Note: Descriptions are shown in the official language in which they were submitted.
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Background of the Invention
The present inve,~ltion relates to fastening devices
for rigidly fastening one member in an adjusted position
with respect to another, and it relates more particularly -
to means for locking such members rigidly together while
allowing adjustment of the position of one of the members
relative to the other prior to final tightening of the
fastener.
There are numerous situations in which two members
must be positioned relative to each other before they are
rigidly, and in some cases permanently, locked together ~y
means of a nut and bolt or similar ~astening device. For
example, in the construction of steel-frame buildings with
masonry facings, it is common practice to provide continuous
horizontal shelf angles at vertically spaced intervals up the
walls, so that the brick wall or other masonry i8 supported
by the steel frame-work. In such construction, erection of
the steel frame-work precedes the masonry, so that as the
ma~onr-- is brought up to the level of the shelf angle, it is
necessary to adjust the elevation of the shelf angle so that
its horizontal leg will fall within the mortar joint between
two courses of brick. Construction of the wall is then con-
tinued on top of the shelf angle. Additional ~helf angles are
- provided as required by good engineering practice.
Due to inherent tolerances in the manufacture of
~teel framing, as well as in masonry construction, and due also
to deflections that occur after the framework is erected, it
is practically impossible to preset the shelf angles at their
final locations until the wall is erected and structural
loads are actual~y applied. Consequently, it is
necessary to adjust the position of the shelf angle
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both vertically and horizontally with respect to a steel
beam, or other structural member, to which it is attached,
so that it is at the proper elevation relative to the brick
courses above and below it.
Horizontal adjustment of the shelf angle is readily
achieved simply by providing horizontal slots in one of
the members so that the bolts can slide in the slots as
the shelf angle is lined up with the brick wall. However,
the use of vertical slots has not been considered satisfactory
because of the necessity of locking the assembly against
slippage due to gravity loads by means of a high-tensile
bolt that requires the application of closely controlled
tightening torque for generating sufficient friction between
adjoining surfaces or by welding the assembly in its final
position. Both these techniques require the use of equipmen~,
as well as specialized labor, which often is not at the
site when the work is to be done. Furthermore, either
of these prior techniques is time consuming and requires
a high degree of quality control and inspection in order
to ensure the desired results. Consequently, the typical
installation relies on so-called ~finger shims" which are
slipped between the beam and the clips by which the shelf
angle is attached. The shelf angle is thus raised or lowered
by removing or inserting additional shims to achieve the
desired elevation.
The use of such shims is very costly and time
consuming due to the cost of the shims, the labor required
to fit up and install them initially and the labor req~ired
to make the necessary adjustments in order to line up the
shelf angle.
~ It is accordingly an object of the present invention
not only to provide a simpler way to moùnt shelf angles
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on steel beams, but also to facilitate fastening any member
rigidly to another while allowing for adjustment between such
members prior to final locking of the assembly. Another object
object of the invention is to provide means for positively lock-
ing such members together once they have been adjusted, so that
~ friction between them is not relied upon to prevent slippage.
j Summary of the Invention
Basically the invention resides in locking a tapered
segment, such as a threaded nut, bolt head or the like, in a
slot provided in one of two members to be joined. The walls
of the slot converge lengthwise in order to positively
block the movement of the segment in the direction in which
an external load is applied. When the fastener is tightened,
the tapered segment is forced into wedging engagement with
the walls of the slot, thereby positively preventing move-
ment toward the narrow end of the slot. Desirably the
segment is a nut having a longitudinal axis and sides which
taper at least in the direction of its axis. A bolt, or other
locking means by which the members are fastened together,
, 20 is held in a fixed position relative to the second member,
i so that as the bolt is tightened it draws the nut into
rigid wedging engagement within the slot in the first member.
It has been found that in certain applications, the walls of
the slot should also be beveled in a direction normal to the
plane of the slot so that full surface engagement may be
achieved between the working surfaces of the segment and the
walls of the slot without deforming the edge of the slot.
The invention resides in the fastening means as a
whole for wedging the tapered segment into the slot which
is tapered transversely of the taper of the segment, as well
as in the tapered segment itself and in the slotted member as
j individual components of the complete fastening system.
