GB1600034A - Turnstile - Google Patents

Description

(54) TURNSTILE (71) We, EMI LIMITED, a British company of Blyth Road, Hayes, Middlesex, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statmenent: This invention relates to turnstiles.

Turnstiles are now commonly used for the entrances and exits of urban, rapid-transit and other transport systems. The high rate of which the turnstiles operate, the cost of maintenance and the need to use installed equipment to the fullest extent all demand a reliable turnstile which is easy to service. Turnstiles proposed hitherto have included many precision piece parts requiring expensive manufacture and precise assembly, without producing extremely reliable operation.

It is an object of the invention to provide an improved turnstile.

According to the invention there is provided a turnstile including a rotatable barrier element pivoted in a housing for rotation to sequentially open and close a passage and having dwell setting means to determine positions in the rotation at which the barrier element dwells until displaced, the dwell means including a multilobed cam and at least one cam roller, one to rotate with the barrier element the other fixed, the cam and cam roller being resiliently urged together to cause the barrier element to dwell with a roller in a trough between cam lobes.

The turnstile may also include an index mechanism to control the direction and extent of rotation.

Embodiments of the invention will now be described with reference to the drawings accompanying the Provisional Specification in which: Figure 1 is a plan view in cross-section of the 'head' of milk stool type turnstile, Figure 2 is a diametral elevation, in crosssection of the 'head of Figure 1 and with refer en e to the accompanying drawings in which: Figures 3 and 4 show modifications of parts of Figures 1 and 2 respectively.

A 'milk-stool' turnstile has a housing and a barrier element in the form of a tripod pivoted at the head in the housing to revolve about the axis of symmetry, which axis is inclined upwardly across a passage obstructed in turn by the horizontal, uppermost, tripod leg or barrier element.

The pivot head is subejct to wear and strain and must include means to control the direction in which the turnstile revolves, provide a non-return and free wheel action as required and be easy to service. The head shown in the figures has two main parts, a generally flat support plate 100 and a dished hub 200. The plate is mounted in the turnstile housing and the hub supports the barrier elements and rotates on the support plate.

The hub is preferably a casting in ferrous metal or light alloy and of dished form. The centre of the concave face 201 of the hub 200 has a dwell setting means 202 of three equally placed lobes 211, 212, 213 projecting towards the mouth of the dish. The support plate is a lipped metal plate 101 with a central spindle 102 having pressed on to it a bearing sleeve 103 which may be of plastics. Spindle 102 has an internal thread 104 to receive a bolt 105 which retains the hub 200 to the plate 100, with the aid of a cap 106. Hub 200 has a boss which fits on bearing sleeve 103. A spider and pressure ring 107 has a lobed surface of the same general form as lobes 211, 212,213. Each spider lobe 111, 112, 113 carries a roller or wheel 121, 122, 123 of plastics material and pivoted on a respective axle pin. The spider 107 has a central clearance hole for the hub boss and is fitted around this boss spaced from the boss. A spring 108 urges the spider rollers against dwell-setting means 202 of the casting.

Preferably a thin, e.g. 20 SWG, mild or stainless steel or other smooth ring or washer 109 is placed on surface 202 to provide a smoother track for rollers 121, 122, 123 reducing wear.

The washer is formed to the contour of surface 202 by a stamping process before installation.

At assembly of the hub to the support plate using bolt 105 two p.t.f.e. washers 110, 114, are placed under cap 106 which is then tightened down by bolt 105 to a desired endfloat of the hub on spindle 102 against spring 108. A pawl block 130 is provided on plate 100. Block 130 engages one of the six sides of spider 107 and prevents it turning with hub 200.

The operation of the turnstile, apart from the action of the pawls of pawl block 130 described below, is as follows. Starting with the rollers 121 etc. in the troughs between adjacent hub lobes 211, 212, 213, the hub is constrained to this dwell position by the spring 108. If the hub is rotated rollers 121 etc. ride up the lobes 211, 212,213 and move the spider to compress the spring 108.

So long as the rollers are out of the troughs the spring and rollers tend to drive the hub to this starting position. Thus the hub has three stable dwell positions and will revert to or advance between these positions in a precise positive step-wise manner subject to the action of the pawls. Wear is minimised as the rollers run on the washer 109 and the hub on the long sleeve 103. For maintenance washer 109, rollers 121, 122, 123 and, if required, sleeve 103 are all quickly replaced without precision machining or fitting etc., which delay repair.

