U.S. patent application number 09/855892 was filed with the patent office on 2002-03-14 for trolley for track systems.
This patent application is currently assigned to Wilfried Strothmann GmbH & Co. KG, Maschinenbau und Handhabungstechnik. Invention is credited to Heinze, Friedhelm, Massow, Rainer, Strothmann, Wilfried.
Application Number | 20020029717 09/855892 |
Document ID | / |
Family ID | 7642270 |
Filed Date | 2002-03-14 |
United States Patent
Application |
20020029717 |
Kind Code |
A1 |
Strothmann, Wilfried ; et
al. |
March 14, 2002 |
Trolley for track systems
Abstract
A trolley for track systems with essentially right-angled
intersections is equipped with raisable and lowerable rollers which
can be lowered to engage with, and raised to disengage with, one of
the pairs of tracks. A common actuator (76,78) simultaneously
lowers, in relation to the trolley, the rollers associated with one
pair of tracks and raises the rollers associated with the
intersecting pair of tracks.
Inventors: |
Strothmann, Wilfried;
(Schloss Holte-Stukenbrock, DE) ; Massow, Rainer;
(Schloss Holte-Stukenbrock, DE) ; Heinze, Friedhelm;
(Bielefeld, DE) |
Correspondence
Address: |
Richard M. Goldberg
Suite 419
25 East Salem Street
Hackensack
NJ
07601
US
|
Assignee: |
Wilfried Strothmann GmbH & Co.
KG, Maschinenbau und Handhabungstechnik
|
Family ID: |
7642270 |
Appl. No.: |
09/855892 |
Filed: |
May 15, 2001 |
Current U.S.
Class: |
104/106 ;
104/96 |
Current CPC
Class: |
B61J 1/10 20130101 |
Class at
Publication: |
104/106 ;
104/96 |
International
Class: |
E01B 025/22 |
Foreign Application Data
Date |
Code |
Application Number |
May 16, 2000 |
DE |
100 23 977.3 |
Claims
1. A trolley for track systems with essentially right-angled
intersections, with raisable and lowerable rollers on the trolleys
for alternatively engaging with one pair of the intersecting pairs
of tracks, characterized in that an actuator (76,86,88) is provided
for simultaneously raising, in relation to the trolley, the rollers
which engage with one pair of tracks, and lowering, in relation to
the trolley, the rollers which engage with the intersecting pair of
tracks.
2. The trolley of claim 2, characterized in that the rollers
(20,22,24,26,28,30,32,34) are mounted on trolley (10) by means of
suspension arms (52,54,58,60) in such a way that a horizontal
pushing or pulling force lifts or lowers the rollers in relation to
the trolley.
3. The trolley of claim 1 or 2, characterized in that for each pair
of tracks (12,14; 16,18) there are two rollers or roller groups (20
. . . 34) spaced at a distance.
4. The trolley of claim 3, characterized in that the central
actuator (76;86,88) drives two intersecting shafts (70,72) mounted
on trolley (10) and coupled via a bevel gear system (74), each of
said shafts extending between rollers or roller groups (20 . . .
34) for the individual tracks in the central portion of the four
sides of the trolley and bearing double levers (66,68) at their
ends which, when the shafts are rotated, exert a pulling force on
the rollers or roller groups for one of the pairs of tracks, and a
pushing force on the rollers or roller groups of the other pair of
tracks.
5. The trolley of claim 4, characterized in that the ends of double
levers (66,68) are each connected to a rod (62,64) whose other end
is connected to roller supports (36,38,40,42,44,46,48,50) of the
rollers or roller groups and exert a pulling or pushing force on
the latter when the shafts are rotated and the double levers
pivoted.
6. The trolley of claim 5, characterized in that the double levers
(66,68) on the ends of the shafts are arranged in relation to the
suspension arms (58,60) of the rollers or roller groups so that the
double levers (66,68) are positioned in the direction of rods
(62,64) when suspension arms (58,60) are directed downwards, whilst
the double levers are positioned vertical to rods (62,64) when
suspension arms (58,60) are pivoted out of the position in which
they are directed vertically downwards.
