[0001] This invention relates to a vehicle safety jack, of the type known as Y-jacks, with
a first support member that includes one end in the form of a foot in order to rest
the jack on the ground and the other end that receives a wharve, and another, second
support member with one end that pivots on the first support member and is finished
at its other end with a jaw or clamp in which the lower edge of the car body is received.
A threaded screw spindle passes through the wharve and the jaw and has a winding handle
connected to the end farthest from the wharve, so that when the winding handle is
turned in one direction, the second support member is raised with the jaw and the
vehicle, and when the winding handle is turned in the other direction, the second
support member or arm and the vehicle are lowered.
[0002] The jaw on the second support member is kept fixed against the free end of the screw
spindle, so that the screw spindle turns inside the wharve, thus moving the said wharve
and the said screw spindle towards or away from each other and causing the second
support member to be raised or lowered.
[0003] In order to keep the jaw fixed, the existence is known of a pipe or tube welded to
the screw spindle. The disadvantage of this solution is that it means an extra part
in the assemble, that increases the weight of the jack and also makes it more expensive,
since it requires a series of assembly operations to be carried out.
[0004] More recently, the solution is also known which consists of machining the interior
of the housing for the screw spindle in the jaw, thus providing an internal ledge
in the hole in the jaw, on which a rebate or recess in the screw spindle rests. The
free end of the screw spindle is connected by means of two washers and a central ball
bearing cage, which are secured to the said end by being riveted to it.
[0005] This solution is also complicated and costly, since it needs the corresponding machining
work to be carried out and also, when considerable stress is placed upon it, the screw
spindle rises on the stepped part in the interior of the jaw, with the corresponding
risks involved.
[0006] On the other hand, in jacks of this type, the support members or arms are usually
made up of parts with a U-shaped cross-section, so that when the jack is raised, the
end of the second support member, and more specifically the thickness of the end of
this second support member, impinges on and affects the rounded internal corners of
the first support member in such a way that, when considerably heavy loads have to
be raised, the end of the second support member buckle or twist at these said corners,
meaning that the jack is made unusable.
[0007] It is an object of this invention to provide a jack which has a simple jaw which
in itself is secured to the screw spindle without the need for any special machining
to be carried out.
[0008] Another object of this invention is to provide a jack with a sturdy or robust stop
for the support member that holds the screw spindle at its maximum elevation, so that
it preserves the integrity of the assembly and ensures the absence of buckled areas
when overloads exist.
[0009] In order to achieve these objectives, the invention claims a jaw, made of plastic,
which has a totally flat axial perforation in which the screw spindle is housed without
any kind of impediment. At the end of the jaw, on the side at the end of the screw
spindle, a housing is made of a greater diameter than the diameter of the hole for
the screw spindle, with this housing being connected on one side with the said hole
and on the other side with the exterior of the jaw through a hole.
[0010] The housing has two internal walls, one towards the screw spindle input and the other
towards its output. The screw spindle is housed freely in the jaw, as already pointed
out, and in the interior of the housing receives the ball bearing cage and the two
washers, which are controlled by the internal side walls of the said housing.
[0011] Through the hole at the outer end, the end of the screw spindle is riveted to the
outer of the two washers, thus securing the whole assembly irremovably. The screw
spindle remains free and completely unhindered inside the jaw and the jaw remains
perfectly controlled by means of the inclusion of the washers and the ball bearing
cage inside the housing in the jaw.
[0012] In order to achieve the second object of the invention, the invention claims the
realization of a set of lugs, one in each of the facing wings or sides of the first
support member of the jack, in a position that corresponds to that of the maximum
elevation of the second support member of the jack, usually close to the position
of the wharve in the first support member.
[0013] The two lugs are formed facing each other and as the result of windows or cut-outs
made in the said wings, protruding towards the interior of the support member, usually
perpendicular to the said wings.
[0014] In this way, when the edges of the second support member, in the position close to
that of maximum elevation, touch the base of the corners, they have come up against
the edges or thicknesses of the lugs. This meeting, edge against edge, offers sufficient
guarantees of resistence to allow the second support member to be completely protected,
even in spite of its being used to raise heavier loads than those for which it is
designed.
[0015] All these and other details of the invention are illustrated in the attached sheets
of drawings, in which a solution of the details claimed is represented for guidance
purposes only.
[0016] Figure 1 is an elevation of the jack that includes the invention.
[0017] Figure 2 is an external side elevation of the jaw in accordance with the invention.
[0018] Figure 3 is a longitudinal cross-sectional view of a conventional jaw with the screw
spindle assembled in its interior.
[0019] Figure 4 is a longitudinal cross-sectional view of the jaw with the screw spindle,
in accordance with the invention.
