Claims:We claim:

1. Device for a brake motor in an assembly line for checking, displaying and adjusting the change in brake-rotor or brake-disc thickness, the device comprises:

(a) an air-gap checking and displaying device, and

(b) an air-gap adjusting arrangement;

wherein a predetermined air-gap is pre-set between the brake-rotor or brake-disc and the coil housing by means of a micro-switch, actual air-gap displayed by means of an indicating device and subsequently the deviating air-gap is adjusted by means of an air-gap adjustment arrangement for effective motor braking operation.

2. Device for a brake motor in an assembly line as claimed in claim 1, wherein the brake motor applies brake on the assembly line conveyor and a brake rotor shaft rotating about an axis for mounting the rotating brake rotor arrangement, the arrangement further comprises:

- brake motor end shield;
- armature plate;
- brake disc with an original thickness t;
- coil housing;
- hub mounted on the brake rotor shaft;
- electromagnetic coil;
- a plurality of springs;
- brake rotor shaft rotating about brake rotor axis;
- stationary disc,
- metallic dampening plate provided between the stationary disc and the coil housing and integrated therewith for pushing the brake plate uniformly;
- a plurality of fixing screws provided on the motor end shield;
- a plurality of internally threaded setting bolts for tightening and loosening the corresponding surrounding the respective fixing screws;

wherein coil housing also accommodates a coil and a plurality of springs for applying brake by energization of the coil to generate electromagnetic field for brake-motor operation as and when required.

3. Device for a brake motor in an assembly line as claimed in claim 2, wherein the stationary disc moves closer to the brake disc with the decrease in thickness of the brake-disc, thereby increasing the length of the travel of the stationary disc to increase the pre-set air gap.

4. Device for a brake motor in an assembly line as claimed in claim 1, wherein the air-gap checking and displaying device is a battery operated unit placed in between the brake disc mounted on brake rotor shaft and the stationary disc and comprises:

- at least one base for protecting and mounting the micro-switch;

- DC battery for supplying electric current to the circuit;

- at least one pre-set spring loaded switch;

- at least one lever made of a metallic strip which is supported by the spring; and

- at least one light emitting diode (LED);

wherein the metallic strip lever closes and touches the spring loaded switch, the contacts inside the switch complete the circuit and by closure of the contact points, the LED glows to indicate the increased brake rotor air-gap.

5. Device as claimed in claim 4, wherein the stiff metallic strip lever is actuated by external force to quickly flip for making contact with the switch button to complete the electrical in order to glow the LED to indicate an increased air-gap with respect to the pre-set limit thereof.

6. Device as claimed in claim 4, wherein after readjustment of the air-gap to the pre-set limit, the stiff metallic strip lever flips back to its original position, thereby discontinues current supply to the LED to indicate the return to pre-set air-gap by opening the circuit.

7. Device as claimed in anyone of the claims 1 to 6, wherein the battery is a DC battery.

8. Method for displaying the change in air-gap between the armature plate and coil housing by means of the device claimed in claims 1 to 7, wherein the metallic strip quickly flips when a predefined force is applied on it and flips back with a high speed, when the force decreases below a predefined limit, thereby, when the strip closes and touches the spring loaded switch, the contacts inside the switch completes the electrical circuit and the LED glows to indicate the actuated condition of the micro-switch indicating the increased brake rotor air-gap.

9. Method for resetting the air-gap by using the device for a brake motor in an assembly line as claimed in anyone of the claims 1 to 7, wherein the plurality of hollow setting bolts are used for precisely adjusting air-gap, the method comprises the steps of:

(i) loosening the fixing screws by attaching the brake rotor assembly to the motor end-shield by approximately half a turn;

(ii) loosening the brake rotor assembly from the motor end shield by rotating the threaded hollow setting bolts surrounding the fixing screws and turning counter clockwise into the brake coil housing;

(iii) turning the fixing screws by a required amount as a function of the required air-gap decrease, until the desired nominal or pre-set air gap for obtaining effective brake-rotor operation, as measured by using the appropriate feeler gauge.

