# US 4,398,684 A · Connecting apparatus for a powerplant

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- Number: US 4,398,684 A
- Document ID: US4398684A
- Status: Granted
- Kind: A
- Application number: 06/252,153
- Filed: 1981-04-08
- Granted: 1983-08-16
- Earliest claimed: 1981-04-08
- Assignees: Redro, Inc.
- Inventors: Dennis Von Ruden
- Web page: https://patentgrep.com/patent/US4398684A

## CPC

- B64C 31/028: Hang-glider-type aircraft; Microlight-type aircraft
- B64D 27/00: Arrangement or mounting of power plants in aircraft; Aircraft characterised by the type or position of power plants
- Y02T 50/40: Weight reduction
- B64C: AEROPLANES; HELICOPTERS
- B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A connecting apparatus (16) for attaching a propeller or fan (14) to an engine (12) is disclosed. A connecting apparatus (16) includes a centrifugal clutch device (48) and drive and driven gears (40, 78) for reducing the speed of propeller (14) relative to engine (12). These elements are contained within a lubricant-filled housing comprised of housing (38) and spider bracket (34). Spider bracket (34) includes two pairs of vibration-dampening first and second mountings (140). First mountings (140) more stiffly resist engine vibration than second mountings (142), thereby dynamically balancing the powerplant with respect to the structural frame (20).

## Claims

### Claim 1

A connecting apparatus for an engine mounted to a structural frame, said engine for driving a rotary load, said engine having vibratory forces causing a greater torque in one direction than in a direction opposite therefrom, said apparatus comprising:
dynamically balanced means for isolating from said frame vibrations from said engine, said isolating means including a plurality of vibration dampening first mountings for more stiffly resisting engine vibration and a plurality of vibration dampening second mountings for less stiffly resisting engine vibrations, said first mountings being located rotationally advanced in the direction of greater vibratory force from said second mountings; and
speed sensitive means for releasably coupling said engine to said rotary load.

### Claim 2

The combination comprising:
a two-cycle engine having a drive shaft, said engine operating to produce vibratory forces causing a greater torque in one direction than in a direction opposite therefrom;
a structural frame for mounting said engine thereto;
a plurality of vibration dampening first mountings for more stiffly resisting engine vibrations;
a plurality of vibration dampening second mountings for less stiffly resisting engine vibrations, said first mountings being located relative to said second mountings rotationally advanced about the torque axis in the direction of greater vibratory force;
a bracket attached to said engine, said bracket having said first and second mountings secured thereto;
means for attaching said first and second mountings to said frame;
a rotary load; and
means for coupling said drive shaft to said rotary load.

### Claim 3

In an ultralight aircraft having a structural frame, a connecting apparatus for a powerplant, said powerplant including an engine having a drive shaft, said engine for driving a propellor, said connecting apparatus comprising:
a bracket attached to said engine, said bracket having a plurality of apertures;
a plurality of vibration dampening first mountings for more stiffly resisting engine vibrations;
a plurality of vibration dampening second mountings for less stiffly resisting engine vibrations, said first and second mountings being fastened within said apertures, said first mountings being located relative to said second mountings rotationally advanced about the vibratory torque axis in the direction of greater vibratory force;
means for attaching said first and second mountings to said frame;
a drive gear slideably mounted about said drive shaft;
a cylindrical shell axially spaced from and fixedly attached to said drive gear;
centrifugal clutch means, attached to said drive shaft, for operably transmitting power from said drive shaft to said shell;
a driven gear attached to a driven shaft for ultimately driving said propellor, said driven gear being driven by said drive element;
a housing, comprised partially of said bracket, for enclosing said drive and driven gears, said shell and said centrifugal clutch means; and
lubricant contained in said housing for continuously bathing said drive and driven gears, said shell and said centrifugal clutch means.

### Claim 4 (depends on 3)

An apparatus in accordance with claim 3 wherein said vibration dampening first and second mountings are comprised of a pair of concentric cylindrical shells with rubber bonded therebetween.

### Claim 5 (depends on 4)

An apparatus in accordance with claim 4 wherein the rubber in said first mountings has approximately twice the resistance to shear force as the rubber in said second mountings.