US 2232605 A
Description (OCR text may contain errors)
Feb.- 18, 1941. w. I. HoLME FLASHLIGHT Original Filed Jan. '9, 1934 INVENTOR WILL/AM l. HOLMES Patented Feb. 18, 1941 UNITED STATES PATENT OFFICE Substitute of application Serial No. 705,846, Januany 9, 1934. This application January 18, 1939,
Serial No. 251,651
This application is a substitute for application Serial No. 705,846, filed January 9, 1934, by William 1. Holmes.
This invention relates to portable flashlights or lanterns and, more particularly, to devices of this general type in which a spring motor is employed to operate a generator of electric energy, which energy is utilized to light an electric bulb.
It is the object of this invention (to provide a flashlight of the character described which will include novel assemblages of elements, and parts of novel construction, whereby a device of improved construction and operation is provided. One such novel feature is found in the provision of a resilient connection between the driving elements of the device and the generator portion. Another novel feature is found in the combined brake and governor assembly which is provided. A still further feature is the provision of belt drive means in the power transmission means, such drive means being novel in devices of this type. A still further novel element provided by the invention is a generator means of new and improved design by virtue of which greatly improved operation is achieved.
Other-objects and features of novelty of the invention will be made apparent by reference to the following specification and the accompanying drawing, it being clearly understood, however,
that such specification and drawing are only illustrative of the invention, and impose no limitation thereon not found in the appended claim.
Referring to the accompanying drawing, in which similar reference numerals refer to like parts.
Fig. 1 is a longitudinal sectional view through a flashlight formed in a manner according to the present invention;
Fig. 2 is a sectional view taken on the line 4 2-4 of Fig. 1; and
Fig. 3 is a perspective view showing a generator formed according to the invention.
In Figs. 1 and 2 of the drawing, there is disclosed a flashlight structure formed according 45 to the present invention and comprising two cylindrical, registering, open-ended, co-axial casing members 5 and B, the forward end of the rear casing member Ii being provided with an outwardly-struck, annular flange within which .the
50 rear end of the forward casing member 5 is fitted. The rear casing member may be rotated with respect to the forward casing member and interiorly thereof has fixed thereto a shaft 9 which extends in axial relation throughout the length of 55 the rear casing section. Disposed within the rear casing section and mounted on the shaft 9 for rotation with respect thereto is a spring barrel III having a convolute spring 8 therein, the outer end of the spring being attached to the barrel ill and the inner end thereof being attached to the shaft 9. The forward end of the barrel Ill is closed by a plate, and an internal ring gear I6 is attached to the inner periphery of the barrel at the forward end thereof and externally of the plate. A supporting partition I3 is fixed 1Q to the rear end of the forward casing 5 and closes the same, and the forward end of the shaft 9 is journaled in this partition, as illustrated at l2 in the drawing. A ratchet wheel I to is mounted on the forward extremity of 15 the shaft 9 and is engaged by a pawl I5 which is pivotally mounted on the partition l3,
Means are provided by the invention for transmitting power stored in the spring 8 to a generator device, to be described hereinafter, and 20 such means comprise a power transmitting assembly arranged adjacent the rear end of the forward casing member 5. Such assembly comprises a pinion gear 11 which meshes with the internal ring gear 15 and which is rotatably 25 mounted in the plate 13 and has attached to the shaft thereof a large pulley III. A resilient belt I9 is trained over the pulley l8 and over a smaller pulley 20, to the shaft of which is connected a larger pulley 2|. A resilient belt 22 is trained 30 over (the pulley 2| and over a smaller pulley 23 which is connected to the rear end of a shaft 24 which extends throughout the greater part of the length of the forward casing 5 and is coaxial therewith. 35
The shaft 24 is journaled in bushings 58 which are carried by spaced pole pieces 40, 4| which are supported within the forward casing section 5 by spaced spiders 42, 43 and which D le pieces form part of a generator which will be described fully hereinafter.
