[0001] This invention relates to a lifting jack, and more specifically to its special construction
and operation employing electric drive, but with the facility for alternative manual
operation should the elec- . tricity supply fail.
[0002] In the automotive field, a manual operation of the jack for replacing a tire is particularly
slow, laborious and disagreeable, especially when atmospheric conditions are bad as
this operation has to be carried out in the open, and moreover in this emergency situation
the automobile user has to assume a physically abnormal operating position which is
particularly tiring after his immobility during driving, all this being further accentuated
in the case of female drivers.
[0003] GB-A-7038 discloses a lifting jack comprising a member for coupling to a vehicle
to be lifted, said coupling member being lifted by a threaded bar which is operationally
connected by way of a reduction unit to an electric motor; the reduction unit comprises
a first and a second shaft, the first shaft being connected to the motor and the second
being drivingly connected at one end to the threaded bar and being adapted at the
other end to receive a crank for manually operating the jack; said first shaft incorporates
an eccentric section, rotation of which is arranged to cause a displacement of said
first shaft away from the second shaft in order to release the engagement between
the at least one gear of each shaft and to define two alternative mutual positions
of the shafts, one being a position of withdrawal in which the respective gear is
disengaged for the purpose of manual operation of the jack.
[0004] As disclosed, however, this lifting jack has been proposed for raising locomotives
and other heavy objects, therefore, the reduction unit is not disposed in an arrangement
of minimum bulk since this is not necessary when using the lifting jack for raising
very big and heavy objects. The lifting jack of GB-A-7038, in fact, cannot be placed
in a luggage car having too big size.
[0005] DE-A-3109985 discloses a lifting jack of the type comprising a member for coupling
to the vehicle to be lifted from a base on which the jack also rests, said coupling
member being lifted by rotating a threaded bar, wherein the threaded bar is rotated
by a low voltage electric motor operationally connected to the bar by way of a reduction
unit constituted by two gears in cascade fixed on to parallel shafts, of which one
is connected to the motor and the other to the bar.
[0006] This lifting jack does not provide the purpose of manual operation and the reduction
unit and the motor are assembled in a housing of too big size as the motor is parallel
to the threaded bar.
[0007] The main object of the invention is to propose a lifting jack in which the various
components are disposed one above the other in an arrangement of minimum bulk when
not operating to the advantage of accessibility of the respective vehicle compartment.
[0008] These object and advantage together with others, which will be apparent from the
detailed description given hereinafter, are attained by a lifting jack comprising
a member for coupling to a vehicle to be lifted, said coupling member being lifted
by a threaded bar which is operationally connected by way of a reduction unit to an
electric motor; said reduction unit comprising a first and a second shaft, the first
shaft being connected to the motor and the second being drivingly connected at one
end to the threaded bar and being adapted at the other end to receive a crank for
manually operating the jack; said first shaft incorporating an eccentric section rotation
of which is arranged to cause a displacement of said first shaft away from the second
shaft in order to release the engagement between the at least one gear of each shaft
and to define two alternative mutual positions of the shafts, one being a position
of approach in which the respective gear is engaged for the purpose of electrical
operation of the jack, the other being a position of withdrawal in which the respective
gear is disengaged for the purpose of manual operation of the jack characterised in
that a first and a second set of gears are mounted in cascade on the first and the
second shafts respectively, the shafts are arranged parallel to each other, the axis
of the motor is arranged parallel to the shafts and the motor is a low voltage electric
motor for which the electrical supply is provided by the vehicle battery by way of
a cable adapted to be inserted into the vehicle cigarette lighter socket.
[0009] The invention is described hereinafter in the form of two different embodiments of
the jack to which the electrical operating device according to the invention is applied,
with reference to the accompanying drawings in which:
Figures 1 and 2 are side elevations of two types of jack both comprising the electrical
operating device according to the invention;
Figure 3 is an upper exploded view corresponding to the jack of Figure 1, but showing
in detail the components of the electrical operating device according to the invention;
Figure 4 is a side view of the jack of Figure 2, in its operating state;
Figure 5 is a partial view to an enlarged scale of the lower end of the jack of Figures
2 and 4 in its retracted state;
Figure 6 is a constructional assembly detail of the components of the upper part of
the jack of Figures 2, 4 and 5, in partial section on the line VI-VI of Figure 2.
