Note: Descriptions are shown in the official language in which they were submitted.
~2~;~3~L
The invention relates to a ~oint connection for girders
having more than two members connected in one joint, in
particular for steel structures, whose members are formed as
circular pipes, with the ends of the circular pipes con-
verging in a joint being attachable to one each joint element
by means of screw connections arranged in the axis of the
pipe.
Xnown joints of this type have the advantage that the members
transmit the traction and compression forces exclu~ively mathem-
atically precisely into the center of the joint connections. The
circular pipes functioning as members terminate on welded frustrums
with an a~ a~ial bore. A screw bolt supported on the frustrum
with its head inside of the pipe is screwable by means of a thread
provided on its front end into the bore of a joint element made
of solid material and projects outward through the bore. A pipe
or sleeve element penetrated by -the shaft of the screw bolt is
arranged between -the frustrum and the joint element. The slee~e
element is connected to the shaft o~ the bolt in such a manner
that the shaft can slide within the sleeve element, but no-t
rotate in relation to it.
The screw connection between the circular pipe and the joint
element can thus be made or released by turning the screw bolt
b~ means of the sleeve part.
Still, the joint connection described has many disadvantages.
It is elaborate due to the large number of metal parts to be
processed.The welding connection between circular pipe and
fruStrum is a weak spot and the strength of the circular pipes
can thus not be made ~ull use of. The high-strength screw bolts
themselves ara 3ubject to notch tension and thus do not create
a rigid, but ins-taad ~ sor-t of articulate connection between
the member3 and the joint element~, as their core cro~s sections
act a~ flow links in case of bending of the members. When measur-
_2
ing the members, the full buckling length up to the thread atthe front end of the screw bolts must be calculated. The inherent
rigidity of the girder is low r~he insertion of the screw bolts
necessitates assembling holes in the pipes which in turn call ~or
oppositely disposed drainage holes and thus locally weaken the
cross section of -the pipe. The inner walls of the pipes are un-
controllably subject to corrosion and pro-tection of the pipes
against the in-fluence of heat in the event of fire is hardly
possible. ~he fireproofness is thus not adequate, particularly
in the case OL halls in which many people congregate or airplanes
are kept.
It is the object of the inven-tion to provide a rigid joint
connection without weak-ening of the more than two members
connected in one joint which is free of the disadvantages
mentioned and requires a less elaborate produc-tion process. In
a joint connection of the type initially mentioned, the invention
resides in that -the ends of the circular pipes, without any
reduction of their cross section and flexural strength, are
provided with an external thread ~hose core diarneter is at least
equal to the outer diameter of the circular pipes, that a union
nu-t slidable or rotatable over the circular pipe is screwable
by means of its interior thread onto the external -thread and
that the union nut can moreover be screwed down on the joint
elernent. rrhiS creates a rigid connection between circular pipes
and joint element. I-t is also possible to fill the hollow spaces
communicatingly connected via the joint elements with a liquid
such as wa-ter, under addition of anticorrosives and optionally
antifreeze agents and to utilize the liquid for heating, cooling
and/or fire extinguishing in the event of fire 7 for the s-torage
of solar energy or the like.
L32~
In an advanta~eous embodiment of the joint connection
accordirg to the invention~ the union nut is screwable with
the front por-tion of its interior thread onto a corresponding
outer thread of the joint element. In the case of a liquid-
filled girder, it is possible to arrange a sealing ring which
optionally acts as a cross-section-reducing throttle (screen)
in the gap between the ends of the circular pipes and the
portion of the joint element provided with the external thread,
so as to influence the ~low thro-~gh the pipe system formed of
the circular pipes by means of this sealing ring.
In another, most favorable embodiment of the joint eonnection
according to the invention, the union nu-t is screwable by its
external -thread into a corresponding interior thread of the
joint element 9 the interior thread ar.d the exterior thread of
the union nut being of the same pi-tch and concentrically arrangedO
In this, the interior thread and the exterior thread of the
union nut are preferably arranged along its same longitudinal
portion, with the circular pipes connected to a joint projecting
into the joint element.
I-t is practical -to provide a union nut formed as a sleeve
with helically extending, undula-ting cross section. The union
nut formed as such a sleeve is advantageously provided on its
rear end with a ring projecting outward, which ring, - in the
case of a girder filled with liquid, - presses via an outer
sealing ring against the portion of -the joint element provided
with the interior thread and seals the interior -thread of the
union nut and the circular pipe via an inner sealing ring.
~.25~3~2~
The union nut with interior and exterior threads provided
along the same longitudinal portion can also be formed as a
spiral (helix); in the case of a liquid-filled girder, the
gap between the spiral windin~s can be filled with a sealing
mass in the zone in which the circular pipe projec-ts into the
joint element.
