GB2051004A - Car parking apparatus - Google Patents

Abstract

The invention relates to car parking apparatus of the type including a frame carrying a platform for a car which can be raised to enable another car to be parked underneath. Such apparatus has been proposed in which the platform can be raised and lowered while maintaining a substantially horizontal orientation. While it has been quite satisfactory it has been difficult to ensure smooth operation and there is a need for such apparatus which will perform smoothly and reliably with the complete safety that is required. According to the present invention the platform (2) is raised and lowered on a pair of two stage piston cylinder mechanisms (32) adjacent upright frame members (10) on either side of the platform. Preferably the platform (2) is supported on a carriage (4) which itself has upstanding members parallel to the frame members (10). The horizontal orientation of the platform (2) is maintained in the preferred embodiment by vertically spaced rollers on the upstanding carriage members running in tracks in the frame members. <IMAGE>

Description

SPECIFICATION Improvements in car-parking apparatus This invention relates to car parking apparatus of the type including a frame carrying a platform on which a car may be positioned, the platform being capable of being raised so that another car can be parked beneath the platform.

Such apparatus is advantageous due to the fact that a considerable saving of space can be achieved by having cars parked on raised platforms as well as on the ground. In a known form of apparatus, the platform is pivotally mounted at one end so that the other end may be lowered to the ground and a car driven up onto the platform. The lowered end is then raised by pivoting the platform upwardly into a storing position. A disadvantage arising from this arrangement is that the platform, in its lowered position, extends at a rather steep upward angle, and users are loathe to drive their cars at such an inclination in a confined space.

In our patent application No. 30309/77, there is disclosed car parking apparatus which comprises a frame, a platform on to which a car may be driven, means for raising and lowering the platform with respect to the frame while maintaining the platform in a generally horizontal condition, locking means for locking the platform on the frame at a height at which another car can be parked in the space underneath the platform, and a device for detecting the presence of a car when so parked and preventing lowering of the platform if an attempt is made to unlock and lower the platform when a car is so parked.

The locking means may take the form of a movable member or members, e.g. latches on either of the platform and frame, and arranged to co-operate with a fixed abutment or abutments on the frame or platform respectively when the platform is in a raised position to prevent the platform from being lowered.

The detecting means is preferably a swinging arm which is interconnected with a release means which is operable to unlock the platform, the arrangement being such that the operation of the release means causes the arm to move into the space beneath the platform so that if the arm engages an object in this space further operation of the release means fully to unlock the platform is prevented.

The platform may be raised or lowered by hydraulic piston and cylinder arrangements, switches desirably being provided automatically to turn off the supply of fluid to the cylinders when the platform is in its fully raised or lowered position.

This apparatus works very well and is reliable and safe. Nevertheless, all car parking machines suffer from a customer acceptance problem, car owners being very sensitive to any risk of their vehicles being damaged, and so even an absolutely safe and reliable parking machine is likely to find few car park operators who will install it unless when it operates it looks completely safe and secure, lifting and lowering smoothly with no jerks or vibrations and no undesirable deflections ofthe frame or platform.

However, complete smoothness and stability in operation is difficult to achieve without making the structure unacceptably massive.

It is an object of the invention to provide a parking machine of the general kind disclosed in our prior application but which is more stable in operation and requires less headroom in underground installations.

A further object is to simplifiy emergency operation of the machine in the event of a power failure.

According to the present invention, car parking apparatus of the kind described is equipped with two telescopic two-stage piston-and-cylinder units, one at either side of the frame, for raising and lowering the platform, these units being disposed substantially vertically alongside frame uprights with the cylinders lowermost and mounted at their lower ends on side members at the base of the frame. The lifting load is therefore transmitted directly to the base of the frame substantially at ground level where the resistance to deflection or vibration is greatest.

According to another aspect of the invention, the power drive for the apparatus is provided by a power pack comprising a mains supplied electric motor driving a hydraulic pump. A mechanical system can be included to enable the apparatus usable in the event of a mains power failure, particularly to release a car parked on the raised platform.

In preferred embodiments of the invention, the platform is carried on a carriage having vertical upstanding members generally parallel to the upright frame members, the piston/cylinder mechanisms being connected between the frame and the upstanding carriage members. The adjacent members can thus provide means for preserving the horizontal orientation of the platform by a slide and track arrangement, preferably using rollers on the carriage running in tracks in the frame members. Even in this preferred arrangement slider plants are used to limit or even prevent lateral tilting of the platform.