Pawl block 130 is mentioned above. This mounts pawls to control direction and extent of rotation and provide free-wheel for emergency use. A ring of teeth, 220, one tooth being indicated at 221, is formed on the inside face of hub 200. In a preferred embodiment the teeth are formed by a nylon or other plastics ring pushed into the casting and engaged on pegs or ribs or other projections spaced to fall within the tooth outline. To assist the fitting of the ring the parts joining together the teeth can be notched to permit the length to be varied. The ring is preferably slightly larger than the available space so that it is compressed at the notched parts and held in by friction alone as a force fit. Typically twelve teeth are provided for a tripod i.e. three position turnstile. Three indexing cam faces corresponding to the troughs of the dwell setting means (222,223, 224) are formed in rim of hub 200 adjacent to toothed ring 220. These can be part of the inserted ring. Two latch elements, 131, 132 and two pawl elements 133, 134 are mounted on block 130. The latch elements are pivoted on block 130 to run on the rim of hub 200 as the turnstile rotates. The pawl elements are mounted on pins 135, 136 screwed into the pawls and rotate in holes in the block, subject to the pawls hitting the block. The pins are bushed with rubber (137, 138) where they pass through the block. This provides resilience so that if the turnstile is pushed against the locking action of a pawl the pin does not bend but the pawl moves back until it touches the block and thereby is supported, removing any strain on the pin. This provides protection against damage caused by abuse of the turnstile.

Means, to be described later, are provided by which the pins 135, 136 may be rotated to either engage or remain clear of the teeth 220.

The latch and pawl elements are shaped so that the latch can hold the pawl clear of the teeth until the latch is lifted by one of cam faces 222, 223, 224. The pawl can then turn to the tooth engaging position moving under the lifted latch element.

In one arrangement of the turnstile head embodying the invention the means to rotate the pins and thus pawls 133, 134 includes for each pin an arm locked to the pin, a light return spring acting on the arm to pull the pawl away from the tooth ring and a solenoid connected to the arm by a stronger spring to pull the pawl into engagement with the tooth ring. The solenoids are of the normally energised type and thus when electrical power is applied the pawls are urged to engage the tooth ring provided the latches are clear of the pawls.

Thereafter the turnstile can only be moved when a solenoid is de-energised. If a solenoid is momentarily deenergised the return spring turns the pawl from under the respective latch to disengage the tooth ring. The re-energised solenoid tries to pull the pawl back via the strong spring but the latch prevents it. The turnstile is thus freed to rotate in one direction, set by the pawl selected and until a cam face 222, 223, 224 moves the latch to release the pawl to engage a tooth and stop further movement.

Clearly several steps in turn can be permitted by a suitable electrical, e.g. bistable circuits, or mechanical, e.g. a pawl and ratchet, 'memory'.

By suitable operation of the solenoids the turnstile can be locked, allowed to move stepwise or freely in one direction on the other or move freely in both directions, e.g. as a safety feature for emergency exit. The use of normally energised solenoids to prevent movement ensures that the turnstile free-wheels on a power failure occurring. The pawls can have nylon or other plastics tips to reduce noise.

The turnstile described above has a particular advantage in that by the arrangement of the various parts wear is reduced without the use of heavy or cumbersome construction. If, due to very heavy use, e.g. 500 to 1000 operations per hour, wear occurs the parts subject to wear are easily replaced and it is simple for a mechanic to remove the whole assembly from the barrier element by removing three bolts, so that the barrier can be replaced or repaired, without great loss of time of use.

This is considerable advantage when traffic is heavy.

Figures 3 and 4 show a modification of the arrangement in Figures 1 and 2 which modification, inter alia, reduces the possibility of manipulation of the turnstile to cause it to adopt an incorrect position, e.g. with the barrier arms 'out-of-phase' with the electrical control mechanism.

To this end additional pawls are provided and arranged for controlled operation during the stepping of the barrier arms to ensure that once the stepping action is commenced the barrier cannot be reversed to latch in an intermediate position but will only latch when it has been advanced the correct amount. As described above a pawl is withdrawn from the latched position to permit rotation until a cam face causes it to relatch at the next correct orientation. However it has been found that users could manipulate the barrier and bring about latching in an intermediate position.