The union nut provided with the interior and exterior
thread along the same longitudinal por-lion can also be formed
as a sleeve with a spiral (helix) inserted or cast into it.
The spiral can be composed in cross section o~ two differently
profiled wire halves~
In the case of the liquid-filled girder, the joint elements
are hollow and formed with openings extending along the axes
of the adjacent circular pipes. It is practical to dimension
the diameter of the openings of the joint elements to be at
leas-t equal to the inner diameter of the circular pipes~ The
exterior thread can be formed onto the ends of the circular
pipes by plastic deformation such as pressing, upsetting and/
or rolling.
But the exterior thread can also be cut into the ends of -the
walls of -the circular pipes thickened by upsetting.
I-t is also possible to attach the exterior -thread to the
ends of the circular pipes by welding, such as build-up welding
or resistanoe pressure welding of a profiled wire spiral.
A girder provided with the joint connection according -to
the invention is advan-tageously filled with a liquid such as
water communicating via the joint elemen-ts and connected to a
liquid cycle.
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~25~3~
21950-1~
The joint elements and/or circular pipes can be
provided with valves which open, such as in case of fire, in
reac-tion to super pressure and/or excess temperature, whereby
the source of -fire or the girder can be sprayed with water
similar to a sprinkler systeM and the pipe walls can be cooled
by the flow thus created in the pipe.
Accordingly, the present invention provides a joint
connection for a girder assembly, the joint connection including
a joint element and a plurality of pipes which converge toward
and are connected to the joint element, the joint element being
provided with at least three exteriorly threaded portions
protruding therefrom in different directions, the exteriorly
threaded portions having exterior surfaces which are threaded.
Each of said pipes is a member which is circular in cross
sec-tion and has an unthreaded longitudinal section with threaded
end portions at its opposite ends, each said pipe having its
threaded end portions and its longitudinal section inseparably
~ormed together as a unitary structure, the threaded end
portions having exterior threads, the exterior -threads on each
~0 pipe having a core diameter which is no less than the exterior
diameter of the longitudinal section of the respec-tive pipe.
The threaded end portions of each pipe have cross sections which
are not reduced in size or strength rela-tive to the cross
section o-f the longi-tudinal section of the respective pipe, and
union nu-ts which have interior threads engaged with the exterior
threads of -the pipes. Each of the union nuts has a threaded
front portion which is screwed onto an exteriorly threaded
portion o~ the joint element, the union nuts being rotatable on
the exterior threads of said pipes and bearing against ~he joint
element.
6 --
~2~;~;3 2~
21950-14
The invention is explained in detail by means of
embodiments o~ joint connections accordin~ to the invention and
a girder composed thereof, under reference to the accompanying
drawings.
Figure 1 shows a girder in slant view from the top;
Figure 2 shows a detail of a joint connection, namely
a joint element in simplified representation;
Figures 3 to 6 show various e~bodiments of the ends of
circular pipes attached to the joint element according to Figure
2;
Figure 7 shows a joint connection in cross section;
Figure 8 shows another embodiment of a joint
connection also in cross section and
Figure 9 shows a detail of the joint connection
according to E'igure 8, namely a union nut, in an embodiment
different from that shown in Figure 8.
Figure 1 shows a girder in the form of a typical two-
layered spatial trussed structure consisting of joint elements 1
and members formed of circular pipes 2, in simplified
representationO The ~oint elements 1 and circular pipes 2 form
a communicating liquid system with their hollow spaces. The
liquid system is connected to a liquid cycle via inlet lines 3
arranged on the corners of the spatial trussed structure and
recirculating lines 4 disposed in the center of the spatial
trussed structure. A liquid container 5, a branch-off valve 6
and a pump 7 are provided in the liquid cycle.
- ~a -
3~
A heat exchanger 8 serving as a heater, cooler or for the
recovery o~ solar energy can be fed Yia a bypass line l~ading
from the branch-off val~e 6 to the pump 7. I~ the heat exchanger
is used as a heater9 the pump 7 can be operated via a heat
control, in the event of fire, it can be operated via a fire
alarm device or by means of a float-type switch, in the event of
loss of liquid~ by opening of one of the temperature- and pressure-
dependent valves in -the network. Losse5 in the liquid system can
be replaced from the local water line via an automatic valve 9
controlled by the level of the liquid container 5. The liquid
used can be water with additions of anticorrosives and anti-
freeze agents.
