GB2134690A - Gong striking mechanism - Google Patents

Abstract

A motor actuated bell includes a gong 101, an electric motor 105 mounted on a frame 106 located within the interior of the gong and having a rotatable drive shaft 104, a collar 103 eccentrically mounted on the drive shaft for rotation therewith, a cylindrical hammer 102 surrounding the outer periphery of the collar, and resilient means (e.g. coil springs) located between the collar and hammer in order to support the hammer and collar in spaced relationship and minimise impact forces on the drive shaft when the outer surface of the hammer strikes the gong. <IMAGE>

Description

SPECIFICATION Gong striking mechanism This invention relates to an electric bell of the type which is driven by a motor and adapted for use in a fire bell, an alarm bell or the like, and more particularly to a gong striking mechanism driven by a motor to strike a gong.

In a conventional electric bell as shown in Figure 1, rotationally fixed to a motor shaft is a pivoting plate 2, at one end of which a counterweight 3 is attached and at the other end of which a striking hammer 4 is arranged in a slot 5 to move forwardly and backwardly against a gong 6 during the rotation of a motor 7. The location of the striking hammer 4 varies each time it strikes the gong 6 so that the weight balance between the two ends of the pivoting plate 2 with respect to the rotary shaft 1 of the motor 7 can not attain an appropriate condition and fluctuate during the hammer striking motion.

Moreover, when the motor 7 starts to rotate and the striking hammer 4 strikes the gong 6 the relatively long plate 2 having at the both ends the counter-weight 3 and the striking hammer 4 either causes to bend the motor shaft 1 due to the large torque imparted thereon, or removes gradually away from the shaft 1 due to no provision of fixing means for fixing the shaft 1 and the plate 2. The latter case is seen when the shaft is relatively small in diameter and insusceptible of inserting a fixing means such as a pin to fix the shaft 1 and the plate 2. Therefore, the bell of the type described has such a disadvantage that the rotation of the motor 7 is not smooth and it is apt to fluctuate. Further, the shaft 1 is subjected to bending force which causes irreparable damages thereto.

in order to overcome the above disadvantage, a bell as shown in Figure 1 has been proposed employing a cam 8 fixedly attached to an axis 9 of a motor 10 and a crank rod 11 which engages the cam so as to convert a rotational motion of the motor 10 to a reciprocal motion, thereby causing a spring plate 12 to reciprocate in order to strike a gong 1 3 with a hammer 1 4 fixedly attached to the plate 12. The spring plate 12 is fixed at one end thereof to a supporting plate 1 5 and is connected at the other end thereof to the crank rod 11.

In the bell as described above, however, there exist some problems such as a plurality of assembly processes to be accomplished, expensive cost, and a difficult adjustment to get an optimum sound volume.

According to the present invention there is provided a motor actuated bell including a gong, an electric motor mounted on a frame located within the interior of the gong and having a rotatable drive shaft, a collar eccentrically mounted on the shaft for rotation therewith, a cylindrical hammer surrounding the outer periphery of the collar, and resilient means being located between the collar and hammer in order to support the hammer and collar in spaced relationship and minimise impact forces on the drive shaft when the outer surface of the hammer strikes the gong.

Reference is now made to the accompanying drawings, in which; Figures 1 and 2 are a sectional side view and a bottom view illustrating examples of a conventional motor driven type bell; Figures 3 and 4 are sectional side views each showing an embodiment of this invention: and Figures 5, 6, and 7 are sectional side views and a plan view showing a hammer and a collar between which a resilient means are arranged.

Figures 3, 4, 5, 6 and 7 illustrate an embodiment of the invention in which numeral 101 designates a gong. A supporting plate 106 is fixedly connected to the gong 101, an it receives at one end a motor 105 to the shaft 104 of which a collar 103 is fixedly attached in such a manner that it is offset from the centre of the collar 103 so as to strike a protrusion 107 with a hammer 102 once every rotation of the motor shaft. The hammer 102 having a cylindrical shape is disposed around the collar 103 keeping a predetermined space distance and also it is prevented from removing during rotation from the collar 103 by a rim integrally made at the top edge thereof. At the clearance between the collar 103 and the hammer 102, there is provided resilient means which absorbs in part a shock resulted from a striking motion of the hammer 102 against the protrusion 107.The resilient means are examplified as depicted in Figures 5, 6 and 7 in such a manner that the hammer 102 and the collar 103 are supported resiliently each other by springs 108 which are fixed at both ends to the grooves formed either in the hammer 102 or the collar 103 (Figure 5), the hammer 102 and the collar 103 are resiliently associated with each other by springs 109 which are fixed at one end thereof to the groove formed in the collar 1 03 and at the other end they are made free (Figure 6), or the hammer 102 and the collar 103 is resiliently associated with each other by employing a shock absorber such as a spring wire 110 or a plate spring which is fixed around the collar surface by an appropriate fixing means such as a bonding agent.

The operation of the gong striking mechanism thus constructed will be described.

Upon energization of the motor, its rotary shaft is rotated so that the collar 103 is urged to rotate around the shaft, thereby causing the hammer 102 to move reciprocally relative to the gong protrusion 107 in order to generate bell sounds.

Each time the hammer 102 strikes the gong protrusion 107, impact forces are exerted upon the hammer 102. Impact forces are absorbed in part in the resilient means thereby to cause no damages against the motor shaft by eliminating the possible bending force applied to the shaft.