[0020] Figure 5 is a double cross-sectional view of the two support members or arms of the
jack, which illustrates, on the one hand, the problem that arises in the position
of maximum elevation and, on the other hand, the solution claimed by the invention.
[0021] Looking now at Figura 1, it is possible to appreciate a jack of the type known as
Y-jacks, provided with a first support member (1) with a support foot for resting
on the ground and which at its upper end receives the wharve (6) which has the threaded
screw spindle (3) passing through it. Seated on this first support member (1) is the
pivoting edge (10) of the second support member, whose other end includes the jaw
(5) which, in turn has the screw spindle (3) passing through it.
[0022] It is also possible to appreciate the housing (7) in the jaw (5) and its riveted
end (8), as well as the winding handle (4) for turning the screw spindle. We can also
observe the lug (9) cut into the wing or side of the first support member, and the
edge (10) of the second support member (2), close to the internal corners of the first
support member (1), which takes place when the said second support member (2) is at
its maximum elevation.
[0023] Referring now to Figure 2, the jaw (5) can be seen, with its end (11), into which
the screw spindle is inserted, and the forward housing (7).
[0024] Figure 3 shows the already known solution for making the jaw (12) irremovable. The
interior of this jaw has been machined, as shown, giving rise to the ledge (13) on
which the screw spindle (3) rests. The end of the screw spindle and the neck (17)
receive the two washers (14, 16) with the ball bearing cage (15) between them, which
are secured by the end of the screw spindle (8) being properly riveted.
[0025] The solution claimed by the invention, as best seen in Figure 4, shows how the screw
spindle passes through the straight continuous interior of the jaw (5), and in the
interior of the housing are situated the washers (14, 16) with the ball bearing cage
(15), controlled between the side walls of the said housing (7). Riveting of the end
(8) of the screw spindle is carried out through the outer hole, as illustrated, with
which the jaw (5) becomes perfectly irremovable.
[0026] Finally, the left part of Figure 5 shows the problem that arises in jacks when they
are subjected to overloading in the maximum elevation position of the second support
member, according to which the end edges of the support member (2) impinge on the
rounded corners (1) of the first support member (1), leading to their becoming strained
and permanently deformed, as at (20).
[0027] The right part represents the solution claimed in order to prevent this disadvantage,
and also illustrated in Figure 1. The lugs (9) in the wings or sides of the first
support member (1) are made, preferable from the support member itself, by the machining
that produces the windows or cut-outs (18). The lugs are established facing and aligned
with each other, as shown, so that their edges or thicknesses make contact with the
edges (10) of the support member (2), with sufficient strength at the meeting point
to be able to resist overloads.
[0028] It is important to emphasize, once having described the nature and advantages of
this invention, its non-restrictive character, inasmuch as changes in the shape, material
or dimensions of its constituent parts will not in any way alter its essence, as long
as they do not mean a substantial variation of the whole.
1.- Vehicle safety jack, of the type known as Y-jacks, with one support member (1) provided
at one end with a support foot and at the other end with a wharve (6) through which
a screw spindle (3) passes, and another support member (2) that pivots on the first
and includes a jaw or clamp (5) to receive the edge of the vehicle body, with the
screw spindle (3) also passing through this jaw, with a ball bearing cage (15) arranged
between two washers (14, 16) being situated between the jaw and the end of the screw
spindle, and one of these washers (14) being riveted to the said end (3) of the screw
spindle, which is characterized in that,
- the jaw (5) has a cylindrical continuous longitudinal internal cavity or recess,
crossed through by the screw spindle (3), with a housing (7) of a greater diameter
than the screw spindle at its outer end, with this housing receiving the washers (14,
16) that hold the ball bearing cage (15) between them, with these washers also having
the screw spindle passing through them and being controlled by the internal side walls
of the housing (7), in one direction or the other, and this housing also having an
open hole towards the free end (8) of the screw spindle into which the end of the
screw spindle enters and is riveted to the washer (14) situated in the position close
to the said end,
- two lugs cut into the wings of the U-shaped cross section of the support member
(1) provided with the foot, and both lugs being opposite and aligned with each other
in the interior of the said member, these lugs being made in a position close to the
wharve (6) and corresponding to the maximum elevation of the other support member
(2) of the jack, in such a way that the side edges of these lugs (9) make contact
with the edges of the jack member (2) in the maximum elevation position.
2.- Vehicle safety jack, in accordance with claim 1, characterized in that the facing
lugs (9) are essentially horizontal and are created in the wings of the support member
as a result of windows (18) cut into the said wings.
3.- Vehicle safety jack, in accordance with claim 1, characterized in that the jaw or
clamp (5), together with its housing (7), is, preferably, made of plastic.