7. The trolley of one of the preceding claims, characterized in
that the actuator is a hydraulic cylinder (76).
8. The trolley of one of the preceding claims, characterized in
that two rollers at a time are mounted on a common roller support
(36; 50).
Description
[0001] This invention relates to a trolley for track systems with
essentially right-angled intersections, with raisable and lowerable
rollers on the trolley for alternatively engaging with one pair of
the intersecting pairs of tracks.
[0002] This invention is especially applicable to track systems
with tracks having a circular cross-section that are largely sunk
into the ground, as described in DE 43 18 383 CI. These types of
track systems can e.g. be laid in a works hall without creating any
major obstacle to walking or driving over the floor of the hall.
They also have a very high load-bearing capacity, making them
particularly suitable for transport work in industrial halls.
[0003] In order to make use of the entire surface area of the hall,
the tracks usually have to be laid in a grid with right-angled
intersections. The transition from one pair of tracks to another
pair of tracks intersecting at a right angle is achieved by raising
the rollers associated with the first pair of tracks, and
simultaneously lowering, in relation to the trolley, the rollers on
the trolley associated with the intersecting pair of tracks. This
ensures that only the rollers associated with the intersecting pair
of tracks engage with these latter tracks. Given that in certain
circumstances, the said changeover process has to be effected with
high or very high loads, it has proved difficult to create a
hard-wearing, durable changeover device that is nonetheless as
simple as possible and designed to ensure that the changeover
process can be carried out as quickly as possible.
[0004] The invention is therefore based on the task of creating a
trolley of the above-mentioned type with a changeover device for
the rollers which allows the rollers to be raised and lowered
virtually simultaneously and with relatively little application of
force.
[0005] According to the invention, this task is solved by a trolley
of the above type which is characterized in that an actuator is
provided for simultaneously raising, in relation to the trolley,
the rollers which engage with one pair of tracks and lowering, in
relation to the trolley, the rollers which engage with the
intersecting pair of tracks.
[0006] The changeover system according to the invention therefore
comprises only one actuator, e.g. a hydraulic cylinder, a spindle
drive or similar.
[0007] The trolleys of the type in question here are generally
equipped, in a quadratic arrangement overall, on all four sides and
in the vicinity of the ends of these sides, with rollers or roller
groups comprising two or three rollers.
[0008] According to the invention, these rollers or roller groups
are preferably mounted on the underside of the trolley by means of
suspension arms, and more specifically in such a way that a pulling
or pushing force in the direction along the side edges causes the
suspension arms to pivot, thereby raising or lowering the rollers
or roller groups. This means that the vertical adjustment of the
rollers or roller groups can be effected by exerting an appropriate
pushing or pulling force on the roller groups, e.g. from a position
in the middle of each of the side edges.
[0009] The central actuator preferably acts on two intersecting
shafts which are mounted on the trolley, are coupled via a bevel
gear system and each extend from side-middle to side-middle, i.e.
end up between the two rollers or roller groups on the four sides
of the contour of the trolley. Advantageously attached to these
ends there are double levers, each end of which is pivotably
connected to a rod which is pivotably connected by its other end to
a roller or roller group. By rotating the shafts and pivoting the
double levers correspondingly, a pulling or pushing force can be
exerted via the rods in the direction of the rollers or roller
groups. The pulling or pushing force lowers or raises the rollers
in relation to the trolley, the rollers being, as already
mentioned, pivotably mounted on the trolley by means of suspension
arms.