Stability can be further ensured by an arm extending diagonally from an end of the platform to the platform support, and/or by a pivoting frame assembly comprising an anti-roll bar extending longitudinally, either forwardly or rearwardly to the free ends of arms pivotally mounted on the frame.

An embodiment of the invention will now be described by way of example and with reference to the accompanying schematic drawings wherein: Figure 1 is a side elevation of apparatus according to the invention; Figure 2 is an end view showing the upright frame and carriage members; Figure 3 is a detailed view of the roller assembly between the upright carriage and frame members; and Figure 4 is a plan section taken on line IV-IV of Figure 3.

The apparatus includes a frame on which a platform 2 is fixidly mounted on a carriage 4for recip rocal vertical motion. The carriage 4 is provided with vertically extending members 6, located intermediate the ends of the platform 2, with one member on each side. Each member 6 has rollers 8 mounted thereon which ride in a track on the inner side of one of a pair vertical members 10 of the frame. The rollers on each member 6 are vertically spaced so that pivoting of the carriage about a horizontal axis relative to the members 10 is prevented during raising and lowering of the carriage 4. To further enhance the rigidity and stability of the platform 2 and carriage 4, arms 12 extend from the members 6 to the front end of the platform 2. Additional arms (not shown) may extend rearwardly if needed.As shown, the members 10 each include an inclined portion 14 at its upper end which the respective track extends into. As the upper roller runs into this portion 14 as the carriage 4 is raised, the platform is tilted slightly forwards to provide additional security for a car parked thereon by reducing the risk of the car running backwards off the platform 2. Alternatively, the platform 2 may have a permanent forward incline, enabling the inclined portion 14to be foregone (straightened).

The design of the rollers and tracks is important to ensure smooth and stable movement of the carriage 4. More particularly, a lateral clearance between a roller and track is desirable to prevent locking of a roller which can cause the platform to tilt about its longitudinal axis. The stabilizer arrangement described below is one way to preserve lateral stability and another is the provision of slider plates between the vertical carriage members 6 and frame members 10.The roller and slider track plate assembly is shown schematically in Figures 3 and 4. Each roller 8 is mounted on a spindle 16 fixed to the carriage members 6 and runs in an enclosed track 18.

Attached to each carriage member 6 is a slider plate 20 having a slide surface 22, typically of TEFLON (registered Trade Mark). A corresponding slide surface is provided on the frame members 10. The slide surfaces need not be in continuous engagement, but close spacing can ensure that lateral tilt is minimized and certainly kept below a level at which the rollers 8 will lock.

Another feature that may be incorporated to inhibit roller locking is the provision of a degree of freedom in the mounting of the roller 8 on the spindle 16. This may be done by mounting the roller 8 on the spindle 16 via a semi-spherical bearing (not shown). The degree of freedom is preferably limited to 1 to 2 degrees. The rollers are made in a very hard material and are preferably profiled to avoid undesired wear on the tracks. Typically, the rollers are or hard rubber or a steel backed rigid plastics material.

The apparatus described is further stabilized by a pivoting frame arrangement forward of the frame members 10. An anti-roll bar 24 traverses the platform 2 and extends forwardly from each carriage member 6 laterally outside and beyond the end of the platform 2 to the free end of an arm 26. The other end of the arm 26 is pivotally mounted on the frame at 28. The two arms 26 may be connected, either between the free ends or along their length to prevent distortion. The bar 24 is preferably webbed in its longitudinal portions to improve the stiffness. The pivotal connections have a very close tolerance fitto preserve geometric similarly between the relative orientation of the bar 24 and arm 26 on either side of the platform 2.This stabilizer arrangement seems to minimize any tilting or twisting of the platform 2 during raising and lowering of the carriage 4, thus further inhibiting the rollers 8 from locking in their tracks 18.

At each side of the frame, the vertical frame member 10 rises at its base from a fore-and-aft side frame member 30 that rests on the ground. Close alongside the vertical member 10 is a verticallyarranged telescopic two-stage hydraulic pistonand-cylinder unit 32 disposed with its cylinder lowermost. The lower end of the cylinder 34 is pivotally mounted at 36 on the frame base side member 30 close to the ground, and the upper end of the piston rod 38 is connected at 40 to a bracket 42 on the upper end of the vertical member 6 of the carriage 4. Operation of the two piston-and-cylinder units 32 causes the carriage 4to be raised or lowered and the units are preferably synchronized. The piston rod 38 and carriage members 6 are protected by buffers formed on the members 6.

