiment however the spacing between the center
line of the holes and the front surface of the head portion (the front
surface forms the insertion opPnlng for the screw head) is Rm~ r than
the axial thickness of the screw head of the screw which is to be
actuated by the tool. That provides that the movable element acts
directly axially on the screw head and it is thus poss;hle to achieve
optimum bracing thereto.
The holes are preferably so oriented that they intersect at a
right angle a flat inside wall surface of the internal opening of the
head portion. That means that the movable element moves at a right
angle towards the connecting element, for PX~rle the screw bolt or the
screw head, and can come effectively into engagement therewith. In that
respect it is preferred that the holes extend exactly at a right angle
to the center line of the internal opening in the head portion. That
arrangement ensures that the exit point of the holes lies directly on a
line bisecting a straight surface of the screw head to be actuated, and
2169n52
thus acts at a point on a circle with the smallest radius on the
outside of the screw head. When the screw tool is turned therefore the
tips of the movable elements effectively wedge th~m~lves in the
material of the screw head so that it is reliably possible and without
a major risk of damage to turn even rounded, round-h~A~e~, older and/or
very firmly fixed screw members.
As an alternative however it is also poss;hl e for the holes to
extend at a certain angle relative to the radius line of the head
portion so that the movable element acts inclinedly on the head of the
connecting element. That makes it possible to provide a preferential
direction in regard to the L~ ,~ssion of force, for ~.XAmrl e such
that, in a slackening operation, the movable element is brought into
firmer engagement with the surface of the screw head than in a screw-
tightening operation. In that case the holes are arranged ;ncl;ne~ly in
the head portion in such a way that, as viewed in the direction of the
movement of the head portion when loosening the screw member, the holes
are at a greater spacing relative to the radius line of the head
portion, at a radially further inwardly disposed position, than at a
radially further outwardly disposed position.
The number of holes in the head portion and thus also the movable
elements in the holes can be suitably selected. For ~XAmpl e, when
~eAl ;ng with relatively large screw heads, in addition to the two
diametral holes, it is possible to provide further holes having movable
elements, for e-x-ample one for each screw head side surface. For
~XAmrl e, there may be four holes with movable elements at angular
spAc;n~ of 90 in each case. It is also poss;hl~ to provide for
~xAmple three holes having movable elements which are disposed therein
or which are to be arranged therein, at equal mutual angular spacings
of 120.
The invention can be used with all kinds of screw tools for
actuating round or polygonal connecting elements, for ~xAm~le polygonal
screw members, for example in the case of inserts for socket wrenches
2169052
-
or in the case of the socket wrenches themselves, in parti~ll~r for box
wrenches, spark plug wrenches, wheel nut wrenches or n~çh;ne-operated
power wrenches. The tool may also be an insert ring for freewh~l
ratchets or a socket tool or a socket wrench insert. In general terms,
any hand-operated or m~hine-driven screw tool falls to be con~ red
as the tool according to the invention, for example incll~ing open-end
wrenches (jaw-type wrenches) or divided or undivided ring wrenches or
sp~nn~rs. Obviously - or even exclusively - the screw tool according to
the invention can also be used for slackening and/or tightening nuts,
screw pins or the like.
The configuration of the internal opening in the head portion may
be of a round or polygonal cross-section and has for ~x~mrle three,
four, six or twelve rectil;neArly ext~ing inside wall surfaces which
intersect each other at an angle, wherein the number of inside wall
surfaces can be adapted to the respective number of rectilin~rly
extending outside surfaces on the screw member to be actuated or can be
a multiple thereof, in most cases double same.
The tool according to the invention is distinguished by universal
utility. For example, it permits use both in connection with metric and
also inch size systems. By screwing in the movable elements fram
different and in particular oppositely disposed sides, into the tool,
until they came into ~ng~TPnt with the connecting element to be
turned by the tool, the difference in size between connecting elements
in accordance with the metric system and the inch system can be
campletely campensated. Therefore the user now no longer h-as to provide
separate specific tool sets for metric and inch systems, but with a
single tool, can deal with a respective multiple of different
connecting elements of different sizes or with different head shapes
(round, polygonal or corrugated cross-section).