[0010] In Figures 1 and 3, the reference numeral 1 indicates the threaded bar housed in
known manner in the box casing 2 which is welded lowerly at 3 to the base 4 for support
on the ground, and is provided laterally with a hollow support 5 in which at 6 there
is hinged the shank 7 which is swivelled when in operation into the angular engagement
position 7a for lifting the load but has its end housed in the plastic socket 8 (Figure
1) when not operating.
[0011] According to the new specific characteristic, to the top of the casing 2 there is
connected by known means a metal container 9 which is of approximately parallepipedal
geometry, is covered with a coating of plastic material (not shown) for aesthetic
and accident-prevention purposes, and contains a low voltage electric motor 10, for
which in the case of automobile application the supply can be the automobile battery,
provided by inserting the respective cable into the known cigarette lighter socket.
[0012] From said motor 10 there emerges through hole 101 the pinion 12, which has helical
teeth and thus operates with reduced noise and vibration (Figure 3).
[0013] With it there engages the gear 15 of the motion reduction unit, which is formed by
two sets of gears of normal cylindrical toothing 15,16,17,18 and 19, 20, 21, plus
a fourth gear, not shown, which engages in the gear 15 while the gears 16 and 19,
17 and 20, and 18 and 21 engage with each other.
[0014] The gears 15, 16,17,18 are carried by the shaft 13, while the gears 19, 20, 21 (plus
that not shown because hidden by the gear 19) are fixed on to the shaft 14. The shafts
13 and 14 are parallel.
[0015] All said gears are contained in cascade in the housing 22, which is constructed of
cast light alloy and is suitably closed by the cover 24, by means of the screws 23
which are screwed into the bored bosses 9a of the container 9 (Figure 3), thus also
retaining the housing itself.
[0016] On the inner end of the shaft 14 comprising the spline 14a there is fixed by means
of a known key the output bevel gear 25, which is directly coupled with the corresponding
orthogonal gear 26, fixed to the upper end of the threaded bar 1.
[0017] As shown in the figures, the shaft 14 emerges from the lower support boss 27 of the
cover 24, and the shaft 13 emerges through hole 100 from the upper boss 28.
[0018] According to a further characteristic of the invention, this latter shaft is provided
with an offset central diametrical sector 29 arranged to perform a specific function
described hereinafter, and its end 30 is provided with a facet 31 and a bore 32, for
housing and locking the inner end 32a of the lever 33 by means of the bolt 34 and
spacer 34a.
°
[0019] Said lever 33, constructed of special harmonic steel, is configured with a slightly
offset profile comprising a joining step 35, in order to allow it to operate with
a high level of elasticity, whereas the opposite end 36, i.e. the end outwards from
the aforesaid end, is fixed by a screw 37 and spacer 38 to the boss 39 which forms
one of the corresponding set of bosses which are positioned angularly spaced-apart
and comprise stiffening ribs 23a, their purpose being to fix the cover 24 to the corresponding
housing 22.
[0020] The jack operates as follows.
[0021] On pressing the rocker switch 11, the electric motor 10 is started and by way of
its pinion 12 rotates the set of reduction gears contained in the housing 22, and
of which the terminal bevel gear 26 drives the threaded bar 1 at low uniform speed,
to cause raising and subsequent lowering of the support and load lifting shank 7,
by two separate and opposite positionings of said switch 11.
[0022] Advantageously, said switch 11 is of open centre configuration, which operates only
while manual pressure is applied, i.e. on removal of pressure the electrical supply,
i.e. its operation, is interrupted, so that when the operator withdraws, the travel
movement of the jack immediately stops, with the obvious advantage of general accident
prevention.
[0023] The effective operability of the device with reference to its new components, its
validity, and its comfortable and safe handling are perfectly apparent.
[0024] A further useful aspect is that if for any reason the electrical supply to the motor
10 should fail, the jack is able to be set for conventional manual operation.
[0025] In such an emergency, the outer end 36 of the lever 33 is removed from the boss 39
of the cover 24 and is fixed to the other boss 40, in which case because of the eccentricity
of the sector 29 of the shaft 13, its gears 15,16,18 are no longer in direct engagement
with the corresponding gears of the shaft 14, i.e. this latter becomes radially displaced
from the shaft 13.
[0026] In such circumstances, the emergency angle crank 42 comprising a knurled operating
knob 43 is fitted on to the flattened end 41 of the shaft 14, to thus enable the operator
to proceed with the conventional method, even if only momentarily, thus allowing the
necessary tyre changing operation to be completed.
