US1240351A - Vibrating mechanism. - Google Patents

Description

F. B. LITTLE. VIBRATING MECHANISM.

. APPLICATION FILED APR. 5. 1916- I Patentedsepti 18,

2 SHEETSSHEET 1.

F. B. LITTLE.

VIBRATING MECHANISM.

APPLICATION-FILED APR. 5. 1916.

1 ,240,35 1 Patented Sept. 18, 1917.

2 SHEETS-SHEET 2.

. V) JZZJ6/UE9T' Tray/016% [2776. R? y/4 WAAAMA UNITED STATES PATENT OFFICE.

FREDERICK 13. LITTLE, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO J'. C. DEAGAN MUSICAL BELLS, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

VIBRATING MECHANISM.

Specification of Letters Patent.

Patented Sept. 18, 1917.

Application filed April 5, 1916. Serial No. 88,983.

- useful Improvement in Vibrating Mechanism, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to vibrating mechanism and is of particular service when employed in percussion musical instruments or sounding devices and has for its object the provision of an electrically operated action which is of particular use where the vibrating sound producing bodies are massive and require forceful hammer blows properly to set them into vibration, though the invention is not to be thus restricted.

One feature of the invention embraces a hammer applying electro-magnetic winding, an operating switch for establishing the circuit thereof, and a second switch operated by the hammer in its movement toward the vibrating element and actuated before the hammer strikes the vibrating element then to open the winding circuit, whereby the hammer finishes its striking movement by momentum and may be instantly withdrawn by rebounding after forcefully striking the sound producing element. The rebound from the impact is usually sufficient only to effect a portion of the restoring movement of the hammer on which account I employ a hammer restoring winding for restoring the hammer to its normal or fully withdrawn position. The hammer effects the closure of a switch in its progress toward the vibrating element to prepare the circuit of the restoring winding for complete closure when the hammer is to be withdrawn, there being another operating switch controlling the final gap in the restoring circuit. As the current employed for the hammer applying and restoring windings is comparatively heavy and as it is eration of musical instruments employing this action from a manual keyboard somewhat similar to a piano keyboard or by the use of small switches otherwise controlled and not themselves capable of properly carrying the current, I directly control the cirdesired to control the op-- cuits of the aforesaid windings by means of relay armature switches that are included in the heavy circuits while the windings of the relays are included in circuits that are controlled by the operating switches controlled by the keys of a manual keyboard or otherwise. The same switch which prepares the restoring circuit for closure and which is operated for this purpose when the hammer moves toward the vibrating element, also has a circuit controlling portion which is operated by the hammer on its return movement to establish one gap in the striking relay circuit, the switching mechanism desirably including a rocker arm carrying swltch portions upon its ends, one individual to the striking relay, and the other indiv1dual to the restoring relay, the switch parts upon the ends of the rocker arm having complemental contacts that are respectively individual to the relays.

I will explain my invention more fully by reference to the accompanying drawings showing the preferred embodiment thereof and in which Figure 1 is a view in sectional elevation of an action constructed in accordance with the invention; Fig. 2 is a plan view of the structure shown in Fig. 1; Fig.

3 is a diagram illustrating the circuit arrangement; and Fig. 4 is a view illustrative of one of the relays which I prefer to employ.

Like parts are acters of reference throughout the different figures.

The vibrating element illustrated is in the form of a tubular gong 1 having a bolt 2 passing diametrically through its upper end, this bolt being surrounded by a sleeve 3 engaging the inside of the tubular gong while the head 4 of the bolt is adapted to be struck by the hammer 5. The force with which the hammer is applied to the vibrating element, in heavy actions, is sufficient to effect a partial withdrawal of the hammer whereby the vibrations which are set up in the vibrating element are not dampened. The hammer is desirably electrically operated to effect its striking and withdrawing movements and on this account I employ a striking winding 6 and a restoring solenoids or magnets of a double magnet or indicated by similar charv compound solenoid having a common iron core 8 to be magnetically actuated by the windings, the striking coil 6 operating to move the core from its rearmost position when the hammer 5is to be applied while the restoring coil 7 operates to place the core together with the hammer adjacent thereto in a fully restored position. The hammer and the hammer stem 9 that couples the hammer with the solenoid core are desirably made of brass, the hammer and its stein being coupled by a pin 10 that is downwardly projected to be in actuating relation to the intermediately pivoted rocker or switch arm 11 which carries, at its ends, contact portions 12 and 13 that are alternately placed in the path of reciprocal movement of the pin whereby the switch arm is caused to assume one or the other of two alternative positions. In one of these alternative positions of the switch arm the contact 13 engages a complemental contact 14:, this engagement occurring when the hammer has been fully withdrawn or retracted and being due to the cam action of the pin 10 upon the inner surface of the contact 12. In the other of these alternative positions of the switch arm the contact 12 engages a complemental contact 15, this engagement occurring when the hammer is in striking movement and is due to the cam action of the pin 10 upon the inner surface of the contact 13. Thus the hammer when in striking movement closes one gap 12, 15, in the master restoring circuit and in its withdrawing movement closes one gap 13, 14, in