To prevent this pawls 133, 134 are augmented with additional pawls 2133, 2134 respectively. These additional pawls have long tails which ride on a tooth of ring 220 while pawls 133 or 134 are in a notch between teeth.

Further the latch elements 131, 132 are replaced by latch plate 313 which engages control arms 335,336 on spindles 135, 136 respectively. To permit the barrier to move anticlockwise, in Figure 3, spindle 135 is tumed, e.g. as described above to move control arm 335 from overlap with latch plate 313 to engage a nose 3131 thereof and thereby hold pawls 2133 and 233 clear of the tooth ring 220 against spring 324 housed in pawl 133. Spring 314 pushes pawl 134 against tooth ring 220.

Each control arm 315, 335,has a a depending lipped flange part which is pinned to the respective shaft 135, 136. This flange permits lost motion between pawls 134, 133 and addition at pawls 2134, 2133. A spring, such as 316, acts on the additional pawls.

Latch plate 313 is tilted by the cam face, such as 222, 223, 224, as shown in Figure 3A, to permit the pawls and additional pawls to 'cover' the motion of the tooth ring and prevent reversal thereof.

WHAT WE CLAIM IS: 1. A turnstile including a rotatable barrier element pivoted in a housing for rotation to sequentially open and close a passage and having dwell setting means to determine positions in the rotation at which the barrier element dwells until displaced, the dwell means including a multilobed cam and at least one cam roller, one to rotate with the barrier element the other fixed, the cam and cam roller being resiliently urged together to cause the barrier element to dwell with a roller in a trough between cam lobes.

2. A turnstile according to claim 1 including an index mechanism to control the direction and extent of rotation.

3. A turnstile according to claim 2 in which the index mechanism includes a set of pawls for each direction of rotation and latching means to cooperate with cam faces of the barrier element indicating stable barrier positions to permit movement of the barrier from one such position to the next only in one direction.

4. A turnstile substantially as herein described with reference to the drawings accompanying the Provisional Specification.

5. A turnstile substantially as herein described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. orientation. However it has been found that users could manipulate the barrier and bring about latching in an intermediate position. To prevent this pawls 133, 134 are augmented with additional pawls 2133, 2134 respectively. These additional pawls have long tails which ride on a tooth of ring 220 while pawls 133 or 134 are in a notch between teeth. Further the latch elements 131, 132 are replaced by latch plate 313 which engages control arms 335,336 on spindles 135, 136 respectively. To permit the barrier to move anticlockwise, in Figure 3, spindle 135 is tumed, e.g. as described above to move control arm 335 from overlap with latch plate 313 to engage a nose 3131 thereof and thereby hold pawls 2133 and 233 clear of the tooth ring 220 against spring 324 housed in pawl 133. Spring 314 pushes pawl 134 against tooth ring 220. Each control arm 315, 335,has a a depending lipped flange part which is pinned to the respective shaft 135, 136. This flange permits lost motion between pawls 134, 133 and addition at pawls 2134, 2133. A spring, such as 316, acts on the additional pawls. Latch plate 313 is tilted by the cam face, such as 222, 223, 224, as shown in Figure 3A, to permit the pawls and additional pawls to 'cover' the motion of the tooth ring and prevent reversal thereof. WHAT WE CLAIM IS:

1. A turnstile including a rotatable barrier element pivoted in a housing for rotation to sequentially open and close a passage and having dwell setting means to determine positions in the rotation at which the barrier element dwells until displaced, the dwell means including a multilobed cam and at least one cam roller, one to rotate with the barrier element the other fixed, the cam and cam roller being resiliently urged together to cause the barrier element to dwell with a roller in a trough between cam lobes.

2. A turnstile according to claim 1 including an index mechanism to control the direction and extent of rotation.

3. A turnstile according to claim 2 in which the index mechanism includes a set of pawls for each direction of rotation and latching means to cooperate with cam faces of the barrier element indicating stable barrier positions to permit movement of the barrier from one such position to the next only in one direction.

4. A turnstile substantially as herein described with reference to the drawings accompanying the Provisional Specification.

5. A turnstile substantially as herein described with reference to the accompanying drawings.