[0027] The aforegoing relates to the application of the electrical device according to the
invention to a conventional jack, but in which however certain difficulties often
arise, and in particular the excessive and non-uniform intensity of the mechanical
stresses, leading to variously directed forces which negatively affect the floor of
the vehicle, thus causing instability during lifting. A description will now be given
of a further application of the device according to the invention to a lifting device
which comprises a lever system, of which the operational linkage is able to align
the respective end loading points of those parts which make contact in operation,
along a trajectory coextensive with the respective curve followed as the vehicle is
tilted, with reference to Figures 2, 4, 5 and 6.
[0028] The jack according to the invention is essentially composed of a metal flanged support
51, comprising two spaced-apart lateral lugs 52 welded to it at 52a, and between which
is positioned the mobile support 53, provided with end projections 54 of continuous
profile.
[0029] The central sector 55 of the support 53 houses one end of the threaded bar 56 by
way of the thrust bearing 57, which bar, after passing through the housing 22 containing
the reduction gear 15-21 described heretofore with reference to Figure 3, emerges
by way of its flattened end 30 for connecting the crank 42 comprising the knurled
knob 43, for the purpose of any necessary emergency manual operation of the jack.
[0030] In contrast, in the embodiment of Figures 1 and 3, the shaft 14 comprises at its
exit from the reduction unit 22 a bevel gear 25. Within the said two lateral lugs
52 of the flange 51, and more specifically to the projections 54 of the mobile support
53 which emerge by way of their ends 58 in a torsionally rigid manner, there is welded
the box section of U cross-section 59, which is provided with an angular base 60 for
resting on the ground 61. In addition, in order to facilitate its mounting on said
mobile support 53, the box section 59 is provided in the upper part of its two side
flanges 62 with an end slot 63, which opens into the circular housing hole 64.
[0031] Again for the purposes of said assembly, the respective opposing two projections
54 of the mobile support 53 have reduced-diameter profiles with a semi-circular cross-section
65 which extends beyond the axis 66 passing through the centre of the circle, in order
to allow non-removable disengagement of the box section 59 during its operation described
hereinafter.
[0032] The lever 69 is hinged, In a manner which allows it to swivel, to the inside of the
flanges 62 of the box section 59, for example by means of the bolt 67 with locking
nut 68, and is configured as two parallel spaced-apart flat sections between which
there is positioned, by means of the bolt and nut 70, the ball joint 71 which comprises
an internal thread engaging with the end 72 of said bar 56.
[0033] The lever 69 is joined upperly by a weld 73 to the bracket 74, which is provided
on one side with a circular recess 75, and further provided with a pin 76 welded at
77 and retaining by way of the bore 79 the plate 78 which makes lifting contact with
the vehicle floor after being centered in the slot of the floor by means of the shank
80.
[0034] To extend the application of the jack to various types of automobile, the plate 78
for reasons of stability during lifting can also comprise a central appendix for housing
in the cavity 75, and be provided with a circular section piece arranged to rest on
the outside of the pin 76.
[0035] Again for universal application, the lever 69 instead of being as shown can be hinged
in a lower position by means of the further hole or other holes 81 provided in the
respective flanges 62 of the box section 59.
[0036] The jack device of Figures 2, 4,5 and 6 operates as follows. When a tire has to be
changed or other operations performed, the operator starts the electric motor 10 by
means of the known switch, to cause rotation of the threaded bar 56.
[0037] In this emergency situation, this latter rises to consequently swivel the lever 69
and press against the vehicle floor by way of the plate 78, so that with the box section
59 vertically positioned on the ground 61 by way of its base 60, the respective end
loading points A and B of the contacting lifting plate 78 and of the foot 60 resting
on the ground (Figure 4) become aligned along the trajectory C.
[0038] Said trajectory C remains coextensive with the curve D followed by the vehicle during
its lifting, thus leading to an advantageous gradual and uniform distribution of mechanical
stresses, the consequent short length of operational travel of the bar 56 obviating
any stumbling movement along the floor or counter-productive interference therewith.
[0039] As a further advantage, the components according to the invention, which are covered
by an aesthetic accident-prevention coating, become disposed one above the other in
an arrangement of minimum bulk when not operating, as shown in Figure 5, to the advantage
of accessibility of the respective vehicle compartment. Only two types of lifting
jack have been described and illustrated, however the electrical device according
to the invention can be applied with the same advantages to any other type of currently
commercially available jack.