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Detailed Description of Preferred
Embodiment of the Invention
With the foregoing general information in mind,
reference is made to the accompanying drawings which illustrate
one embodiment of the invention as it may be employed in
bolting shelf angles to a structural member in a steel-
frame building. In the drawings,
Fig. 1 is a perspective view of a portion of a steel
frame for a building in which the fastening means of the
present invention may be employed in mounting shelf angles;
Fig. 2 is an enlarged exploded perspective view
of the fastening means shown in Fig. l;
Fig. 3 is an end view of the fastening means
of Figs. 1 and 2 as seen from the nut end of the assembly
with the nut and bolt disposed at one limit of adjustment
in the vertical slot;
Fig. 4 is a longitudinal section through the
locking bolt taken on the line 4-4 of Fig. 3;
Fig. 5 is a view similar to Fig. 3, but showing
the nut and bolt disposed at the opposite limit of adjustment,
and
~ig. 6 is a longitudinal section through the
locking bolt taken on the line 6-6 of Fiq. S.
In the specific application for the fastening means
of the present invention here illustrated, an I-beam 10 is
shown as a typical structural member in a steel-frame building,
the outer brick wall ~not shown) of which is built along
the far side of beam 10 parallel therewith. A continuous
shelf angle 12 is shown mounted on beam 10 using a plurality
of short clip angles 14, each of which in this instance
is bolted to the underside of the bottom flange of the
beam 10 by means of a pair of bolts 16. The brick wall
is normally built up until its top course reaches a level
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~ near shelf angle 12, which is then adjusted vertically
; and horizontally so that its horizontal leg is located
between the courses of brick immediately above and below
it.
Each clip angle 14 is provided in its horizontal
leg with a pair of elongated slots 18 through which bolts 16
extend so that the shelf angle 12 can be lined up horizontally
with the wall. Heretofore vertical adjustment between the
~- shelf angle and the beam has usually been accomplished
~ 10 by inserting shims of the required thickness between the
; horizon~al legs of the clip angles and the bottom leg of
the I-beam in order to take up any space between these
members before the bolts are tightened. It is of course
essential that this shimming be done with care in order
to ensure that the shelf angle is in contact with the brick
course below it. Accordingly, considerable time and tedious
efforts are required in shimming.
However, in accordance with the present invention,
.,
I shimming is eliminated entirely by providing each clip
; 20 angle 14 with a pair of uertically elongated slots 20, each of
which is tapered inwardly toward its lower end and by using
a nut 22 having sides or working surfaces 24 and 26 that taper
' both in the direction of the longitudinal axis of its threaded
; bore 28 and transversely thereof. A headed bolt 30 is
~ then threaded into each nut 22 through a hole 32 ~Fig. 2)
;~ drilled or punched in the shelf angle 12 80 that nut 22
is drawn against the converging side walls 34 of slot 20.
Nuts 22 therefore become rigidly wedged within the slot 20,
positively preventing downward movement of bolt 30 in the
s~ot. It will be apparent therefore that the only possible
slippage that can occur between the shelf angle 12 and
clips 14 is that resulting from actual deformation of the
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working surfaces 24 and 26 on nuts 22 or of the walls 34 of
slots 20. In contrast, if vertical slots were used with
conventional nuts and bolts, slippage can be prevented only
by the friction between the adjoining surfaces when the
vertical legs of the sheIf angle and clip are drawn together
by the bolts.
Tapered nuts 22 each have oppositely disposed
narrow and wide ends or faces betwe~en which the working
surfaces 24 and 26 extend, the distance between the working
surfaces at the narrow end being less than the space between
the walls 2I at the narrow end of slot 20, thereby permitting
the end of the nut 22 to be partially inserted into the slot
at the small end so that it can engage within the slot.
In using the fastening means of the present inven-
tion, the shelf-angle 12 will usually be pre-assembled on
the beam 10 in accordance with present practice. After the
beam is in place and during construction of the masonry
wall, the bolts 16 are loosened enough to permit the shelf
angle to be adjusted horizontally into alignment with the
wall, and then they are retightened. With the angle 12
adjusted horizontally bolts 30 are loosened, the shelf angle
brought up to its proper height, and the bolts retightened,
drawing the nuts 22 into wedging engagement with the walls
; 34 of the slots 20, thereby preventing displacement of the
shelf angle relative to the clip angle 14.
Where greater holding force is required to reduce
deformation of the walls of the slot in order to prevent
slippage of nuts 22, the side walls 34 of slots 20 should be
beveled as shown in Figs. 4 and 6 in a direction normal to
the slot at the same angle at which the sides 24 and 26 of
the nuts converge. The sides 24 and 26 of each nut will
then have surface contact with the side walls 34 of the
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slot instead of line contact therewith at the outer corner
of the slot, so that less deformation takes place under the
pressure of the weight of the wall on the shelf angle.
