Note: Descriptions are shown in the official language in which they were submitted.
Title: "Brake Band End Connection"
This invention relates to brake bands and refers
more particularly to a brake band end connection.
Background of the Invention
In the past, brake bands of the type pres~ntlY
contemplated have been in widespread use. One conventional
~rake band design incorporates forged brackets which are
butt-welded to the free ends of the band. The brackats
have required machining operations. Such bands have been
satisfactGry in use. However, they are relativel~ high in
cost and there has been a desire to produce a braXe band
which is effective in use but of lower cost.
One proposed construction is illustrated in U.S.
pat~nt No. 3,399,749. In this construction, stamped brackets
are welded on the outer surfaces adjacent the free ends of
the band. A lug is folded upwardly from the material o~ the
bracket. This lug forms abutment str~lcture for the actu~ting
struts.
Several problems have been encountered with such
structures. The upstanding nature o~ the lugs inherently
xesults in a bending force being applied to the lugs. This
ha~ resulted in failure of lugs during use G~ the band.
Additionally, the resulting lifting ~orce ha~ caus~d, in
some cases, separation of the bracket from th~ band a~ th~
weld points. Further, there has been excessive ~oe-in at
the ends of the bracket resulting in pr~mhtur~ arinq c~
the frictior, material provided on the working surface of
the band.
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In accordance with the present invention a brake
band structure is provided incorporating the desirable
cost-saving feature of welding brackets to the surface
of the free ends of the brake band while at the same time
providing a brake band which is as durable and effective
in use as previous forged constructions.
The brake band comprises a flexible, arcuate,
transversely split friction band element having a pair
of free ends normally spaced from one another. Means on
the band element are adapted to be engaged by actuating
means to contract the band element, said means including
a brac~et secured to the radially outer surface of the band
element adjacent one of the free ends thereof. The bracket
has a plate portion disposed in surface-to-surface contact
with the radially outer surface of the band element and
has an end adjacent said one free end of the band element.
~ The plate portion has a marginal edge projecting radially
; outwardly from the outer surface of the band element to
the outer surface of the plate portion, the marginal edge
extending transversely of the band element and facing away
from said one free end of the band element to provide an
abutment surface for the actuating means. The plate portion
has an integral tang bent up from the plate portion at a
point between the abutment surface and said end of said
. 25 plate portion. The tang has a locator portion extending
`" beyond the abutment surface to its free end in a direction
away from said end of the plate portion, said locator portion
being spaced from the outer surface of the band element a
~ distance equal to or greater than the radial extent of the
i~ 30 abutment surface. The locator portion and the outer surface
` of the band element serves to locate the actuating means when
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:-` in contact with the abutment surface.
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Brief Description of ihe Drawings
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Figure 1 is a plan view of a brake band in
accordance with one em~Gdiment of the present invention;
Figure 2 is a side elevational view of the band
of Figure 1 illustratively mounted on a drum with the
actuating struts in place;
Figure 3 is an enlarged view of the upper left
hand bracket of Figure 2; and
Figure 4 is a plan view of a modified bracket
construction.
Detailed Description
Referring to Figures 1-3, the brake band 10 com-
prises an annular band 12 and free ends 14,16. The band
normally flexes outwardly leaving a gap between the free
ends. The band 12 may be fabricated from conventional
carbon steels. A layer of friction material 18 is ad-
hered to the inner surface of the band 12. As will be
noted in Figure 2, the band is normally received on a cir-
cular drum 20. In operation, when the free ends 14,16 of
the band are forced towards each other, by means of struts
22,24, the brake material 18 engages the drum 20 causing
the drum to stop rotatin~.
A bracket 26,28 comprises essentially plate
portions which are secured to the outer surface or the
25 band 12 adjacent the free ends 14,16 as by welding at
30,32 so that the plate portions lie entirely on the band
12. One of the brackets 26 receives the apply strut 22.
This strut 22 is selectively actuated by means (not shown)
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to cause tightening of the band on the drum. The anchor
strut 24 is received on the other bracket 28. The anchor
strut 24 is fixedly mounted in structure (not shown).
Each of the brackets is provided with a recess 34,
36. The surface portions 38,40 define abutment surfaces
for line contact engagement with the rounded ends 42,4~
of the struts. As will be noted, the surface portions 38,
40 are transverse surfaces of the thickness of the plate
portions and are thus upstanding integral abutment surface
portions extending directly from the band 12 and transverse
thereof. Upstanding locator elements 46,48 are struck from
the material of each bracket and thus are physically sep-
arate from the abutment surface portions 38,40 and out of
alignment therewith. The function of these elements is to
guide these struts into contact with surfaces 38,40 and
to prevent escape of the struts radially outwardly from
the brackets when no force is applied to the struts.
As will be appreciated, particularly as viewed in
Figure 3, the end 42 of the strut 22 is in substantially
line contact with the discontinuous surface 38. This
results in the desired action of the applied force being
substantially tangential to the radius of the drum 20.
Further, as will be noted, the strut 22 lies against the
outer surface of the band 12 without intervening material
comprised of the thickness of the bracket. This results
in a reduced turning moment with respect to the drum sux-
face and thus reduces toe-in of the ends of the brake band
towards the drum surface. Reduced toe-in results in less
wear of the friction material. Also, as a consequence of
the strut 22 bearing directly against the discontinuous
surface 38, there is no bending moment attributable to the
bracket 26 which could further aggravate the toe-in prob-
lem.
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Operation of the bracket 28 and anchor strut is
substantially the same as above-described.
Figure 4 illustrates a modified form of the
brackets. In Figure 4, the bracket 50 i5 provided with
a recess 52 in which the abutting surface 54 is in the
center of the recess with the pair of locators 56,-58
being located adjacent thereto. As will be noted, the
abutment surface 54 is curved as opposed to the straight
surfaces previously described. Such a curved surface
1~ works in a manner comparable to a straight surface, the `~
exact configuration of this surface not appearing to
seriously affect operation of the bands.