Means are provided by the invention for controlling the speed of rotation of the shaft 24 and, when desired, for stopping such rotation entirely. Such means comprise a disk 25 which 45 is slidably keyed to the shaft 24 adjacent the rear end thereof and which is provided with a grooved hub .33 which is engaged by the forked end of a shifting member 32, having an operating knob or button connected thereto and arranged exteriorly of the casing 5 in order to provide manually operable means for shifting the disk 25 with respect to the shaft 24. Pivotally mounted on one face of the disk are two levers 21, the pivotal supports of which are arranged diametrically opposite to each other. Mounted on the outer side of the free extremity of each of the levers and extending radially of the casing member is a brake member 2!. Springs 8| connect the free end of each of the levers to the pivotal support of the other lever and serve to normally maintain the brake members out of engagement with a conical brake ring I! which is mounted on the interior of the casing wall. The parts are so arranged that movement of the shifting member I2 in one direction causes the brake members to engage the conical braking ring, thereby acting, through the disk to prevent rotation of the shaft 24. Movement of the shifting member 32 in the opposite direction releases the braking members from the braking ring, and in this position the levers 21 and brake members 2| act as a governor, being operable outwardly by centrifugal force against the springs ll upon increase of the speed of rotation of shaft II above a pre-determined limit, to cause the brake members 28 to engage the braking ring II to thereby retard the speed of the shaft. The resilient connection of the brake shoes to the disk 25 insures that the parts will be stopped without shock.
Mounted within the forward casing member 5 is a generator device which comprises rotatable magnetic means carried by shaft 24 and fixed coil members carried by the casing 5. The generator is of generally cylindrical, elongated construction in order to iit within the limited size and corresponding shape of the casing. Such elongation and reduction in diameter are accomplished by employing longitudinally extending permanent bar magnets to supply the magnetic field, these being mounted to rotate about pole pieces carrying low resistance windings of novel construction. These permanent bar magnets are illustrated at 35 and comprise bars of arcuate cross-section, supported intermediate their ends on spaced discs or spiders I. which are connected by a spacing sleeve 31 which is keyed or otherwise fixed on shaft 24. To form this into a rigid structure, the discs are notched at spaced points about their peripheries in order to receive the magnet bars and the bars are notched in their opposite edges as at 38 in order to receive portions of the discs. Such received portions of the discs may be swaged or upset to effectively attach the parts rigidly together.
The adjacent magnets are arranged oppositely poled, as indicated by the N and S symbols, and the polar projections are preferably equal in number and correspond in spacing, all as illustrated in Fig. 3- Thus in the positions of registration of the magnets with the poles of the pole pieces, maximum flux conditions will prevail, because of the short and efllcient magnetic paths which will exist between unlike poles of adjacent magnets through the intervening arms of the cores.
The pole pieces 40 are preferably of laminated construction and may be of Maltese-cross shape having widened pole tips which are curved to correspond to the arcuate cross-section of the surrounding magnet bars, thus providing a compact and eflicient structure. As illustrated, the bushings 58 which support the shaft 24 may be formed as tubular rivets and, as such, may be arranged to rigidly hold the laminations of the pole pieces together.
The windings are applied to the arms of the cores or pole pieces as continuous windings extending in zig-zag fashion between successive poles, that is, from back to front through one opening between pole pieces, as at 4|, across the front of one pole at 40, back between that and the next pole as at ll, across the back of that next pole at 48, forward between that and the adjoining pole at 4!, across the front of the third pole at II, back between the third and fourth poles at II, and then across the back of the fourth pole at, 52 and continuing thence in the same order. The windings of the two cores are alternated as indicated, that is, the front windings of one core are opposed to the back windings of the other and the two are connected in series as at It. At one end, the combined windings are suitably grounded as indicated at 54, and the other, insulated end may be directly connected to one of the lamp terminals 55, as indicated at 58. The connection I! between the coils on the two cores may be laid in a groove I! which may be pressed in the side of the casing.