(iv) turning the fixing screws clockwise to facilitate the movement of the brake coil housing towards the metallic anchor plate for reducing the air gap accordingly;

(v) re-securing the brake coil housing firmly against the motor end shield by rotating the hollow setting bolts turning clockwise or moving out of the brake coil housing;

(vi) tightening the fixing screws by appropriate torque;

(vii) re-checking and measuring the air gap at multiple locations for checking appropriate spacing;

(viii) repeating the preceding method steps as required, until the nominal air gap is uniform and consistent all around the brake rotor assembly; and

(ix) finally, checking the air gap in the brake rotor assembly by placing a feeler gage between the metallic anchor plate and the brake coil housing.

10. Method for resetting the air-gap by using the device for a brake motor in an assembly line as claimed in anyone of the claims 1 to 7, wherein the plurality of hollow setting bolts are used for precisely adjusting air-gap, the method comprises the steps of:

(i) loosening the fixing screws by attaching the brake rotor assembly to the motor end-shield by approximately half a turn;

(ii) loosening the brake rotor assembly from the motor end shield by rotating the threaded hollow setting bolts surrounding the fixing screws and turning counter clockwise into the brake coil housing;

(iii) turning the fixing screws by a required amount as a function of the required air-gap increase, until the desired nominal or pre-set air gap for obtaining effective brake-rotor operation, as measured by using the appropriate feeler gauge;

(iv) turning the fixing screws counter-clockwise to facilitate the movement of the brake coil housing away from the metallic anchor plate for increasing the air gap;

(v) re-securing the brake coil housing firmly against the motor end shield by rotating the hollow setting bolts turning counter clockwise or moving into the brake coil housing;

(vi) tightening the fixing screws by appropriate torque;

(vii) re-checking and measuring the air gap at multiple locations for checking appropriate spacing;

(viii) repeating the preceding method steps as required, until the nominal air gap is uniform and consistent all around the brake rotor assembly; and

(ix) finally, checking the air gap in the brake rotor assembly by placing a feeler gage between the metallic anchor plate and the brake coil housing.

Dated: this 25th day of November, 2015. SANJAY KESHARWANI
APPLICANT’S PATENT AGENT , Description:FIELD OF INVENTION

The present invention relates to geared motor brakes used in any manufacturing shop floor. In particular, the present invention relates to device for detecting the air gap between the brake-liners in a motor brake. More particularly, the present invention relates to a simple and cost-effective device for checking, displaying and adjusting the brake rotor or brake-disc wear.

BACKGROUND OF THE INVENTION

Generally, any manufacturing shop floor or assembly line includes a large number of conveyors for moving the components and/or sub-assemblies for carrying out machining/assembly and other relates activities. These conveyors are equipped with dedicated brake motors for intermittently starting and stopping the conveyors for processing of components-sub-assemblies carried thereon at different locations for a predetermined length of time. The main purpose of brake motors is to apply brake for stopping the movement of the conveyors and also to prevent movement until machining/assembly operation is in progress at a particular location and only when it is safe and desirable to move the conveyors further, the brake motor releases the brake to allow further movement of the conveyor.

In a typical brake motor configuration, the rectifier energizes the brake coil, which in turn attracts the stationary brake disc by removing the pressure between the stationary disc and the brake disc in order to allow the motor to further rotate freely. An opposite action takes place during the stopping of the brake motor on conveyors. In this case, the rectifier de-energizes the brake coil to enable the brake springs to create pressure between the stationary disc and the brake disc, which develops a frictional force between these and thereby brake motor is stopped from rotating and this in turn stops the conveyor for carrying our operations thereon.

The failure of a brake motor operation can prove to be fatal to the equipment as well as personnel.

A typical standard motor brake is “spring-set”, so when power is removed and the brake is de-energized (power-off), the Brake springs exert a force against the armature plate in turn preventing the brake rotor (or brake disc) from rotating. Whereas, when the brake coil is energized (power-on), a magnetic field builds and pulls the armature plate across the air gap to the brake casing, which releases the brake rotor and allows the motor shaft to rotate freely.

Brake air gap is an important feature in any brake motor operation. In order to obtain optimal brake performance and maximum brake life, it is necessary to periodically check and reset the brake air gap. As the brake rotor wears and decreases in thickness, the air gap increases.- If this air gap is too large, the brake coil may not develop sufficient magnetic force to pull the metallic armature disc through this larger air gap and thus brake may drag.

