Finishing-contact System For Swimming Competitions

Abstract

This invention relates to a finishing-contact system for swimming competitions, wherein compressible contact cables having conductors elastically spaced from each other in unloaded state of the cable are mounted on a touching plate mounted on the finishing face of a basin, said cables being adapted to be compressed and said conductors being adapted to close an electrical control circuit upon pressure against said plate.

Description

This invention relates to a finishing-- contact system for swimming competitions, comprising a perforated plate suspended at the finishing face of the track of a competitor. In prior devices of this type a system of uniformly distributed tubes is fixed between the rear side of the perforated plate and the finishing face of the basin. All tubes of the system are connected to a common pneumatic relay in which an electrical contact is closed when the pressure in the tube system increases. Upon arrival of a competitor, said plate is touched by the competitor and is slightly deformed and displaced towards the finishing face of the basin so that some portions of the tube system are compressed. Therefore, the pressure in the tube system is slightly increased due to local compression of at least one tube. By this pressure rise the contact of the pneumatic relay is closed and a control circuit is energized. This prior system has various drawbacks. The measuring system has low sensitivity. It greatly depends on temperature variations. Due to the substantial differences of the distance of particular places of the tube system from the pneumatic relay, the differences in transmission time of the pressure wave from various places of the tube system to the pneumatic relay are no longer negligible. Moreover, the propagating speed of pressure waves in the tube system and the speed of response of the pneumatic relay depend on the intensity of the pressure waves. Therefore, the measurement depends on the force with which the competitor presses against the perforated plate.

It is an object of this invention to overcome the above drawbacks and to provide a simple and reliable contact system wherein a contact may directly be closed by pressure against any place of the perforated plate. In prior systems of this type, electrical conductors have been uniformly distributed in two parallel planes within an elastically compressible envelope mounted on said finishing face of the basin, for obtaining immediate closure of the control circuit when the competitor touches any desired portion of the envelope. However, this system was found to be complicated and difficult to manufacture with the required sealing properties of the envelope enclosing the electrical conductors.

This invention is based on the idea of combining the advantages of the above prior systems but avoiding their drawbacks. The system according to this invention is broadly characterized by a system of contact cables located between said perforated plate and said finishing face, said cables having each two flat conductors maintained at a distance from each other by elastical means in unloaded state of the cable and enclosed together in an elastic tightly sealed tube. It was found that practically a very simple system of contact cables is sufficient. The flat section of the cables allows simple disposition of the same between the perforated plate and the finishing face of the basin in a position suitable for proper operation of the contacts. It is relatively simple to sufficiently seal the ends of the cables.

One embodiment of this invention is shown, by way of example, in the accompanying drawing wherein

FIG. 1 is a vertical section through the finishing - contact system,

FIG. 2 is a partial section of the system on a larger scale,

FIG. 3 illustrates the construction of the contact cables and

FIG. 4 illustrates one embodiment of the seal at the ends of a contact cable.

The illustrated system comprises a plate 1 of rectangular shape mounted in a position parallel to the finishing face 2 of a track in a basin for swimming competitions. The plate 1 should have a suitable stiffness. Preferably, a plate of plastics material is used, for instance a plate of PVC having a thickness of 4 mm. The height of the plate 1 is 700 mm and its length in horizontal direction is 2400 mm. The plate 1 has a perforation (not shown in the drawing) practically on its entire surface allowing easy exchange or passage of water from the space between the plate 1 and the face 2 through the plate. The plate 1 is suspended by means of four screws fixed in the face 2. As may be seen from FIG. 1, these screws 3 extend with some clearance through bores of plate 1, the distances between the screws and the bores being so designed that the plate is supported on the lower screws 3 but are only maintained in vertical position by the upper screws 3. In this way, easy displacement of the upper plate portion without friction in a direction perpendicular to the finishing face 2 is obtained. The plate 1 has a horizontal flange 4 at its upper end, this flange covering and extending rearwardly over the finishing face and the adjacent rim portion of the basin.

The rear face of the plate 1 carries contact cables 5 extending in horizontal direction. Two cables 5 are disposed at a relatively short distance from each other in the upper portion of the plate 1 while two contact cables are disposed at a relatively wide distance from each other in the lower portion of the plate 1. A similar contact cable is fixed on top of the flange 4. Preferably the contact cables are removably attached to plate 1, for instance as shown in FIG. 2. It is seen from this figure that the contact cable is cemented upon a portion 6 of a "Velcro"--attachment, while the other portion 7 of this attachment is cemented to the rear side of the plate 1. Portions 6 and 7 of this attachment or closure are provided with small projecting hooks of plastics material or the like and sufficiently adhere to each other after being pressed onto each other by engagement of the hooks, but also allow easy removal of a contact cable 5, for instance for exchange of a defectuous cable.