Fig. 2 shows one of the joint elements bearing the reference
number 1 in Fig. 1. Each one of the Fig. 3 to 6 shows an end of
a circular pipe 2 provided with an exterior thread 13 and connected
to the joint element. The exterior thread 10 in Fig. 3 is formed
by pressing, the exterior thread in Fig. 4 is formed by upsetting
and rolling or by cutting into the upse-t end of the pipe. The
exterior thread 10 shown in Fig. 5 is formed by build-up welding
on the end of the pipe 2. According to Fig. 6, the exterior
thread 10 i5 welded onto the end of the circular pipe 2 in the
form of a spiral (helix) of profiled wire~ for instance by means
or resistance pr0ssure welding. In all cases, the core diameter
d1 of the exterior thread 10 is at leas-t equal to the outer
diameter D of the circular pipe 2, the cross section of the pipe
remains unreduced.
Fig~ 7 shows a joint connection in cross section at enlarged
scale. ~his figure shows how the end of a circular pipe 2
provided with an exterior thread 10 is attached to the joint
element 1; a union nut 11 slidable or screwable over the
~,5~3f~
cicular pipe 2 is screwed by means of its interior thread
12 onto the exterior thread 10. The union nut is simult~neously
screwed with the front portion of its interior thread 12
onto a corresponding exterior thread 13 of the joint elem0nt
1. A sealing ring 14 is provided in the gap between the ends
of the circular pipe 2 and the portion of the joint element
1 provided with the exterior thread 13. One of the sealing
rings 14 shown in Fig. 7 is formed as a cross-section-reducing
throttle for influencing the flow in the system. I`he reference
number 15 indicates a valve attached to the joint element l
this valve can serve for ventilation or as a superpressure
or excess temperature valve and is represented in de-tail in
Fig. 8.
Fig. 8, also in enlarged scale, shows another embodiment
of the joint connection according to -the invention9 with two
different types of union nuts 16 and 17. In both cases, the
union nut 16 or 17 is screwed by means of an exterior thread
18 or 19 provided on it into a corresponding interior thread
20 or 21 of the joint element 1. The interior thread bearing
the reference numbers 22 and 23 in this case and the exterior
thread lo and 19 of the union nut 16 and 17 are arranged with
the same pitch, concentrically and along the same longitudinal
portion of it. A particularly strong connection is achieved
by the fact that -the circular pipes 2 connected to a join-t
projec-t into the joint element 1.
The union nut 16 shown in Fig. 8 is formed as a sleeve
with a helically extending, undula-ting cross section. It is
provided on its rear end with a ring 24 projectint outward.
The ring 24 presses against the end of the portion of -the
joint element 1 provided with -the interior thread 20 via an
outer sealing ring 25. Moreover, an inner sealing ring 26
seals -the i~erior-----~------------------_-_-_-___________
thread 22 and -the circular pipe 2.
The union rlu-t 17 sho~n in ~ig. 8 is formed as a spiral
(helix). After screwing the union nut 17 formed as a spiral
into the gap between the interior thread 21 of the joint
element 1 and the exterior thread 10 of-the circular pipe 2
the gap between the spiral windings of the union nut 17 ~as
filled by injecting a sealing mass 26.
Fig. 9 shows a further embodiment of a union nut 27~ formed
as a sleeve with a spiral (helix) 28 inserted in it. The spiral
28 can be composed of two differently profiled wire halves in
cross section.
In the joint connections according to Fig. 7 and 89 the
joint elements 1 are hollow and provided with openings 30
extending along the axes of the adjacent circular pipes 2. The
diameter of the openings 30 is at least equal to the inner
diameter d of the circular pipes 2.
~ ig. 8 further shows a valve 15 adjacen-t circular pipe 2. A
valve pipe 31 in which a valve body 33 loaded by means of a
pressure spring 32 is disposed is screwed into the circular
pipe 2. ~he pressure spring 32 presses on the other end onto
a platelet 34 of fusible solder which makes way for pressure
spring 32 and valve body 33 at correspondingly high temperatures
so -that the water can flow out on top of -the valve pie 31. The
valve pipe 31 is further provided wi-th lateral orifices 35
through which the wa-ter can flow no-t only in case of the melting
of the pla-telet 34, but also in the event that the pressure in
the fluid sys-tem reaches so high a value tha-t forces the valve
body upward to the orifices 35 against the force of the pressure
spring 32. A cross-sec-tion-reducing throttle (screen) is inserted
in the circular pipe 2 and bears the reference number 36~ in this
embodiment, it replaces the sealing ring 14 acting as a thro-ttle
shown in Fig. 7.
_g_
3~
~ he joint connection according to the invention is suitable
for ~irder~ of all types, in pPrticular ~or three~dimensional
girders9 multiple chord truss girders, truss plateR, barrels
and folded plates9 one-layered and multipl~-layered truss
cupolas, girder cupolas, steel deckings and plane load-bearing
structures.
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