Wear Assessment of brake rotor (brake disc) is required to be done periodically to check for ascertaining the serviceability thereof. If any brake rotor approaches the minimum permissible thickness, then it should be replaced immediately.

Similarly, when the brake pad is worn out, the pad should be replaced immediately to maintain proper brake operation and ensure safety of the personnel and for thwarting any untoward incident.

Micro Switch or miniature snap-action switch is one type of momentary contact switch widely used in automotive, industrial and medical instruments as a sensor. The actuator of these micro-switches often has a hinged wheel placed above a push button. This micro-switch is also widely used in control system applications such as a door interlock, safety switches in elevators, vending machines etc.

Since these micro-switches have a diverse range of engineering applications, they are available in various configurations, made of different housing materials and with numerous styles of actuators.

A resistor is a passive two-terminal electrical component which implements the electrical resistance as a circuit element. Normally, the resistors act to reduce the current flow, and at the same time to lower the voltage levels within electrical circuits.

A light-emitting diode (LED) is a two-lead semiconductor light source. It is a diode, which emits light when activated.

An electric battery is a device consisting of one or more electrochemical cells which convert stored chemical energy into electrical energy.

DISADVANTAGES WITH THE PRIOR ART

An increased air gap in brake rotor/liner would cause over-travel, which is an unsafe condition and may cause the equipment breakdown or even an accident. There is no conventional hitch control valve in the existing brake-gap analyzer. At present, a frequency based preventive maintenance is done on brake motors for implementing a zero-breakdown regime. This includes a condition-based monitoring (CBM) by using the online parameters; a time-based monitoring; and preventive maintenance carried out with the help of machine generated plans. In addition, operators also carry out autonomous maintenance (JH or Jishu Hozen under TPM). Any minor stoppages are also eliminated.

The existing method for checking the brake liner/motor air-gap includes manual checking by the operator using a filler gauge. However, there is always a possibility of a human error. Another method is performing a time-based replacement of brake liners/discs. This proves to be a costly solution due to high cost of replacement, because the liners/discs may be replaced even in still serviceable condition or before their deterioration.

The major disadvantages with the existing method for checking the brake liner air gap or for checking the brake rotor/disc thickness are as under:

• Checking the brake line air-gap is a lengthy procedure.
• Checking brake liner air-gap and thickness of the brake disc is a time consuming process.
• Close monitoring of brake gap and brake disk thickness is required at regular intervals to ascertain serviceability thereof.

Moreover, major drawbacks in checking brake-liner air-gap and finding the brake disc thickness are as under:

• Skilled personnel required to adjust the brake air-gap.
• Requires dedicated manpower to check brake-liner air-gap and the brake disc thickness.
• Continuous monitoring of the brake motor is to be done for above purposes.
• Requires special measuring instruments.
• Requires frequent calibration of the measuring instrument.
• Online measurements are not possible due to fear of accidents.
• Only off-line measurements of the brake liner air-gap and brake disc thickness are possible until now.

OBJECTS OF THE INVENTION

Some of the objects of the present invention - satisfied by at least one embodiment of the present invention - are as follows:

An object of the present invention is to provide a reliable device for checking the air-gap in the brake rotor/liner in a brake motor on any machinery.

Another object of the present invention is to provide a cost-effective device to monitor the air-gap in the brake rotor/liner in a brake motor on any machinery.

Still another object of the present invention is to provide a method for online monitoring of the brake rotor/line air-gap of a brake motor on any machinery.

Yet another object of the present invention is to provide a safe method for checking the air-gap in the brake rotor/liner in a brake motor on any machinery.

A further object of the present invention is to provide a method for checking the air-gap in the brake rotor/liner in a brake motor on any machinery which allows any available personnel to easily read the brake disc wear indications.

A still further object of the present invention is to provide a device for checking the air-gap in the brake rotor/liner in a brake motor on any machinery which is maintenance free.

A yet further object of the present invention is to provide a device for checking the air-gap in the brake rotor/liner in a brake motor on any machinery, which can be interlocked with the equipment.