Furthermore, by virtue of the tips of the movable elements
engaging with the connecting element to be operated on, the tool
affords a much better grip on the connecting element so that the risk
~l6sns2
of the tool lm~P~;rably sli~p;ng off the connecting element is
s;~n;f;cAntly reduced. That also s;gn;f;~Antly reduces the risk of
injury to the user.
The movable elements which are preferably in the form of grub
screws are preferably of a screwthread diameter of from about 3 to 4
mm. In the case of larger tools however it is of course also poss;hle
to use larger grub screws.
In accordance with the invention it is also possible for the
movable elements to be screwed into the tool to different extents, so
that the axis of the screw connecting element is displaced relative to
the center line of the tool opening. When the tool is rotated, it
UleLefore acts eccenLLically on the connecting element. It has been
found that, in that way, the forces which are transmitted by way of the
tips of the elements permit even more effective loosening of even very
firmly fixed screws, presumably by virtue of material being displaced
and piled up in front of the tips to diLLel~n~ degrees, in an initial
slight rotation of the tool relative to the connecting element.
If there should be little or no space for actuating the movable
elements at the location of use of the tool, it is also possible in
accordance with the invention that, before the tool is fitted on to the
connecting element to be loosened, the movable elements are screwed in
to such an extent that the mutual spacing between their tips is ~TAll~r
than the thickness of the head of the connecting element in that
region. Thereupon the tool can then be knocked on to the connecting
element, in which case the tips of the elements dig in a ~hAnnPl form
thr~ugh the peripheral surface of the connecting element. When the
screw tool is then turned, additional material poss; hl y builds up in
front of the tips of the elements and the tips of the elements which
have dug into the material entrain the connecting element so that the
latter is loosened.
The invention also provides a novel connecting element which has
at least one opening or hole into which the tip of the movable element
can pass when the tool is fitted. That makes it possible to provide a
2l6sn~2
ll
force-locking and positive-locking connection which can carry a high
lQ~;ng and which permits even very firmly fixed connecting elements to
be 1 o~s~n~d or which permits such connecting elements to be firmly
tightened, without the grub screws having to be dug deeply into the
material of the connecting element.
The invention is described in greater detail hereinafter by means
of a preferred ~mhQ~;mPnt with reference to the drawings in which:
Figure 1 shows an embodiment of the tool according to
the invention in the form of a socket wrench insert,
Figure 2 is a side view of the tool illus~ldLed in Figure 1, with
the plane of viewing turned through 90,
Figure 3 shows a front view of the ~mhc~;m~nt illustrated in
Figures 1 and 2,
Figure 4 is a sectional view of the tool illustrated in Figure 1
in section along section plane A-B illustrated in Figure 1,
Figure 5 shows an ~mhQ~;m~nt of the tool according to
the invention in the form of a ring and/or open-end wrench,
Figure 6 shows a partly broken-away view of the tool illustrated
in Figure 5,
Figures 7 and 8 show a mcdified ~m~o~ nt of the tool shown in
Figures 1 through 4 with a connecting element in the form of a screw
bolt, and
Figures 9 and 10 show an embodiment of a connecting element
according to the invention.
The e~bo~;~ent of the tool according to the invention, as shown
in Figures 1 through 4, is in the form of a socket wrench insert 1
having a head portion 2 and a drive portion 3. The head portion 2 is
provided with an internal opening 4 which, as can best be seen frcm
Figure 3, is in the shape of a h~xa~nn as viewed in cross-section. The
drive portion 3 in turn has a square opening 7 for ~n~ag~Tent with a
drive element (not shown), for ~x~mple a ratchet, a winch unit or an
extension. A transversely ext~n~;ng through bore 8 may be provided in
2l6sns2
12
the drive portion 3, which however does not possPss any function in
regard to rotational actuation of the socket wrench insert, but is only
intended to prevent the socket wrench from being axially pulled out of
the opPn;ng 7.