The hydraulic supply for the piston-and-cylinder units 32 is obtained from a power pack consisting of a mains electric motor driving a hydraulic pump (not shown). Control is by means of a handle (not shown) at the end of the platform or frame which operates an hydraulic contrdl valve 44 thorough a Bowden cable. The hydraulic system should be kept under positive pressure at all times, for example by locating a fluid reservoir above the apparatus. Restrictive valves can be used to limit the rate of lowering ofthe carriage to a safe speed. To enable the platform 2 to be lowered, the carriage 4 will normally have to be raised slightly to permit release of the locking mechanism described below.For this purpose, a hand pump may be provided to enable manual operation in the event of a mains power failure, and for freeing a car that would otherwise be trapped on the raised platform. Alternatively an electric pump may be included which operates from the car battery. An emergency transfer lever can be operated to bring either such hydraulic system into use.

The locking mechanism includes a spring loaded latch mounted on each carriage member 6 which engage a fixed abutment on the adjacent frame member 10. The latches are interconnected to prevent independent operation. lot is preferred that the latches can only be released under hydraulic pres sure from the main operating system. This prevents the platform being unlocked without fluid in the cylinders 34 which would result in uncontrolled low ering. The unlocking mechanism for the platform is generally similar in principle to that described in our prior patent application. To unlock the platform to enable itto be lowered, a handle 46 at the front end of the platform is pulled.As well as operating the locks through a Bowden cable connection, the handle acts via a link 48 and lever 50 to rotate a rod 52 that extends horizontally across the machine under the platform 2. An arm is rigidly connected at one end to the middle of the rod 52. The arm 54 extends at right angles to the length of the rod 36 and, with the lever 50 in the position shown, extends almost horizontally under the platform 2. On operation of the lock-release handle 46, the rod 52 will be caused to rotate thus swinging the arm 54 downwardly in the direction of arrow A. If a car is positioned beneath the platform, the arm 54 will come into engagement with the car and thus prevent further rotation of the rod 52 and hence further movement of the handle 46. At this time, the platform locks will not have been released, so that lowering ofthe platform will be prevented.

As well as there being a switch for automactially turning off the hydraulic fluid supply when the platform is in its fully raised position, a further switch is incorporated that switches on the hydraulic pump automatically at a position local to the machine when the controls are operated to lower the platform.

To facilitate the driving of vehicles on and off the platform it is fitted with a short sloping entry ramp 56 and, in the interests of safety, it is desirable that this ramp should be hinged on the main part of the platform so that users are not at any risk of having their feet trapped under the lowermost front part of the ramp.

Claims (11)

1. Car parking apparatus comprising a frame having a pair of upright members; a platform onto which a car may be driven, supported between the upright members; an extendible two stage piston/cylinder mechanism mounted adjacent each upright frame member with its cylinder lowermost and attached to the frame for raising and lowering the platform, means being provided for maintaining the platform in a substantially horizontal orientation while it is being raised and lowered.

2. Car parking apparatus according to claim 1 wherein each cylinder is pivotally attached to the frame.

3. Car parking apparatus according to claim 1 or claim 2 wherein movement of the platform is maintained substantially horizontal by vertically spaced rollers fixed relative to the platform and received on tracks provided on the frame upright members.

4. Car parking apparatus according to any preceding claim wherein the platform is carried on a carriage having vertical upstanding members generally parallel to the upright frame members, the piston/cylinder mechanisms being connected between the frame and the upstanding carriage members.

5. Car parking apparatus according to claim 4 including arms extending forwardly from the carriage upstanding members to an end of the platform.

6. Car parking apparatus according to claim 3 and claim 4 wherein each roller is mounted on a spindle fixed in the carriage upstanding members, and runs in an enclosed track.

7. Car parking apparatus according to any preceding claim including a slider plate assembly on the frame upright members and the platform support for at least limiting the lateral tilt of the platform relative to the frame.

8. Car parking apparatus according to claim 7 wherein the slider plate assembly comprises a plate on each frame upright member and slider blocks on the platform support.

9. Car parking apparatus according to any preceding claim further including a stabilizer assembly comprising a bar extending longitudinally of the frame from the platform support to the free end of an arm pivotally mounted on the frame.

10. Car parking apparatus according to claim 9 wherein the two arms are connected such that they pivot together about their mountings as a frame.

11. Car parking apparatus substantially as described herein with reference to and as illustrated by the accompanying drawings.