Referring in greater detail to Figs. 3 and 4, --.
it will be noted that nut 22 is trapezoidal in configuration
with :its sides 24 and 26 lying in planes which converge
both ~xially of the bolt 30 and tr~nsversely of lt. Thus,
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convergence of sides 24 and 26 axially of bolt 30 as shown
in Fig. 4 causes the nut 22 to wedge against the walls 34
of the slot as the nut is drawn axially into the slot by
bolt 30. In some applications the nut may be tapered only
along the longitudinal axis of the bolt, in which case the
working surfaces of the nut may be simply conically shaped
- or the oppositely disposed -~ide walls could converge only
in an axial direction. But convergence of the sides 24 and
26 and of the side walls 34 of slot 20 transversely of the
central axis of the bolt 30 as shown in Fig. 3, as well as
axially, provides greater assurance that the nut cannot be
shifted toward the small end of the slot.
It will also be noted that if the nut 22 is located
near the top or wider end of slot 20 when the shelf angle 12
is aligned vertically with the wall, it will be drawn deeper
- into the slot, as illustrated in Fig. 4 than if it is located
at the bottom or narrow end of the slot as shown in Figs. S
and 6. In this connection it will be apparent that within
the l~mit~ of adjustment allowed by slot 20, as represented
by the showing in Figs. 3 and 4, where the nut ?2 is located
at its uppermost position, and by the showing in Figs. S
and 6, where it is located at its lowest position, the
inner end 36 of nut 22 must not be drawn into engagement
with the near side 38 of the vertical leg of shelf angle 12.
If this were to happen, the nut 22 could not be drawn into
locking engagement with the side walls 34 of slot 20 without
recessing the surface of the shelf angle around the hole 32
to permit the end of the nut to project beyond the surface 40
of the clip angle. It is therefore important to coordinate
the slope of the sides 24 and 26 of the nut both axially
and transversely of the bolt 30 with the amount of vertical
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adjustment to be provided and with the depth of the slot 20.
It will likewise be noted that since the sides 24 and 26
of nut 22 must be in wedging engagement within slot 20
at every point along its length, the minimum width of the
inner end 36 of nut 22 must be less than the width of slot 20
at its narrow end. On the other hand, in order to prevent
the nut 22 from being drawn completely through slot 20, it
must of course be wider at its outer end than the slot 20
at its widest end.
Thus, since the tangent of the slope measured
tranQversely of the longitudinal axis of the bolt is propor-
tional to the amount of ad~ustment along the length of the
slot 20, and since the tangent of the slope measured axially
of the bolt is proportional to the depth to which the nut can
be inserted into the slot, the relationship of these four
variables may be expressed by the following equation:
tan a d
tan b h
where a is the slope of the working surfaces of the nut
measured transversely of the bolt,
b is the slope of the working surfaces of the nut
measured axially of the ~olt,
h is the vertical adjustment obtainable along the slot
and
d is the depth to which the nut must be allowed to
penetrate, which for practical purposes is the
minimum thickness of the material in which the
tapered slot is formed.
It will be apparent from this equation that the
slopes of the working surfaces 24 and 26 of the nut in
both direc~ions can be readily selected for any given thickness
d of the material in which the slot 20 is provided and
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a given maximum vertical adjustment h. Or given an existing
nut 22 with predetermined slopes of its working sides and
knowing the amount of vertical adjustment that may be
required, the thickness of the clip angle 14 can be easily
determined.
While the foregoing description of the preferred
embodiment of the invention refers specifically to one
application thereof, it is apparent that the invention can
be employed in many situations as, for example, in belt-
adjusting systems for power transmissions and the like.
Likewise, where the loads on the two members that are joined
are relatively light the tapered segment, which again may
take the form of a nut, may be conically shaped. Or the
tapered segment can be the head of a bolt and so shaped
that it fits within an eIongated slot in one of the members
being joined in the same way that the nut 22 is received
within the vertical slot 20. On the other hand, the segment -
may be a tapered insert similar to the nut 22 but having a
plain bore through which the bolt extends with a convention-
al nut threaded to the outer end of the bolt for forcing the
tapered segment into engagement with the walls of the slot.
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