In accordance with the invention the socket wrench insert is
provided with two transversely extending through holes 5, 6 which have
an internal screwthread. As can be seen from Figure 3 the two through
holes 5, 6 are disposed in mutually diametrally opposite relationship
and extend at a right angle to the rect;l;nPAr inside wall surfaces of
the opening 4, their center line lying directly in the line bisecting
the rectilinear inside wall surfaces.
It will be seen from Figure 4 that the spacing between the front
surface of the socket wrench insert 1, by way of which a screw head 10
of a screw "~,~el 9 is guided into the internal opPn;ng 4, and the
center line of the through holes 5, 6, is smaller than the axial
thickness of the screw head 10. The through holes 5, 6 thus open
directly on to the recti-linear outside edges of the screw head 10.
As shown in Figure 4, screwed into each of the through holes 5, 6
are respective screw pins 11, 12 which are preferably in the form of
grub or set screws with front surfaces which taper to a point, with the
pointed tips of the grub screws lying concentrically on the center line
of the grub screws. Those preferably hardened grub screws thus press
with their pointed front surfaces centrally on to the outside surfaces
of the screw head 10 which has been introduced into the internal
opening 4. Preferably in that respect the screw pins 11, 12 are screwed
slightly outwardly by means of a screwdriver or the like, before the
screw head 10 is introduced into the opening 4, so that the insertion
opP~in~ is fully open and the screw head 10 can be introduced into the
internal opening 4 virtually without applying a force thereto. The
screw pins 11, 12 are then turned in such a way that they move
inwardly, more specifically to such an extent that their tip surfaces
bear directly against the outside surfaces of the screw head or press
- ` 21690S2
-
13
into same in punctiform f~h;on or by virtue of their conical tip
configuration. When the socket wrench insert 1 is then turned therefore
the turning force is transmitted to the screw head 10 not only by way
of the corner regions of the screw head and the internal opening 4, but
in particular also by way of the screw pins 11, 12, so that this
pr~vides an exLL~l~ly effective, force-locking connection. In that way
even screw members which are a very tight fit and which for ~X~T~le
have rusted in position, or screw members which are already r~unded
off, can be slackened (for example by striking the tool), without a
special tool being required. Also, when tightening a screw member,
coL~ n~;ngly increased screw forces can be ~L~I~tted to the screw
m~mber from the socket wrench without the risk of damage thereby.
In ~hc~i~ents which are not shown herein the tool may also be
formed by an insert ring for freewh~l ratchets, wherein the holes and
the movable elements disposed therein preferably pass not only through
the insert ring but also through the ext~rn~lly embracing ratchet ring
so that the movable ele~ents can be actuated from the exterior. Open-
end wrenches and ring wrenches or spanners may also be provided with
the through holes according to the invention and movable elements which
are acc~,~ ated therein, in part;~ll~r in the form of screw bodies,
wherein the relative arrangement between the thr~ugh holes and the
screw bcdies on the one hand and the head of the screw member to be
actuated on the other hand is preferably of the configuration shown in
Figure 4. It will be appreciated that in such a case the portions shown
in Figure 4 to the right of the end face of the screw head are omitted.
Figures 5 and 6 show an ~m~c~;~ent of the tool according to the
invention in the form of a wrench 13 which at its upper end is in the
form of a ring wrench and at its lower end in the form of an open-ended
wrench, However the wrench 13 may also be formed at both ends either
only as a ring wrench or only as an open-ended wrench, with different
wrench sizes.