[0010] The suspension arms of the rollers or roller groups and the
double levers of the shafts are preferably arranged so that when
the rollers or roller groups are lowered, the suspension arns point
vertically downwards and the double levers assume a horizontal
position. In this way the suspension arms are subject to upwardly
directed push along their longitudinal direction and any deflected
lateral forces which might act on the suspension arms under heavy
loads are absorbed by the double levers in their longitudinal
direction. Both stress directions are extremely advantageous from
the kinematic point of view, and, in particular, prevent the drive
together with the shaft system from having to exert significant
holding torque in order to absorb the stress of the lowered
rollers.
[0011] There is another advantage to said arrangement of the
suspension arms and the double levers. This has to do with the fact
that the rods disposed between the double levers and the rollers or
roller groups are not displaced linearly, but execute circular
movements. Because of the said arrangement, the horizontal
component of the rods is relatively large at the beginning of the
lowering movement as the rollers or roller groups are lowered onto
the tracks, whilst the horizontal component then becomes smaller
and smaller as the double levers rotate. On the other hand, the
vertical component of the rollers or roller groups is also
relatively large at the beginning of the lowering movement of the
roller groups or rollers, whilst it decreases progressively towards
the end of the lowering movement. The result is that when the
rollers or roller groups are changed, the lowering movement of the
rollers for one of the pairs of tracks precedes the raising
movement of the rollers of the other pair of tracks. This means the
trolley is supported by the new rollers relatively quickly, so that
it loses virtually no height when the rollers are changed. Having
to lift the trolley up again after any loss of height would require
enormous force and an actuator of a corresponding size if the
trolley were heavily loaded.
[0012] Preferred examples of embodiments of the invention will be
explained in more detail below with reference to the drawings, in
which
[0013] FIG. 1 shows a diagrammatic top plan view onto a trolley
according to the invention, which is presented as transparent;
[0014] FIG. 2 is a view of the bottom of FIG. 1, also showing only
the outline of the trolley.
[0015] FIG. 3 shows a view of the left side of FIG. 1, using the
same type of presentation as for FIG. 2;
[0016] FIG. 4 is an isometric partial representation of the
actuator according to the invention;
[0017] FIG. 5 is a partial representation of the changeover
mechanism of another embodiment;
[0018] FIG. 6 illustrates a modification to FIG. 5.
[0019] In FIG. 1, an overall trolley is designated as 10. It forms
an essentially quadratic platform, but is only hinted at in its
outline in the drawing, as the details below refer solely to the
changeover rollers disposed underneath the trolley. Two
intersecting pairs of tracks are designated in the drawing by 12,14
and 16,18. In FIG. 1, the tracks are shown only as dash-dotted
lines. On each of tracks 12 and 14 as per FIG. 1 there are two
roller groups 20,22 and 24,26, each with two rollers which are not
designated separately. The pairs of rollers are disposed on the
individual sides at a distance from each other in the vicinity of
the comers of the trolley.
[0020] On the top and bottom sides as shown in FIG. 1 there are
corresponding tracks 16,18, on which are disposed pairs of rollers
28,30 and 32,34, which also comprise two rollers arranged one
behind the other, but not designated separately. The rollers of the
individual roller groups are mounted in roller supports 36,38,40,42
and 44,46,48,50. These roller supports 36 50 are suspended on both
sides with the help of suspension arms 52,54 (FIG. 4) from a rigid
construction part 56 of the trolley which is not shown in more
detail. The isometric view shown in FIG. 4 relates to the bottom
right comer of trolley 10 as per FIG. 1. Whilst the suspension arms
52,54 of roller support 42 of roller group 26 in the bottom right
of FIG. 4 adopt an inclined position, the corresponding suspension
arms 58,60 of roller group 32 shown on the left in FIG. 4 are
directed vertically downwards. This slight pivoting movement of the
suspension arms causes the roller group 32 shown on the left to lie
fixed on track 18, whilst roller group 26 on the right of FIG. 4 is
raised off track 14.
[0021] As is clearly shown in FIG. 4, the two roller supports 42
and 48 can be displaced horizontally by means of rods 62 and 64,
which are pivotably connected to the roller supports on the one
hand, and pivotably connected to one end of double levers 66,68 on
the other hand.