1. A lifting jack comprising a member (7, 74) for coupling to a vehicle to be lifted,
said coupling member being lifted by a threaded bar (1, 56) which is operationally
connected by way of a reduction unit (15-18; 19-21) to an electric motor (10); said
reduction unit comprising a first (13) and a second (14) shaft, the first shaft (13)
being connected to the motor and the second (14) being drivingly connected at one
end to the threaded bar and being adapted at the other end to receive a crank (42)
for manually operating the jack; said first shaft (13) incorporating an eccentric
section (29), rotation of which is arranged to cause a displacement of said first
shaft (13) away from the second shaft (14) in order to release the engagement between
the at least one gear (15-18; 19-21) of each shaft and to define two alternative mutual
positions of the shafts, one being a position of approach in which the respective
gear is engaged for the purpose of electrical operation of the jack, the other being
a position of withdrawal in which the respective gear is disengaged for the purpose
of manual operation of the jack characterised in that a first (15-18) and a second
(19-21) set of gears are mounted in cascade on the first (13) and the second (14)
shafts respectively, the shafts are arranged parallel to each other, the axis of the
motor (10) is arranged parallel to the shafts and in the motor is a low voltage electric
motor for which the electrical supply is provided by the vehicle battery by way of
a cable adapted to be inserted into the vehicle cigarette lighter socket.
2. A jack as claimed in claim 1 in which the threaded bar (56) is screwed at one end
in a hinged manner to one end of a lever (69), the other end of which lever is hinged
to a section bar (59) which itself is hinged at its upper end to the reduction unit
(22) and rests on the ground at its lower end (60); the lever (69) comprising members
(74-78) for anchoring to the vehicle to be lifted following the rotation and consequent
swivel movement of said bar (59).
3. A jack as claimed in claim 2 characterized in that the threaded bar (56) is connected
to the reduction unit (22) by way of a thrust bearing (57) mounted in a mobile support
(53), in which said section bar (59) is hinged.
4. A jack as claimed in claim 2 characterized in that when the vehicle is lifted laterally,
the respective end loading points of the curved base (D) of the section bar (59) which
rests on the ground (B) and of the lifting members (A) are aligned along a changing
trajectory (C) coextensive with the curve which the vehicle to be lifted follows during
its lifting such that the lower loading points moves along the curved base section
(D) when the vehicle is being raised or lowered.
1. Ein Hebebock, versehen mit einem Passungselement (7, 74) für das zu hebende Fahrzeug,
dieses Passungselement wird mittels einer Gewindestange (1, 56), die operativ mittels
Untersetzungsgetriebe (15-18; 19-21) mit einem Elektromotor (10) verbunden ist, gehoben;
dieses Untersetzungsgetriebe besteht aus einer ersten Welle (13) und einer zweiten
Welle (14), wobei die erste Welle (13) dem Motor zugeschaltet ist und die zweite (14)
führenderweise an einem Wellenende mit der Gewindestange verbunden und an dem anderen
Wellenende derart ausgestattet ist, um einen Handgriff (42) zur manuellen Betätigung
des Hebebockes aufnehmen zu können; diese erste Welle (13) verfügt über einen Nockenabschnitt
(29), dessen Drehung eine Verschiebung der vorgenannten, ersten Welle (13) gegenüber
der zweiten Welle (14) auslöst, um die Kupplung zwischen zumindest einem Zahnradpaar
(15-18; 19-21) einer jeden Welle freizugeben, und um zwei wechselweise, gegenseitige
Positionen der Wellen zu bewirken, das heißt eine Anbewegungsposition, während der
das entsprechende Zahnradpaar gekuppelt ist, um den Hebebock elektrisch zu betätigen
und eine Rückbewegungsposition, während der das entsprechende Zahnradpaar entkuppelt
ist, um den Hebebock manuell zu betätigen, dadurch gekennzeichnet, daß eine erste
Zahnradreihe (15-18) und eine zweite Zahnradreihe (19-21) kaskadisch respektiv auf
der ersten Welle (13) und auf der zweiten Welle (14) montiert sind; die Wellen sind
gegenseitig parallel angeordnet, die Motorachse (10) ist den Wellen gegenüber parallel
angeordnet und der Motor ist ein Elektromotor mit Niederspannune, dessen Versorgung
durch die Batterie des Fahrzeuges mittels eines Kabels erfolgt, das in den Zigarettenanzünder
des Fahrzeuges eingesteckt wird.
2. Ein Hebebock, wie in Anspruch 1 geltend gemacht, wobei die Gewindestange (56) an
einem Ende klappbar auf einen Hebel (69) eingeschraubt ist, an dem anderen Ende ist
der Hebel klappbar auf ein Profil (59) aufmontiert, wobei auch dieses an seinem oberen
Ende klappbar an das Untersetzungsgetriebe (22) angeschlossen ist und mit seinem unteren
Teil (60) auf dem Boden aufliegt; der Hebel (69) verfügt über Elemente (74-78) zur
Verankerung an das zu hebende Fahrzeug; diese Elemente folgen der Drehung und der
folglichen, winkeligen Verschiebung des obengenannten Profils (59).
