US2475750A - Model airplane starting unit - Google Patents

Description

July 12, 1949. G. H. MccoRMlcK ET AL 2,475,750

MODEL AIRPLANE STARTING UNIT Filed Nov. 3, 194'? 2 Sheets-Sheet 2 INVENTORJ. (eorge HM? format/ Thomas LMcrmz'c/ Patented July 12, 1949 MODEL AIRPLAN E STARTING UNIT George H. McCormick and Thomas L. McCormick, Rock Island, Ill.

Application November 3, 1947, Serial No. 783,678

1 Claim.

O'ur present invention relates to an improved model airplane engine starter of the type especially designed for use by model airplane enthusiasts to eliminate the diicult and troublesome task of manually winding the propeller to start the engine.

In the miniature motors used in model planes it is impossible -for proper working conditions to employ mechanical or electrical starters on the plane, and therefore we have devised the device of our invention which consists in a portable motor and battery which may be easily connected with the nose of the propeller hub to rotate the propeller and engine until it starts to fire.

In the accompanying drawings we have illustrated one complete example of the physical embodiment of our invention according to the best mode we have thus far devised, but it will be understood that various changes and alterations may be made in the exemplified structure Within the scope of the appended claim.

In the drawings:

Fig. 1 is a front elevational view of the device of our invention.

Fig. 2 is a side elevational view thereof.

Figs. 3 and 4 are end elevational views of the housing sections separated.

Fig. 5 is a sectional view at line 5-5 of Fig. 1.

Fig. 6 is a detail view of the main switch.

Fig, 7 is a diagrammatic view of the electrical circuit.

Referring now to the drawings wherein we have illustrated the present preferred embodiment of our invention we employ a housing or casing consisting of the lower section 2 and upper section 4 secured together by screws 6. The upper section 4 has a handle 8 for ease of carrying secured by screws I0 and the lower section is shaped to secure a conventional storage battery I2, having terminals I4 and IB.

A motor I8 has lugs 20 through which the screws 22 secure the motor within the upper section. The driven shaft 24 of the motor is attached in driving relation with a cylinder 26 journaled in collar 28, and the hub 38 of the cup 32 is secured by set screw 34 in the cylinder. An interior rubber liner 36 is provided in the cup, and the hub is recessed at 38 to accommodate the bolt 4I) which secures the shaft and the cylinder.

A pair of opposed brackets 42 and 44 on the motor are drilled to receive the bolts 46 and 48 on which are slidably mounted the cross arms 50 and 52 having contacts 54 and 56, the arms being resiliently spaced by spring 58.

A switch 60 is located in the upper section to open the circuit when the device is not in use and to prevent accidental operation of the motor as When the starter is being transported. A contact plate 62 is housed in insulating block 64 and engages the contact block 66 when the sections of the housing are in assembled position.

Connectors 68 and 'IIJ in bases I2 and 74 permit the use of auxiliary or booster current sources if desirable.

From the above description it will be apparent that when the switch 68 is closed, the hub of a propeller, not shown, of a model airplane may be inserted into the lined cup and pressed in, the contacts 54 and 56 will engage each other to close the circuit and the motor will drive the shaft and the cup to spin the airplane engine until it starts. Release of pressure on the cup will allow the spring to disengage the contacts and break the circuit.

Having thus fully described our invention what We claim as new and desire to secure by Letters Patent is:

A portable starter for model airplane engines comprising a casing, a source of electrical energy within said casing, a motor secured in said casing, a shaft driven by said motor, a collar on said casing in alignment with said shaft, a tubular member slidably journaled in said collar, means slidably keying said tubular member on said shaft for relative axial movement thereon, a cup-shaped member secured to said tubular member, bracket means on said rmotor, bolt means secured to said bracket means substantially parallel to said shaft, a pair of opposed cross arms slidably mounted on said bolt means, opposed contacts on said cross arms, respectively, coiled spring means between said cross arms biasing the same part whereby said contacts are separated from each other and one of said cross arms abuts said tubular member, means placing said source of energy, motor and contacts in a series circuit, whereby the propeller hub of` a model airplane may be inserted into said cup-shaped member to move the same toward said shaft to cause said contacts to close the circuit to energize said motor.

GEORGE H. MCCORMICK. THOMAS L. MCCORMICK.

REFERENCES CITED The following references are of record in the iile of this patent:

'UNITED STATES PATENTS Number Name Date 1,331,791 Wilkinson Feb. 24, 1920 1,504,766 Knipfer Aug. 12, 1924 2,855,852 Fisher Aug. 15, 1944 2,431,316 Dudley et al. Nov. 25, 1947

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