One more object of the present invention is to provide a device for checking the air-gap in the brake rotor/liner in a brake motor on any machinery, which can be easily mounted on any surface, i.e. offers flexible mounting thereof.

Another important object of the present invention is to provide a device having a minimum number of components for checking the air-gap in the brake rotor/liner in a brake motor on any machinery.

Further important object of the present invention is to provide a compact device for checking the air-gap in the brake rotor/liner in a brake motor.

Still further important object of the present invention is to provide a battery operated device for checking the brake rotor/liner air-gap in a brake motor.

These and other objects and advantages of the present invention will become more apparent from the following description when read with the accompanying figures of drawing, which are, however, not intended to limit the scope of the present invention in any way.

DESCRIPTION OF THE PRESENT INVENTION

In order to obtain the optimal brake performance and achieve the maximum motor brake service-life, it is necessary to periodically check and reset/adjust the brake rotor/liner air-gap. Since the brake rotor wears continuously during operation and thereby decreases in thickness, its air-gap increases continuously. When this air-gap becomes too large, i.e. beyond the permissible levels, the brake coil will not have sufficient magnetic force to pull the metallic armature disc through this increased air-gap and the brake will not apply effectively.

Whenever air-gap increases or thickness of the brake disc decreases, detector will generate an indication by means of an LED. Accordingly, the following are the important components of the device in accordance with the present invention:

A micro switch, which can be operated using a very small force and also possibly by using just a very small movement. A 9V battery produces voltage and delivers electrical current as the primary “source” of electrical energy used, which is not stored therein, but rather produced by means of a series of chemicals stored therein.

A Light Emitting Diode or LED consists of a semiconductor diode, which on energizing thereof, emits light by means of the electroluminescence process.

Accordingly, the micro switch uses a stiff metal strip supported by a spring, which suddenly flips when a certain force is applied on the micro-switch button and it also flips back with a high speed when this force decreases below a certain limit.

The micro-switches use hysteresis, so the activation force is always higher than the deactivation force. Moreover, the quick movement of the metallic strip produces the typical clicking sound. When the strips close, the contacts render continuity.

The battery voltage present at one contact point is transferred to the other contact point. Once the contact points are closed, the LED starts glowing.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a device for a brake motor in an assembly line for checking, displaying and adjusting the change in brake-rotor or brake-disc thickness, the device comprises:

(a) an air-gap checking and displaying device, and

(b) an air-gap adjusting arrangement;

wherein a predetermined air-gap is pre-set between the brake-rotor or brake-disc and the coil housing by means of a micro-switch, actual air-gap displayed by means of an indicating device and subsequently the deviating air-gap is adjusted by means of an air-gap adjustment arrangement for effective motor braking operation.

Typically, the brake motor applies brake on the assembly line conveyor and a brake rotor shaft rotating about an axis for mounting the rotating brake rotor arrangement, the arrangement further comprises:

- brake motor end shield;
- armature plate;
- brake disc with an original thickness t;
- coil housing;
- hub mounted on the brake rotor shaft;
- electromagnetic coil;
- a plurality of springs;
- brake rotor shaft rotating about brake rotor axis;
- stationary disc,
- metallic dampening plate provided between the stationary disc and the coil housing and integrated therewith for pushing the brake plate uniformly;
- a plurality of fixing screws provided on the motor end shield;
- a plurality of internally threaded setting bolts for tightening and loosening the corresponding surrounding the respective fixing screws;

wherein coil housing 120 also accommodates a coil 124 and a plurality of springs 126 for applying brake by energization of the coil 124 to generate electromagnetic field 130 for brake-motor operation as and when required.

Typically, the stationary disc moves closer to the brake disc with the decrease in thickness of the brake-disc, thereby increasing the length of the travel of the stationary disc to increase the pre-set air gap.
Typically, the air-gap checking and displaying device is a battery operated unit placed in between the brake disc mounted on brake rotor shaft and the stationary disc and comprises:

- at least one base for protecting and mounting the micro-switch;

- DC battery for supplying electric current to the circuit;

- at least one pre-set spring loaded switch;

- at least one lever made of a metallic strip which is supported by the spring; and

- at least one light emitting diode (LED);

wherein the metallic strip lever closes and touches the spring loaded switch, the contacts inside the switch complete the circuit and by closure of the contact points, the LED glows to indicate the increased brake rotor air-gap.

