GB2296933A - Ladder warning device - Google Patents

Abstract

An audible warning system for ladders consisting of more than one section, comprises a pressure plate 7 remains inactive until depressed by the persons foot, using the ladder. The plate is situated on the last double rung 8 of the extendible section of the ladder and connected to audible warning device 4 retained within a case 1 on the ladder stile. An incline angle finder 3 in the case 1 remains inactive when ladder is at a safe working angle as no electrical current flows to warning device 4. When the ladder is at an unsafe angle the liquid retained within the angle finder 3 contacts the electrical poles allowing current to flow from the power pack, to the incline angle finder, and warning device retained within the case 1. A fail safe switch is provided which when depressed causes an audible sound and a light emitting diode to light up thus, showing effectiveness of the device.

Description

A PORTABLE AUDIBLE LADDER ALARM THE INVENTION Is a portable, audible warning horn buzzer alarm system for use with extension ladders, which includes a fail safe light to allow the user to know if the batteries are flat or the horn buzzer is not operative. Also inciuded is an incline an5le finder alarm to allow the user to know when the ladder is at the correct working angle .

THE LADDER The metal type eg: Aluminium, the tye intended to be leant against a vertical surface or the type fixed to or supported by an emergency service vehicle eg: Fire render lorry, which extends two, three, four or five tines its own height or the type used to enable a person to bet to the top of 2 roof, known as a roofing ladder.

THE AIM OF THE INVENTION Is to allow the person used an extension ladder either ascending or descending to know via an audible sound that they are standing, passin6 or restin6 on the first or last double rung of the extended section of the ladder without the aid of a ers stood at the bottom of the ladder telling the that they must move their foot inwards, forwards or (sideways for the roofing ladders) so as to locate the next rung of the ladder under the extended section (or the ladder to the ground from tne roof) therefore preventin6 them from missing this rung or ladder completely anf falling to the ground causing themselves and others serious injury.It has previously been prorosed that a warning light be built into the ladder styles and operated ty a foot activated switch at tne foot of the ladder for example 4,311,208. However the need for mains electricity and the switching mechanism being incorporated with the styles of tne finder means it cannot be used vithout the availability of an extension ie;d, for use on tne outside of buildings as in decorating, window cleaning, retiling roofs, do it yourself work or emergency service work, when carrying heavy objects such as an injured person down the ladder which can be extremely dangerous at the change of step, width, hei6ht etc.

The looking down to see the change of step can also be extremely dangerous, as this may cause the operator to 50 dizzy and fall causing injury to himself and more to the patient.

The Inclusion of an Incline angle Alarm within the design is to allow the user of the ladder to know when the lauder is tt the correct working angle without the need of judgement, although ;adders are fitted with a vertical line this does not rule out mis-judeement and therefore ctn cause the bottoiii of the ladder to slip outwards, causing injury to the operator. Although it has been previously proposed that an inclination Indicator be fitted to ire Fender ladders, this is not so for free standing ladders such as those used within the building industry or the @IY market.

THE ALARM BUZZER HORN Is of the audible type which is of an electrical nature, which when a current of electricity, supplied by a power pack eg: battery, passes through, it gives off a loud audible sound, by means of vibrating reeds, therefore the Alarm Buzzer Horn does not have to be seen to be effective.

THE OPERATING MECHANISM Is of the pressure pad or plate type, which is formed by a piece of sprung metal, steel or similar material, placed across two insulated poles, so that when depressed to contact the ladder run6 allows the electrical current from the power pack to pass to the Buzzer Horn via wires to make an audible noise.

The metal pad or plate can be depressed via foot or hand to activate the alarm and released to de-activate, therefore the power pack lasts longer.

The invention can be either of a permanent fixture to the ladder or can be moved from one ladder to another or removed completely when not in use.

The clips that hold the invention to the ladder rung can be used as insulting poles if made of plastic or similar springy material so as to allow the invention to be moved from one ladder to another or metal clips as in a jublee clip with insulators placed between pressure pad and clips, this allows the invention to become niore permanent in nature.

THE INCLINE ANGLE FINDER Is in tne nature of blas bubble which is half full of liquid metal e: ercury, which is conductive to electricity, set within the glass bubble are two electrical poles, which when covered by the lIquid etal allows an electrical current to pass through to the Form Buzzer, which then emits an audible sound, allowing the operator to know that the ladder is set at the wrong angle. rhis switch is fixed to or within the case which houses the battery power back and ail the other electrical fitments, barring the actual pressuie plate and earth wire. This battery case is affixed to the vertical side styles of the ladder.

THE FAIL SAFE Is a push button switch which when depressed allows an electrical current to pass to the L.B.D. (light Emitting Diode) and the Horn Buzzer to sound, when released closes off the current, therefore turning off the libht and te Horn Buzzer.