1. A motor actuated bell including a gong, an electric motor mounted on a frame located within the interior of the gong and having a rotatable

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

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Gong striking mechanism This invention relates to an electric bell of the type which is driven by a motor and adapted for use in a fire bell, an alarm bell or the like, and more particularly to a gong striking mechanism driven by a motor to strike a gong. In a conventional electric bell as shown in Figure 1, rotationally fixed to a motor shaft is a pivoting plate 2, at one end of which a counterweight 3 is attached and at the other end of which a striking hammer 4 is arranged in a slot 5 to move forwardly and backwardly against a gong 6 during the rotation of a motor 7. The location of the striking hammer 4 varies each time it strikes the gong 6 so that the weight balance between the two ends of the pivoting plate 2 with respect to the rotary shaft 1 of the motor 7 can not attain an appropriate condition and fluctuate during the hammer striking motion. Moreover, when the motor 7 starts to rotate and the striking hammer 4 strikes the gong 6 the relatively long plate 2 having at the both ends the counter-weight 3 and the striking hammer 4 either causes to bend the motor shaft 1 due to the large torque imparted thereon, or removes gradually away from the shaft 1 due to no provision of fixing means for fixing the shaft 1 and the plate 2. The latter case is seen when the shaft is relatively small in diameter and insusceptible of inserting a fixing means such as a pin to fix the shaft 1 and the plate 2. Therefore, the bell of the type described has such a disadvantage that the rotation of the motor 7 is not smooth and it is apt to fluctuate. Further, the shaft 1 is subjected to bending force which causes irreparable damages thereto. in order to overcome the above disadvantage, a bell as shown in Figure 1 has been proposed employing a cam 8 fixedly attached to an axis 9 of a motor 10 and a crank rod 11 which engages the cam so as to convert a rotational motion of the motor 10 to a reciprocal motion, thereby causing a spring plate 12 to reciprocate in order to strike a gong 1 3 with a hammer 1 4 fixedly attached to the plate 12. The spring plate 12 is fixed at one end thereof to a supporting plate 1 5 and is connected at the other end thereof to the crank rod 11. In the bell as described above, however, there exist some problems such as a plurality of assembly processes to be accomplished, expensive cost, and a difficult adjustment to get an optimum sound volume. According to the present invention there is provided a motor actuated bell including a gong, an electric motor mounted on a frame located within the interior of the gong and having a rotatable drive shaft, a collar eccentrically mounted on the shaft for rotation therewith, a cylindrical hammer surrounding the outer periphery of the collar, and resilient means being located between the collar and hammer in order to support the hammer and collar in spaced relationship and minimise impact forces on the drive shaft when the outer surface of the hammer strikes the gong. Reference is now made to the accompanying drawings, in which; Figures 1 and 2 are a sectional side view and a bottom view illustrating examples of a conventional motor driven type bell; Figures 3 and 4 are sectional side views each showing an embodiment of this invention: and Figures 5, 6, and 7 are sectional side views and a plan view showing a hammer and a collar between which a resilient means are arranged. Figures 3, 4, 5, 6 and 7 illustrate an embodiment of the invention in which numeral 101 designates a gong. A supporting plate 106 is fixedly connected to the gong 101, an it receives at one end a motor 105 to the shaft 104 of which a collar 103 is fixedly attached in such a manner that it is offset from the centre of the collar 103 so as to strike a protrusion 107 with a hammer 102 once every rotation of the motor shaft. The hammer 102 having a cylindrical shape is disposed around the collar 103 keeping a predetermined space distance and also it is prevented from removing during rotation from the collar 103 by a rim integrally made at the top edge thereof. At the clearance between the collar 103 and the hammer 102, there is provided resilient means which absorbs in part a shock resulted from a striking motion of the hammer 102 against the protrusion 107.The resilient means are examplified as depicted in Figures 5, 6 and 7 in such a manner that the hammer 102 and the collar 103 are supported resiliently each other by springs 108 which are fixed at both ends to the grooves formed either in the hammer 102 or the collar 103 (Figure 5), the hammer 102 and the collar 103 are resiliently associated with each other by springs 109 which are fixed at one end thereof to the groove formed in the collar 1 03 and at the other end they are made free (Figure 6), or the hammer 102 and the collar 103 is resiliently associated with each other by employing a shock absorber such as a spring wire 110 or a plate spring which is fixed around the collar surface by an appropriate fixing means such as a bonding agent. The operation of the gong striking mechanism thus constructed will be described. Upon energization of the motor, its rotary shaft is rotated so that the collar 103 is urged to rotate around the shaft, thereby causing the hammer 102 to move reciprocally relative to the gong protrusion 107 in order to generate bell sounds. Each time the hammer 102 strikes the gong protrusion 107, impact forces are exerted upon the hammer 102. Impact forces are absorbed in part in the resilient means thereby to cause no damages against the motor shaft by eliminating the possible bending force applied to the shaft. CLAIMS

1. A motor actuated bell including a gong, an electric motor mounted on a frame located within the interior of the gong and having a rotatable drive shaft, a collar eccentrically mounted on the shaft for rotation therewith, a cylindrical hammer surrounding the outer periphery of the collar, and resilient means being located between the collar and hammer in order to support the hammer and collar in spaced relationship and minimise impact forces on the drive shaft when the outer surface of the hammer strikes the gong.

2. A bell according to Claim 1 wherein the resilient means comprises a plurality of coiled springs both ends of which are fixed respectively to the collar and hammer.

3. A bell according to Claim 1 wherein the resilient means comprises a plurality of coiled springs one end of which are connected to the collar and the other end of which are free.

4. A bell according to Claim 1 wherein the resilient means comprises a spring wire or ribbon fixed around the periphery of the collar.

5. A motor actuated bell substantially as described with reference to any of Figures 3 to 7 of the accompanying drawings.