Typically, the stiff metallic strip lever is actuated by external force to quickly flip for making contact with the switch button to complete the electrical in order to glow the LED to indicate an increased air-gap with respect to the pre-set limit thereof.

Typically, after readjustment of the air-gap to a pre-set limit, the stiff metallic strip lever flips back to its original position, thereby discontinues current supply to the LED to indicate the return to pre-set air-gap by opening the circuit.

Typically, the battery is a DC battery.

In accordance with the present invention, there is provided a method for displaying the change in air-gap between the armature plate and coil housing, wherein the metallic strip quickly flips when a predefined force is applied on it and flips back with a high speed, when the force decreases below a predefined limit, thereby, when the strip closes and touches the spring loaded switch, the contacts inside the switch completes the electrical circuit and the LED glows to indicate the actuated condition of the micro-switch indicating the increased brake rotor air-gap.

In accordance with the present invention, there is provided a method for resetting the air-gap by using the device for a brake motor in an assembly line as claimed in anyone of the claims 1 to 4, wherein the plurality of hollow setting bolts are used for precisely adjusting air-gap, the method comprises the steps of:

(i) Loosening the fixing screws by attaching the brake rotor assembly to the motor end-shield by approximately half a turn;

(ii) Loosening the brake rotor assembly from the motor end shield by rotating the threaded hollow setting bolts surrounding the fixing screws and turning counter clockwise into the brake coil housing;

(iii) turning the fixing screws by a required amount as a function of the required air-gap decrease, until the desired nominal or pre-set air gap for obtaining effective brake-rotor operation, as measured by using the appropriate feeler gauge;

(iv) turning the fixing screws clockwise to facilitate the movement of the brake coil housing towards the metallic anchor plate for reducing the air gap accordingly;

(v) re-securing the brake coil housing firmly against the motor end shield by rotating the hollow setting bolts turning clockwise or moving out of the brake coil housing;

(vi) tightening the fixing screws by appropriate torque;

(vii) re-checking and measuring the air gap at multiple locations for checking appropriate spacing;

(viii) repeating the preceding method steps as required, until the nominal air gap is uniform and consistent all around the brake rotor assembly; and

(ix) finally, checking the air gap in the brake rotor assembly by placing a feeler gage between the metallic anchor plate and the brake coil housing.

In accordance with the present invention, there is also provided a method for resetting the air-gap by using the device for a brake motor in an assembly line as claimed in anyone of the claims 1 to 4, wherein the plurality of hollow setting bolts are used for precisely adjusting air-gap, the method comprises the steps of:

(i) Loosening the fixing screws by attaching the brake rotor assembly to the motor end-shield by approximately half a turn;

(ii) Loosening the brake rotor assembly from the motor end shield by rotating the threaded hollow setting bolts surrounding the fixing screws and turning counter clockwise into the brake coil housing;

(iii) turning the fixing screws by a required amount as a function of the required air-gap increase, until the desired nominal or pre-set air gap for obtaining effective brake-rotor operation, as measured by using the appropriate feeler gauge;

(iv) turning the fixing screws counter-clockwise to facilitate the movement of the brake coil housing away from the metallic anchor plate for increasing the air gap;

(v) re-securing the brake coil housing firmly against the motor end shield by rotating the hollow setting bolts turning counter clockwise or moving into the brake coil housing;

(vi) tightening the fixing screws by appropriate torque;

(vii) re-checking and measuring the air gap at multiple locations for checking appropriate spacing;

(viii) repeating the preceding method steps as required, until the nominal air gap is uniform and consistent all around the brake rotor assembly; and

(ix) finally, checking the air gap in the brake rotor assembly by placing a feeler gage between the metallic anchor plate and the brake coil housing.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention will be briefly described with reference to the accompanying drawings, which include:

Figure 1 shows a cross-sectional view of a conventional brake motor arrangement with engaged brake.