[0022] Double levers 66,68 are attached to the ends of shafts
70,72, which intersect in a bevel gear system 74 in the centre of
trolley 10 and divide the overall surface area of the trolley into
four equal squares. Shafts 70 and 72 are synchronously connected by
means of the bevel gear system.
[0023] The central actuator is a hydraulic cylinder 76, whose
piston rod 78 works together with the free end of a lever 80 which
is rigidly attached to shaft 70. The piston movement of hydraulic
cylinder 76 therefore simultaneously rotates both shaft 70 and, via
bevel gear system 74, the other shaft 72 as well. As the two double
levers 68 on the ends of shaft 72 are positioned vertically, and
the two double levers 66 on the ends of shaft 70 are positioned
horizontally, roller supports 44,46 and 48,50 are raised, and
roller supports 36,38,40,42 are lowered. Hydraulic cylinder 76 is
connected via two lines 82,84 with a two-way valve 86 which can
supply the oil flow from a hydraulic pump 88 to hydraulic cylinder
76 in both directions.
[0024] The invention is not limited in its application to tracks
with a round cross-section, or to grooved rollers as shown in the
drawings.
[0025] The trolley according to the invention is particularly
suited to being controlled from the floor of the works hall.
Rotatable positioning elements can, for example, be contrived in
the floor of the hall in the centres of the intersections, which
can engage with engaging elements on the underside of the trolleys
when a trolley is positioned above an intersection. In this way
roller groups 20,22,24,26 on two parallel sides of a trolley can be
lowered via the floor of the hall, and roller groups 28,30,32,34 on
the other two parallel edges of a trolley can be raised so that the
trolley changes direction by 90.degree..
[0026] FIGS. 5 and 6 illustrate diagrammatically how this can
happen.
[0027] Instead of the three intermeshing bevel wheels of the bevel
gear system 74 of the embodiment described above, one bevel wheel
90 is mounted on the underside of a trolley such that it can rotate
around a vertical axis. The underside of this bevel wheel 90 is
provided with an engaging element 92, which in turn is provided on
its underside with an engaging profile 94, e.g. in the form of a
screw slot. In the floor 96 of the hall there is a rotary actuator
98 which is able to rotate a positioning element 100, which can be
shaped e.g. like a screwdriver blade, by 90.degree.in both
directions.
[0028] The shape of engaging element 92 and positioning element 100
may be different, but should not pose an obstacle to walking or
driving over the floor of the hall in general. When a trolley is
driven over an intersection, positioning element 100 engages in the
slot of engaging profile 94. If rotary movement is then imparted to
rotary actuator 98, bevel wheel 90 can be rotated by 90.degree..
Engaging with the bevel wheel from four sides are bevel wheels
102,104,106, which are attached to shafts 70,72, which are
contrived here as split half-shafts in the two intersecting
directions. These bevel wheels 102,104,106 mesh with horizontal
bevel wheel 90. In contrast to the first embodiment they do not
engage with each other. They therefore rotate in the same
direction, and not in opposite directions, as in the first
embodiment. This needs to be taken into account in relation to the
arrangement of the subsequent control mechanisms.
[0029] It is therefore not necessary to equip each individual
trolley with its own transmitting and receiving system or such like
for the purpose of remote control inside a hall because the
trolleys are controlled by means of a positioning system laid in
the floor of the hall.
[0030] FIG. 6 also relates to the embodiment shown in FIG. 5, but
differs from the variant as per FIG. 5 in that instead of four
half-shafts, there is one continuous shaft 70 and two half-shafts
72 which transmit the rotation of bevel wheels 102,104,106 to the
changeover mechanisms as was the case in the first embodiment. In
both cases, the subsequent elements of the changeover mechanisms
have to be adapted to the direction of rotation of the bevel
wheels.
* * * * *