3. Ein Hebebock, wie in Anspruch 2 geltend gemacht, dadurch gekennzeichnet, daß die
Gewindestange (56) mittels auf ortsbeweglichem Halter (53), der klappbar in das obengenannte
Profil eingesetzt ist, montiertem Drucklager (57) mit dem Untersetzungsgetriebe (22)
verbunden ist.
4. Ein Hebebock, wie in Anspruch 2 geltend gemacht, dadurch gekennzeichnet, daß sich,
wenn das Fahrzeug seitlich angehoben wird, die entsprechenden Ladeendpunkte der gebogenen
Basis (D) des Profils (59), das auf dem Boden (B) aufliegt, und die Hubelemente (A)
fluchtgerecht längs einer veränderlichen Bahn befinden, koextensiv mit der Kurve,
der das Fahrzeug während des Hubs folgt, sodaß sich die unteren Ladepunkte längs des
Abschnittes der gebogenen Basis (D) bewegen, wenn das Fahrzeug angehoben oder abgesenkt
wird.
1. Un vérin, comportant un élément de couplage (7, 74) pour le véhicule à soulever,
le levage de l'élément de couplage susdit étant assuré à l'aide d'une barre filetée
(1, 56) qui, du point de vue opérationnel est connectée moyennant un réducteur (15-18;
19-21) à un moteur électrique (1'0); le réducteur comporte, à son tour, un premier
arbre (13) et un second arbre (14); le premier arbre (13) est connecté au moteur,
une extrémité du second arbre (14) est connectée à la barre filetée de sorte à opérer
comme élément d'entraînement, tandis que l'autre extrémité est conçue de sorte à pouvoir
recevoir une poignée (42), pour l'actionnement manuel du vérin; le premier arbre susdit
(13) présente une section excentrique (29) dont la rotation doit donner lieu au déplacement
du premier arbre susdit (13) par rapport au second arbre (14) afin de débloquer l'enclenchement
avec, au moins, un engrenage (15-18; 19-21) de chaque arbre et afin de créer deux
positions réciproques alternatives des arbres, notamment une position de rapprochement
où l'engrenage correspondant est enclenché pour assurer le fonctionnement électrique
du vérin et une position de recul où l'engrenage correspondant est débloqué pour consentir
l'actionnement manuel du vérin, caractérisé du fait que une première série d'engrenages
(15-18) et une seconde série d'engrenages (19-21) sont montées en cascade respectivement
sur le premier arbre (13) et sur le second arbre (14), les arbres sont disposés en
position parallèle l'un par rapport à l'autre, l'axe du moteur (10) est parallèle
aux arbres et le moteur est un moteur électrique bas voltage dont l'alimentation est
assurée à partir de la batterie du véhicule moyennant un câble expressément prévu
pour être inséré dans la prise de l'allume-cigares du véhicule.
2. Un vérin d'après la revendication 1 où la barre filetée (56) à une extrémité est
vissée - en charnière - à une partie terminale du levier (69) dont l'autre extrémité
est fixée de manière articulée à un élément profilé (59) également fixé à son extrémité
supérieure au réducteur (22), en manière articulée et dont la partie inférieure (60)
appuie au sol; le levier (69) est constitué d'éléments (74-78) d'ancrage au véhicule
à soulever qui suivent la rotation et le déplacement angulaire conséquent de l'élément
profilé susdit (59).
3. Un vérin d'après la revendication 2, caractérisé du fait que la barre filetée (56)
est connectée au réducteur (22) par l'intermédiaire d'un palier de butée (57), monté
dans un support mobile (53) où est fixé - en charnière- l'élément profilé susdit (59).
4. Un vérin d'après la revendication 2, caractérisé du fait que, lorsque le véhicule
est soulevé latéralement, les points terminaux de charge respectifs de la base recourbée
(D) de l'élément profilé (59) qui appuie au sol (B) et des éléments de levage (A)
s'alignent le long d'une trajectoire variable (C) suivant la courbe que le véhicule
à soulever suit pendant le levage, de sorte que les points inférieurs de charge se
déplacent le long de la section de la base recourbée (D), lorsqu'on soulève ou on
abaisse le véhicule.