Figure 1a shows a perspective view of a brake motor of Figure 1 in a de-energized state.

Figure 2 shows a cross-sectional view of a conventional brake motor arrangement with brake released.

Figure 2a shows a perspective view of a brake motor of Figure 2 in an energized state.

Figure 3 shows a cross-sectional view of the brake motor equipped with the device in accordance with the present invention.

Figure 4 shows the detailed view of the device .in accordance with the present invention

Figure 5 shows an enlarged view of the device in accordance with the present invention shown in Figure 4.

Figure 6 shows an actual view of the device in accordance with the present invention while checking the air-gap on a brake motor.

Figure 7 shows a perspective view of the device in accordance with the present invention in its normal condition, i.e. with lever not pressed.

Figure 8 shows a perspective view of the device in accordance with the present invention in its normal condition, i.e. with pressed/actuated lever.
Figure 9 shows a detailed view of the normal condition of the brake motor as represented in Figure 7, with the air gap within prescribed limits.

Figure 10 shows a detailed view of a worn out brake motor as represented in Figure 8, with the air gap being more than the prescribed limits.

Figure 11 shows a schematic detailed view of the device in accordance with the present invention.

Figure 12 shows a rear-side view of a brake motor during the air-gap checking by using a feeler gauge in the device in accordance with the present invention.

Figure 13 shows a cross-sectional view of a brake motor during the air-gap checking and subsequent setting procedure by using the device in accordance with the present invention.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS

In the following, different embodiments of the present invention will be described in more details with reference to the accompanying drawings without limiting the scope and ambit of the present invention in any way.

The present invention will be briefly described with reference to the accompanying drawings, which include:

Figure 1 shows a cross-sectional view of a conventional arrangement of the brake motor 10 with its brake engaged. It consists of an end shield 12, an armature plate 14 and a brake disc 16 is disposed therebetween. There is an air gap 18 between the armature plate 14 and the coil housing 20 of the brake motor 10 in the de-energized state thereof. The coil housing 20 is disposed about an axis X-X and a brake rotor shaft 28 carrying a hub 22 on which rotating brake disc 16 is mounted. The coil housing 20 also accommodates a coil 24 and a plurality of springs 26 for applying brake by energization of the coil 24.
Figure 1a shows a perspective view of a brake motor of Figure 1 in a de-energized state, showing only the end shield 12, springs 24 and brake disc 16.

Figure 2 shows a cross-sectional view of a conventional arrangement of the brake motor 10 with its brake released. In this state, electric current is applied in the coil 24, which generates an electromagnetic field 30 around the coil, thereby the rotating brake disc 16 with metallic armature plate 14 is pulled towards the coil housing 20 and thus, brake is released by the brake motor 10.

Figure 2a shows a perspective view of a brake motor of Figure 2 in an energized state, in which red arrows represent the direction of pull applied on the brake disc 16 due to the magnetic field 30 generated by energizing coil 24.

Figure 3 shows a cross-sectional view of the brake motor 100 equipped with the device in accordance with the present invention. This device is a battery operated unit developed and placed in between the brake disc 116 mounted on brake rotor shaft 128 rotating about axis X-X and the stationary disc 132, which is moveable along axis X-X. The lever 58 (Figure 4) of the unit is set according to the brake motor’s air gap 118. If brake disc 116 thickness decreases, the stationary disc 132 moves closer to the brake disc 116, thereby increasing the length of the travel of the stationary disc 132, which in turn results in an increased air gap 118 (Figure 9). The lever 58 is pressed by the stationary disc 132 and generates an indication of brake disc wear by means of an LED 60 (Figure 4). A dampening plate 134 is also provided between the stationary disc 132 and the brake housing 120. This dampening plate 134 is integrated with brake housing 120 for pushing the brake plate uniformly because the brake plate is circular in shape.

