Note: Descriptions are shown in the official language in which they were submitted.
, ' One type of vehicle suspension system which is
becoming increasingly popular is the MacPherSon strut
suspension system. The MacPherson s-tru-t is an integral coil
spring-shock absorber assembly which provides a li~htweight,
compact vehicle suspension system. The MacPherson strut
Isuspension system is disclosed in more detail in United States
Patent No. 2,624,592 to E.S. MacPherson.
One of the problems associated with the MacPherson
strut assembly is that the shock absorber unit -typically
~wears out before the associated coil spring. One solution -to
this problem is to manufacture the MacPherson strut assembly
with a construction which permits the shock absorber to be
readily remove~ and replaced with a new shock absorber.
How~ver, such a repair procedure can be rela-tively time
consuming, since typically the strut assembly must be removed
~from the vehicle.
I, One solution to reducing the time associa-ted wi-th
repairing a MacPherson s-trut assembly is disclosed in
United States Patent No. ~,03~,960 -to K.D. Kloster. The
Kloster patent discloses a pneumatic operated spring compressor
Iwhich can be utilized to repair a strut assembly while the
I lower por-tion of the assembly remains attached -to the
I vehicle. ~owever, the economics of such a compressor can
,~typically only be j~stified by repair shops which ~requently
¦,repair strut suspension systems.
Smaller repair shops typically utilize a relatively
~inexpensive spring compressor uni-t of the type manufactured
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from the spring.
The pair of shoes are preferably maintained in a
spaced apart relationship with the associated grooves in facing
relation to one another by means oE a threaded shank member
employed to effec-t movement of the spaced apar-t shoes toward
and away from one ano-ther during the operation of the tool.
Accordingly, it is an object of the presen-t invention
to provide a relatively economical spring compressor which can
effectively and safely be employed to compress a helical coil
spring.
~RIEF DESCRIPTION OF THE DRAWINGS
The invention will become more readily apparent to
one skilled in the art from reading the following detailed
description of a preferred embodiment of the invention when
considered in ligh-t of the accompanying drawings, in whicho
Figure 1 is a perspec-tive view of a spring compressor
embodying the features of the present invention;
Figure 2 is a rear elevational view of -the lower shoe
of the compressor of Figure l;
Figure 3 is a side elevational view of -the shoe shown
in Figure 2;
Figure 4 is a sec-tional view taken along line 4-4
of Figure 3;
Figure 5 is a top elevational view of -the shoe shown
in Figure 3;
Figure 6 is a sectional view taken along the line
6 6 of Figure 5; and
Figure 7 is an elevational view of a helical coil
spring having a pair of spring compressors according to the
present invention posi-tioned -thereon.
by Warren, Inc. of Jonesboro, Arkansas. This type of spring
includes a pair of spaced apart U-shaped hooks which are main-
tained in a facing rela-tion by means of an elongate bolt. In
operation, typically two or -three of the compressor units are
circumferentially spaced abou-t the coil spring and the bol-ts
are alternately -tightened to move the U-shaped hooks towards
one another, thereby compressing the spring. However, one of
the problems associated with -this type of spring compressor
is tha-t -the U-shaped hooks do not provide a good seating rela-
tionship with the helical coil of the spring which may lead
to twisting and misalignmen-t of the spring compressor. Such
twisting or misalignment may result in the dangerous condi-tion
of causing the compressor hooks to become dislodged `from the
spring and inflict injury upon the operator.
The present inven-tion provides an apparatus for com-
pressing a helical coil spring which comprises a pair of spaced
apart shoes each having a groove formed therein for receiving
a portion of the helical coil of the spring, at least one of
the shoes including a la-tchable locking means movable between
a retracted posi-tion wherein the portion of the helical coil
can be inserted into the groove and a locked pOsitiOIl wherein
the locking means extends over the groove for maintaining the
portion of the helical coil within the groove, means Eor moun-t-
ing the shoes in a spaced apart arrangemen-t wi-th the grooves
in facing relation to one another, and means for moving the
shoes toward and away from one another, -the means for moving
being adapted -to be disposed externally of -the coil spring -to
be compressed.
Even if the shoes become misaligned, the latchable
locking means prevents the apparatus from becoming dislodged
¦ I DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to Figure 1, there is shown a spring
compressor generally indicated ~y reference numeral 10
llembodying the features of ~he present inven~ion. The compressor
S 10-includes an upper shoe 12 and a lower shoe 14 which are
I maintained in a spaced apart relationship by an elongate
¦ threaded shank 16. The shoes 12 and 14 have helical grooves
17 and 18 formed therein for receiving a portion of the coil
ll~spring to be co~pressed. The shoes 12 and 14 also have
¦llatchable locking means 20 and 22, respectively, mounted
thereon which are extendible to a locked position across the
respective grooves to maintain the coil within khe groove
¦during the compression operation. The locking means can be
moved to a retracted position when it is desired to remove the
l~coil from the associated groove.