In order that the invention be fully understood a preffered embodiment of the invention will now be described by way of examples with reference to the accompanying drawings in which the single figures are a perspective view of the inaividual circuits and of the complete ladder warning system.

FIGURE ONE Refers to the wirin6 dia6ram of the battery test fail safe.

When switch 2 is depressed, an electrical positive current flows via wire 1A through the depressed switch 2 to the L.E.D (light Emitting Diode) 3 via wire 1a, on to Horn Buzzer 4 via lA. The current then returns from Horn Buzzer 4 to battery power pack 1 via wire 2A, therefore completing the circuit causing the Horn Buzzer 4 to make an audible sound and the L.E.D (Light Emitting Diode) 3 to glow, therefore allowing the operator to see that the battery power pack 1 is fully charged and operational and that the Horn Buzzer 4 is fully operative.

FIGURE TstO Refers to the wiring diagram of the liquid metal Incline Angle Finder.

When the ladder is set at correct angle Horn Buzzer 4 is inoperative, but when ladder is set at incorrect angle, tne liquid metal eg: mercury, contained within glass bubble of the Incline Angie Finder 6 flows covering both electrical terminals built Into the glass bubble Incline Angle Finder 6, therefore allowing a positive electrical current from the power pack buttery 1 via ire 3A to pass through to the Horn Buzzer 4. The current then returns to battery power pack 1 viz wire 4h, thus completing the circuit causing the Horn Buzzer 4 to make an audible sound and allowing the operator to know that the ladder is leant at the wrong angle and therefore dangerous to use unless moved to the correct position.

FIGURE THREE When pressure plate, pad or bar 5 is depressed to contact ladder rung 7, a positive electrical current flows from battery power pack 1 via wire SA through pressure plate, pad, bar 5 to ladder rung 7. The positive electrical current flows through ladder rung 7 to ladder style 8, which is connected to ladder rung during manufactor. The positive electrical current then travels through wire 7k to Horn Buzzer 4. Wire 7A is fixed to ladder style 8 with a self tapping screw or similar fixing.The positive electrical current then passes through Horn Buzzer 4 to wire 8, wire 8A then returns to the battery power pack 1, the negative terminal, therefore completing the circuit and causing the reeds within alarm horn buzzer to vibrate and creating an audible sound so that the operator knows that they are on the last double rung of the extended part of the ladder.

FIGURE FOUR Refers to complete circuit of the uesign that is incorporated within a case of either plastic or similar material, metal e6: aluminium or sinilar material. The case can be square, round or cylindrical so as to allow ease of fixing to the side styles of the ladder, by screw or double slced velcro or inside the runÖ of ladder.Battery poser pack 1 supplies all three individual circuits, although individual, they are as one with parallel switches eg: pressure, liquid anc ush button switch and in series warning L.E.D and buzzer horn. íth the circuits beinb individual within one, it allows the operator to know which alarm Is sounding therefore eliminating confusion.

Figure la Refers to invention in situ on the last double rung of extended section of ladder. all numbers mentioned refer to components of invention, Eg No 10 refers to case which incorporates all electrical circuits, switches, liquid 3 push button 2, excepting pressure switch 5 which has to be connected to last double rung 7 of the extending section of the ladder. Warning light 3 and buzzer horn 4 and case 10 is attached to ladder style Key to figure la No 1 refers to power pack battery not shown in diagram No 2 refers to push button fail safe test No 3 refers to L.E.D light emitting diode No 4 refers to audible alarm No 5 refers to pressure switch No 5a refers to the positive wire from power pack 1 No 5b refers to releasably secureable clips.

No 6 refers to incline angle finder.

No 7 refers to last double rung of the extended section of the ladder No 7a refers to the negative wire to complete the circuitry No 8 refers to the side style of the extended section of the ladder No 9 refers to the lower section of the ladder No 10 refers to the case in which are contained all the electrical components

Claims (7)

1. Claims 1. A portable warning system for use with ladders consisting of more than one section, comprising of a switch attached to last double rung of the extendible sections of the ladder (to activate the audible warning device defining the last double rung of the extendible sections), A case to retain the power source and electrical components with an incline angle finder contained within the main casing.
2. 2. A device according to claim 1 wherein a means of releasably securing the case to the ladder is attached to or forms part of the main casing.
3. 3. A device according to claim 1 and claim 2 wherein a means of releasably securing the switch mechanism forms part of or all of the switch mechanism.
4. 4. A device according to claims 1 to 3 wherein the audible warning device becomes operable from the power supply when the said switch is activated.
5. 5. A device according to claims 1 to 4 wherein the said switch is activated by the operators foot contacting the said switch situated on the last double rung of the extendible section of the ladder.
6. 6. A device according to claim 1 to 5 may include an incline angle finder in order to determine the safe working angle of the ladder.
7. 7. A device according to claims 1 to 6 wherein a means of testing the effectiveness of the device may be included as part of the device.