Figure 4 shows the detailed view of the device in accordance with the present invention. The device is configured in the form of a battery-operated micro-switch 50. It includes a base 52 for mounting the micro-switch, a battery 54, a spring loaded switch 56 and a lever 58. The micro switch 50 uses a metallic strip or lever 58 supported by the spring. The metallic strip suddenly flips when a certain force is applied on it. It also flips back with a high speed, when the force decreases below a certain limit. The micro-switch use hysteresis, so the activation force is higher than the deactivation force. The quick movement of the metal strip produces a typical clicking sound. Accordingly, when the strip closes and touches the spring loaded switch 56, the contacts inside the switch 56 give continuity and the battery voltage present at one contact point is transferred to the other contact point. Once the contact points are closed, LED 60 glows to indicate the actuated condition of the micro-switch, i.e. to indicate the increased brake rotor air-gap.

Figure 5 shows an enlarged view of the metallic strip 70 used in the device in accordance with the present invention shown in Figure 4. This metallic strip bends to make and break electrical contacts.

Figure 6 shows the actual device integrated in brake motor. We can mount the device from any position, but it should be ensured that the lever of the device touches the brake plate.

Figure 7 shows a perspective view of the device in accordance with the present invention in its normal condition, i.e. with lever not pressed or metallic strip is not making electrical contact. In this case, the brake rotor air-gap is within limits.

Figure 8 shows a perspective view of the device in accordance with the present invention in its normal condition, i.e. with pressed/actuated lever. In this condition, the metallic strip makes electrical contact and the brake rotor air-gap is increased beyond the prescribed limits, so the LED glows red. This indicates that the air-gap is required to be reset suitably to avoid any motor brake failure, which may result in an operational hazard and/or injury to personnel.

Figure 9 shows a detailed view of the normal condition of the brake motor as represented in Figure 7, having an air gap within prescribed limits. The brake disc 116 has an initial thickness t and the stationary disc 132 needs to originally travel by distance f for applying brake by means of electromagnetic attraction by the coil 124, wherein the initial air-gap is L.

Figure 10 shows a detailed view of a worn out brake motor as represented in Figure 8, with the air gap being more than the prescribed limits. Here, the brake disc 116 is shown worn out and its thickness has decreased by an amount ?, so the thickness of the brake disc 116 is now t-?t. This in turn increases the air-gap from L to L+? L. This means that the stationary disc 132 needs to move by an increased distance, i.e. by f+?f. If this increased distance is beyond the prescribed (safe) limits, then, the brake disc air-gap L should be reset suitably, so that the targeted or desired braking action of the brake motor can be achieved.

Figure 11 shows a schematic detailed view of the micro-switch 50 in accordance with the present invention. It includes a protection cover-cum-mounting base 52 for mounting the micro-switch 50, a 9V battery 54, a micro-switch spring loaded switch 56 and a metallic strip or lever 58. The micro switch 50 uses a stiff metallic strip or lever 58 supported by the spring. In the figure, the micro-switch 50 is shown in a non-contact position. However, once the spring loaded switch 56 is actuated by any external forces via the lever 58, the LED 60 will glow to indicate the actuated micro-switch, i.e. an increased brake rotor air-gap.

Figure 12 shows a rear side view of a brake rotor after removing the fan shroud. The air-gap checking is done by using a feeler gauge 200. The fixing screw 136 and stator bolt 142 and the DC brake 150 are also shown for this purpose.

Figure 13 shows a cross-sectional view of a brake motor while checking the air-gap and subsequent setting procedure by using the device in accordance with the present invention. The figure shows the air-gap 118 existing between the armature plate 114 and coil housing 120. The motor end shield 112 is provided with a plurality of setting bolts 138 which are configured as hollow screws with internal threads for tightening and loosening the corresponding fixing screws 136 therein. A metallic anchor plate 134 is disposed between the armature plate 114 and the brake rotor 140. Inset detail A shows the details of the loosening of the fixing screw 136 and inset detail B shows the metallic anchor plate 134 between the armature plate 114 and brake rotor 140.
The procedure for resetting the air-gap 118 is described as under:

(i) Loosen the fixing screws 136 attaching the brake rotor assembly 140 to the motor end-shield 112 by approximately half a turn.

(ii) If required, the brake rotor assembly 140 may be slightly loosened from the motor end shield 112 by turning the threaded setting bolts 138 surrounding the fixing screws 136 counter clockwise into the brake coil housing 120.