Referring to Figures 2 through 6, there are shown
more detailed drawings illustrating the features of the lower shoe
I unit 14. Except for an in-ternally threaded bushing 24 which i5
¦I centrally located within the shoe 14 to receive the one end
11 of the threaded shank 16, the shoe 14 is basically identical
to the upper 5hoe 12. Both shoes can be, for example,
aluminum castings.
As previously mentioned, the groove 18 is formed
l with a helical configuration. This type of construc-tion
1 provldes an increased bearing surface for engagement with the
coil of the spring, thereby militating against any twisting
of the shoe 14 during the compression of the spring. As
¦ shown in Figures 3 through 5, the groove 18 is defined by
~ arcuately forrned sidewalls 26 and 28 and a lower inclined
1I surface 30. As shown in Figure 4, the lower inclined surface
~30 is formed at an angle A with respect to a plane perpen-
dicular with the longitudinal axis of the threaded shank 16.
¦It has been found that an angle A of approximately 7 pro-
~ vides a medium angle which accommoda-tes most large helical
¦'springs. The sidewalls 26 and 28 of the groove 18 axe
arcuately formed and spaced apart sufficiently so as to
llencompass the expected size ranges of spri~gs. The groove
jl 17 of the upper shoe 12 is formed in a slmilar manner ~o the
Igroove 18.
lq I The latchable locking means 22 includes a U-shaped
Il member 32 formed from a s'teel rod and having a pair of parallel
¦l legs 34 and 36 which extend into parallel aper~ures 38 and 40t
1~ respectively, formed in the shoe 14, As shown in Figure 4,
1, the apertures 38 and 40 are formed at the same angle A as
ll the groove 18, The U-shaped member 32 is maintained in eithPr
Il a locked or retracted position by means of a pair of detent
~¦ assemblies 42 and 44 located in parallel apertures 46 and 48
¦ formed ln the shoe 14. The apertures 46 and 48 are perpendi-
Il, cular to an~ intersect the apertures 38 and 40, respectively,
Il As shown in Figure 6, the detent assembly 44
includes a ball 50, a spring 52, and a locking washer 54,
which are mounted within the aperture 48. Th~ spring 52
u.rges the ball 50 downwardly into either a locking detent 56
I or, a retracted detent 58 formed in the leg 36. The detent
¦ assembly 42 and the detents formed in the l.eg 34 are similar
to those associated with the leg 36. The latchable lockin~
means 20 of the upper shoe 12 is similar to the lockin~ ~eans 22.
When the U-shaped member 32 is pushed inwardly, as
s~own in Figure 5, the legs 34 and 36 will protrude from the
I apertures 38 and 40, respectively, and extend outwardly across
il -5-
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the top of the groove 18. At this time, the ball 50 will be
seated within the detent 56 to maintai.n the locking member
l32 in the locked position. The locking member 32 can be
¦moved to a retracted position, as illustrated in phantom in
~Figure 5, by pulling outwardly on the member 32 such that
the ball ~0 will be momentarily moved upward and then seat
within the detent 58.
.ll Figure 7 illustrates the general operational position
~of the spring compressing tool 10. Typically, at least two
jspring compressors 10 are utilized to compress a single coil
spring 60. In positioning the compressors 1~ on the spring
60, the locking means 20 and 22 are moved to the retracted
posi,tion while the end co~ils of the spring 50 are seated
¦Iwithin the grooves 17 and 18. Next, the locking means 20
~and 22 are moved to the locked position in order to secure
the shoes 12 and 14 to the coil. A suitable wrench can then be
~uti~ized to alternately rotate the bolts 16 to cause the lowex
and upper shoes to move toward one another~ thereby compressing
I the spring 60. As previously mentioned, the heli.cal grooves
11 17 and 18 tend to militate against any twisting of the com-
pressor 10 during the compression operation, while the locking
¦means 20 and 22 will prevent the compressor 10 from being
dislodged from the spring.
¦ In accordance with the provisions of the pa-tent
, statutes, the principle and mode of operation of the invention
have been explained in what is consiaered to represent
1 its best embodiment. It should, however, be unders-tood -that
¦ the invention may be practiced otherwise than as specifically
l il~ustrated and described without departing from its spirit
or scope.
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