21690~2
-
14
At its upper end the wrench 13 has an opening 14 in the form of a
ring, with twelve sides therein, which is designed to receive a
polygonal screw head of CO1L~L~OI~ ing size, but which can also be
pushed on to the head of a round connecting element. Provided in the
outside ring which surrounds the opening 14 are two through bores 5, 6
for receiving movable elements in the form of grub or set screws 11, 12
which extend at a right angle to the center line of the opening 14 and
which intersect the twelve-sided configuration of the opening in the
region of a projecting inside edge.
As can be seen fL~I the Figures, the grub screws 11, 12 which are
~LeLeL~bly made from hardened material are provided with front surfaces
which centrally converge to a point, and at their rearward ends they
have a recess with an internal h~xa~Qn. An I~bus wrench 15 (for
~ng~g;ng into a hexagonal recess)is used for actuating the grub screws.
Alternatively however the grub screw may also be provided with a
turning slot or the like, at its rear end.
At the lower end of the wrench 13 the opening 16 is of a jaw-like
configuration provided by two parallel jaws, wherein the holes 5, 6
extend in mutually directly oppositely ~;~pos~ relat;~h;p at a right
angle to the inside jaw surfaces and issue substantially centrally fm m
the internal jaw surfaces.
Figure 5 shows the grub screws 11, 12 in the condition in which
they have not yet been screwed into the wrench, while in the partly
broken-away view shown in Figure 6 the grub screws 11, 12 are screwed
into the holes 5, 6 in the tool 13.
As can be seen fm m all views, the grub screws 11, 12 are
preferably longer than the holes 5, 6 so that, even in the fully
screwed-in condition, they still project on the outside and are thus
r~A~ily accessible. It will be appreciated however that they can also
be shorter.
Figures 7 and 8 show a further embodiment of the tool in the form
of a socket wrench unit (socket wrench insert) 1' which, with the
exception of the round cross-section of the internal opening 4', is
2169052
_ 15
completely identical to the embcdiment shown in Figures 1 through 4.
The round cross-section of the opening can best be seen frcm the left-
hand front view in Figure 8. The socket wrench insert 1' is ~R; ~ne~
for actuating a round screw connecting element in the form for ~xA~rle
of a screw bolt 17, but it also makes it poss;hle to turn polygonal
screw heads, nuts and the like, which are introduced into the opening
4'.
The screw bolt 17 is of the usual round configuration with an
ext~r~lly screwthredded portion 18 and a round head portion 19 in
which there is provided an actuating portion 20 for ~x~rle in the form
of an internal hexagon. In the normal case, for unscrewing or screwing
up the screw bolt 17, the head portion 19 thereof is introduced into
the opening 4' and then the grub screws 11, 12 are screwed in to such
an extent that their tips dig into the surface of the head portion,
whereafter the tool 1' is turned by way of an exten~;on lever and/or
ratchet lever or the like.
Figures 9 and 10 show two different side views of an ~mho~;ment
of the rotatable or screwable connecting element according to
the invention, in the form of a screw bolt 21. In the same manner as
the screw bolt 17 shown in Figure 7, the screw bolt 21 is of a round
configuration with an externally screwthreaded portion 22 and a round
head portion 23 in which there is provided an actuating portion 24, for
~x~nple in the form of an internal ~x~on.
In addition the screw bolt 21 has two diametrally oppositely
disposed conical openings 25. The tips of the grub screws 11, 12 can
engage into the openings 25 in use of the tool according to
the invention, thereby pro~uc;~g a rotational connection which can
carry a high loading and which at the same time also prevents the
connecting element fL~Il unintent;on~lly f~ll;ng out of the tool. The
number and position of the openings 25 preferably depend on the number
and position of the movable elements in the tool. Instead of the
c~n;c~ openings 25 it is also poss;hle to provide op~ning~ of another
configuration, for Px~rrle through holes.
2l6~ns2
-
16
The connecting element according to the invention can also be
~;gn~d as a screw member, stud with a substantially cont;nuoll~
external screwthread, nut or the like, with op~n; n~ 25 which are
arranged in the outside periphery of the head and which are of a
5 c~n;c~l or other configuration.