(iii) Depending on whether or not the air gap 118 needs to be decreased or increased; turn the fixing screws 136 by a required amount until the desired nominal air gap is obtained, as measured by using the appropriate feeler gauge.

(iv) Turning the fixing screws 136 clockwise facilitates the movement of the brake coil housing 120 towards the metallic anchor plate 134 and thereby reducing the air gap 118 accordingly.

(v) Whereas, turning the fixing screws 136 counter-clockwise facilitates the movement of the brake coil housing 120 away from the metallic anchor plate 134 and thereby increases the air gap 118.

(vi) If the setting bolts 138 (hollow screws) are adjusted as suggested in step (ii) above, re-secure the brake coil housing 120 firmly against the motor end shield 112 by turning the setting bolts 138 (hollow screws) clockwise, i.e. out of the brake coil housing.

(vii) Subsequently, tighten the fixing screws 136 by appropriate torque.

(viii) Re-checking and measuring the air gap 118 at multiple locations for checking appropriate spacing.

(ix) Repeating the steps as required until the desired nominal air gap 118 is uniform and consistent all around the brake rotor assembly 140.
Here, the air gap 118 in the brake rotor assembly 140 is checked by placing a feeler gage between the metallic anchor plate 134 and the brake coil housing 120.

WORKING OF THE INVENTION:

A battery operated unit developed & placed in between Stationary disc & brake disc. The lever of the unit set according to brake rotor air gap. If Brake disc thickness decreases, the stationary disc moves closer to brake disc; thus increases the length of the travel of stationary disc which results in the increasing in air gap. The Lever is being pressed by the stationary disc and generates an indication by glowing LED.

TECHNICAL ADVANTAGES AND ECONOMIC SIGNIFICANCE

The device and method for checking the brake rotor/liner air-gap in a motor brake configured in accordance with the present invention has the following advantages:

• Simultaneously indicates the air gap as well as brake disk thickness.
• Compact, low-cost and light-weight due to less number of components.
• Easily indicates online the change in air gap and brake disc thickness.
• Can be interlocked with the equipment.
• Can be integrated in the equipment via PLC.
• Can be equipped with an alarm on HMI or stopping of motors after actuation.
• Can be easily mounted on any surface.
• Offers a safer operation being battery-operated.
• Any available personnel can integrate the unit.
• Being a wireless unit, its easy installation possible on the brake motors.
• Maintenance-free and reliable.
• Makes first time detection possible.
• Offers flexibility in design.
• Reduces operator’s fatigue, thereby offers safer working condition.
• Enables zero-breakdown time, thereby improves machining uptime.
• Can be integrated with supervisory control and data acquisition (SCADA) system.
• Can be deployed in all brake motors across any group of machines.
• Rechargeable battery with charger can be integrated in this device to eliminate low battery voltage issue

Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, shall be understood to implies including a described element, integer or method step, or group of elements, integers or method steps, however, does not imply excluding any other element, integer or step, or group of elements, integers or method steps.

The use of the expression “a”, “at least” or “at least one” shall imply using one or more elements or ingredients or quantities, as used in the embodiment of the disclosure in order to achieve one or more of the intended objects or results of the present invention.

The exemplary embodiments described in this specification are intended merely to provide an understanding of various manners in which this embodiment may be used and to further enable the skilled person in the relevant art to practice this invention.

Although, only the preferred embodiments have been described herein, the skilled person in the art would readily recognize to apply these embodiments with any modification possible within the spirit and scope of the present invention as described in this specification.

Therefore, innumerable changes, variations, modifications, alterations may be made and/or integrations in terms of materials and method used may be devised to configure, manufacture and assemble various constituents, components, subassemblies and assemblies according to their size, shapes, orientations and interrelationships.

The description provided herein is purely by way of example and illustration. The various features and advantageous details are explained with reference to this non-limiting embodiment in the above description in accordance with the present invention. The descriptions of well-known components and manufacturing and processing techniques are consciously omitted in this specification, so as not to unnecessarily obscure the specification.

While considerable emphasis has been placed on the specific features of the preferred embodiment described here, it will be appreciated that many additional features can be added and that many changes can be made in the preferred embodiments without departing from the principles of the invention. These and other changes in the preferred embodiment of the invention will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.