Construction of the cables is illustrated in detail in FIG. 3. The cables have a first contact in the form of a metal strip 8 and a second contact strip 9 of a slightly curved shape for normally avoiding any contact between conductors 8 and 9. Contact 9 is cut in meander form in order to increase its flexibility. Conductors 8 and 9 are insulated from each other by means of W - shaped insulating strips 10. The contacts 8 and 9 and insulating strips 10 are enclosed in an impervious mantle or tube 11 of plastics material. The mantle 11 has a projecting rib 12 divided into sections by gaps in order to increase the local pressure acting onto the remaining rib sections upon displacement of the plate 1 towards the finishing face 2.

The ends of the contact cables 5 should be tightly sealed. FIG. 4 shows one embodiment of sealing means at the ends of a cable. One of the ends is closed by means of a tube 13 of plastics material cemented upon the end of the cable mantle 11 by means of an absolutely impervious and waterproof cement. An insulating sheet 14 is put between the ends of conductors 8 and 9. At the other end of the contact cable, the mantle 11 is removed for allowing connection of the conductors 8 and 9 to the conductors of a cable 15. A sheet 16 of insulating material is inserted between conductors 8 and 9 of the contact cable and the blank conductors of cable 15 for preventing short circuits. A tube 17 of plastics material covers adjacent ends of the insulating mantle 11 of the contact cable and of the insulation of cable 15, perfect sealing of the connection being obtained by the use of a waterproof cement as mentioned above.

All cables 15 connected each to a contact cable 5 of a plate 1 are connected in parallel to an electric or electronic time counter for discontinuing counting when the circuit is closed by compression of at least one of the contact cables 5. Such compression and closure of an electric circuit occurs whenever a competitor touches the plate 1, whereby the latter is displaced towards the finishing face 2. In this case, at least one of the contact cables 5 is compressed and its conductors 8 and 9 touch each other. When the competitor has to turn once or several times at the face of the basin where plate 1 is mounted, the control circuit will be closed whenever the competitor turns at the plate. Of course, the electric control pulses produced during such intermediate passages of the competitor do not stop the time counter, but they may be used for indicating intermediate times of the competition. The last pulse only, which is selected by suitable means, stops the counter for indicating the total time. On his arrival the competitor first touches the plate 1 in its upper portion or even at its upper side. For this reason, it is desirable to provide the contact cables at shorter intervals from each other in the upper portion of plate 1 and even on the upper rim of plate 1.

Claims

I claim:

1. Finishing-contact system for swimming competitions, comprising a perforated plate, means for suspending this plate at the finishing face of the tract of a competitor and allowing displacement of the plate in a direction perpendicular to said finishing face, a number of horizontally disposed contact cables located between said plate and finishing face respectively, said cables having each two flat conductors maintained at a distance from each other by elastical means in unloaded state of the cable and enclosed together in an elastic tube, sheets of insulating material inserted between the conductors at the ends of each cable and sealing tubes applied to each end of each cable within reach of one of said sheets of insulating material. Claim 2. A finishing-contact system for swimming competitions according to claim 1 in which said elastic tube is sealed at each end thereof, and connecting means are provided so that said flat conductors are removably connected to said plate, said connecting means continuously extending and acting on the full length of said cable. Claim 3. A finishing-contact system for swimming competitions according to claim 1 in which said contact cables are electrically connected together. Claim 4. A finishing-contact system for swimming competitions according to claim 1 in which a basin is adjacent which has a rim, and said plate has a horizontally extending flange covering and extending rearwardly over the upper edge of the finishing face onto the adjacent horizontal rim surface of the basin, and an uppermost contact cable is mounted on said flange. Claim 5. A finishing-contact system for swimming competitions according to claim 1 which said contact cables are disposed at shorter intervals in the

upper portion of said plate than in the lower portion thereof. 6. A finishing-contact system for swimming competitions according to claim 1 in which said elastic tube is flat and includes a projecting rib on at least one of its flat sides. Claim 7. A finishing-contact system for swimming competitions according to claim 1 in which said contact cables are removably mounted on said plate by means of a hook fastener.