the master striking circuit, the master circuits including relays 16 and 17 which are respectively restoring and striking relays. In the embodiment of the invention illustrated these relays are governed by key controlled switches, there being illustrated a self-restoring piano key 18 having one switch 19, 20 which is individual to the striking relay 17 and another switch 21, 22, which is individual to the restoring relay 16, these switches being master strlking and master restoring switches respectively. When the key 18 is depressed the contacts 19, 20 of the master striking switch are closed to establish a circuit traceable from one side of the common battery 23, or other source of current, through the contacts of the master striking switch, the winding of the striking relay 17, the contacts of the switch 13, 14, to the other side of the common battery. The armature switch of the relay 17 is consequently closed whereby circuit is established for the striking windingG which is traceable from one side of the common battery 23, through said winding, the armature switch of relay 17 to the other side of said battery. The magnetic core upon the hammer 5 is so positioned with respect to the coil and the coil is so wound with reference to the source of current that the hammer will be shot from the solenoid against the vibrating element and will immediately rebound to a partially withdrawn position in which the winding 6 will be ineffective to reapply the hammer even though the key 18 should happen to remain depressed, and in the striking movement the pin IOengages the back side of the contact 13 to swing the switch arm 11 to a position in which the contact 12 will engage the contact 15 to close one gap in the circuit of the restoring relay at the switch 12, 15. When the key 18 is released the spring 19 will effect its elevation or restoration to a position in which the stationary contact 22 is engaged by the spring contact 21 that is carried by the key, whereupon the remaining gap in the circuit of the restoring relay is closed, the established circuit being traceable from one side of the battery 23, through the contacts 21, 22, the winding of the restoring relay, the contacts 12, 15, the switch arm 11, to the other side of the battery. The armature of the energized restoring relav establishes a circuit for the restoring coil 7 which is traceable from one side of the battery 23, through the armature switch of the relay 1c,

the restoring coil 7, to the other side of the The restoring coil will now act 95 battery. upon the solenoid core 8 fully to withdraw the hammer and in this Withdrawing movement the pin 10 will engage the inner side of the contact 12 to separate it from its companion and effect the engagement of the contact 13 with the contact 14 whereby one gap in the master striking circuit is again closed preparatory to a new striking move ment of the hammer to be effected when the key 18 is again depressed. The windings (i and 7 are respectivelylow and higherwound. A buffer cushion 24 is provided at the rear of the solenoid core to be engaged thereby when the hammer is fully withdrawn, the cushion absorbing the blow so that the hammer will not rebound from the position to which it is restored. The striking winding 1' is desirably iron clad, there being a shell 25 of cast iron disposed about it. The restoring winding 7 is also desirably iron clad, at least partially, there being illustrated a yoke 26 of strip iron which is anchored to the shell 25 and at the bight of which there is disposed the cushion24. The magnet structure is desirably mounted upon a base 27 having slots 28 receiving the stems of bolts 29. IV hen the bolts are loosened the hammer structure may be adjusted with reference to the vibrating element 1 whereaftcr the bolts may be tightened to fix the adjustment. I preferably employ adjusting means which resides in a bolt 30 having threaded connection with a stationary bracket 31 and in suitable connection with an car 32 projecting upwardly from the whose winding surrounds a magnetic core 33 terminating in an armature 34, this core carrying a pusher block 35 of insulating material. Whenever a relay is energized its core is moved inwardly to cause the pusher block 35 to push the contact carrier 36 against the force of a coiled spring 37 the carrier 36 being pushed far enough to force the spring contacts 38 into engagement with the contact plate 39 whereby the circuit controlled by the relay is established. The contact carrier 36 also carries a carbon contact 40 which is brought into engagement with the carbon contact 41 carried by a spring 42 mounted upon the contact 39. When the energized relay is deenergized the spring 37 withdraws the contact carrier, the contact 38 leaving the contact 39 before the contact 40 leaves the contact 41, the sparking therefore occurring at the latter contacts so as to preserve the contacts 38 and 39.

WVhile I have herein shown and particularly described the preferred embodiment of my invention I do not wish to be limited to the precise details of construction shown as changes may readily be made without departing from the spirit of my i'nvention,but having thus described my invention I claim as new and desire to secure byLetters Patent the following Vibrating mechanism including a striking hammer; one magnet for effecting striking movement of the hammer; a second magnet for withdrawing the hammer; one relay having a switch controlled thereby that is in the circuit of the first ma et for opening and closing the circuit of this magnet; a second relay having a switch controlled thereby that is in the circuitlof the second magnet for opening and closin the circuit of this magnet; switching mec anism governed by the hammer and inclusive of one switch included in the circuit of the first relay and opened by the hammer when striking and closed by the hammer in withdrawing and another switch included in the circuit of the second relay and closed by the hammer when striking and opened by the hammer in withdrawing; a key provided with means for restoring it to normal position; a switch also included in the circuit of the second relay and closed by said key when in normal position and opened by the key when depressed; and a switch also included in the circuit of the first relay and closed by said key when depressed and opened when the key is restored to normal position.

In witness whereof, I hereunto subscribe my name this thirteenth day of March, A. D. 1916.

FREDERICK B. LITTLE.

Witnesses G. L. CRAGG; ETTA L. WHITE.

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