The cores may be wound by a special machine carrying. the wire through the openings between pole pieces in alternate directions around opposite sides of adjoining pole pieces, or the coils may be form-wound and then placed in the openings, extending as indicated around only three sides of each pole. By thus omitting one of the inactive sides of each pole winding instead of completely encircling each pole, as is usual, considerable wire is saved and resistance and objectionable inductive and counter electromotive forces are reduced. The electrical efficiency thus gained, together with the magnetic eillciency resulting from the use of straight bar magnets in completely closed magnetic circuits with the pole pieces, permits the use of a generator of the small size required for a suitable flashlight, but capable of providing suflicient current for entirely satisfactory flashlight use. Another important result is that excessive rotor speed is not required. A 400 to 1 speed ratio is practical with the rotor turning in the range of 900 to 1200 R. P. M. This relatively low speed for a generator of this type materially increases the period of useful illumination secured from a spring of given power and enables a single spring to be employed.
It has been found that, due to the effectiveness of the magnetic coupling of the generator structure disclosed, the rotor will not always immediately start when the brake is released. To overcome such possible hesitance in starting and to cause the device to start under the power of the spring motor, booster means are provided in the form of a spring 59, which is interposed between separated sections of the generator shaft and which is capable of storing sufllcient energy to overcome the normal attraction which the magnets have for the pole tips. This spring therefore provides suflicient energy to start the motor, when the driving spring is wound, at the instant when the brake is relased. The spring serves the additional function of providing a resilient coupling between the driving and driven assemblies for absorbing starting and stopping shocks and for cushioning and silencing the parts. The separated sections of the shaft which are coupled by the spring 59 are shown as held in alignment by a telescopic joint, illustrated at 60. This angularly yieldable end portion of the rotor shaft may carry the last gear element of the driving train, as is illustrated.
In the operation of the described device, the
parts are held from rotation by engagement of the braking members'28 with the conical braking ring 29. In this condition of the parts, the rear casing section 8 may be rotated with respect to the forward casing section 5, it being apparent that the spring barrel ID will be held against rotation with the casing section 6 because of the braking effect between the mem-- bers 28 and the ring 28 which is transmitted through disc 25, shaft 24, the power transmission assembly, pinion I1 and internal ring gear i8. Shaft 8 will be rotated with casing section 8 and the spring 8 will therefore be wound.
If it is desired to operate the flashlight the brake members 28 are moved out of engagement with the ring 28 and the energy stored in the spring 8 is thereupon caused to rotate the barrel l8 and internal ring gear l8, pinion l1 and speed multiplying power transmitting means l8, i8,
20, 2|, 22, 28 The shaft 24 will be caused to rotate, thereby moving the bar magnets 35 over the faces of the coils, thereby inducing currents in the coils which are supplied to the bulb which provides asource of light. So long as the speed of rotation of the shaft 24 is below a predetermined limit, springs II will hold the arms 21 and brake members 28 out of engagement with the conical ring 28. If the speed of rotation increases above. such predetermined limit. however, the force of the springs II will be overcome and the arms 21 will be moved outwardly by centrifugal force, therefore moving the braking elements into engagement with the conical ring 28 and retarding the speed of rotation of the shaft and the attached generator element. v'I'he rotation of the shaft may be stopped entirely by operating the member 34 to cause the disc 28, and the braking elements 28 which are carried there- 4 by, to move rearwardly of the casing and into engagement with the braking ring 28.
It will be seen that when the rotation of the shaft 24 and the attached magnet bars is stopped the force of the spring 8 will tend to place the spring 58, which connects the two sections of the shaft 24, under tension. When the braking elenients 28 are released from the ring 29 in order to start the operation of the flashlight the energy stored in spring 58 in the manner described will overcome any reluctance of the shaft 24 to rotate, and thereby provides a booster efiect which insures that the rotatable elements of the generator will be causedto operate when desired. The reluctance of the shaft 24 to rotate may be due to magnetic coupling between the magnets 35 and the fixed coils and it has been found that'the provision of the spring 59 is very -advantageous in overcoming this effect.
In the present application I have described one embodiment of my invention but it will be apparent to those skilled in the art that further v of the casing, permanent bar magnets extending longitudinally of the casing between said poles,
v means for eilecting rotation of said bar magnets,
current generating windings on said pole pieces, said windings extending in opposite directions about three sides only of adjoining poles and disposed oppositely on opposite pole pieces, the bar magnets in adjoining relation to said pole pieces being oppositely poled with respect thereto.
WILLIAM I. HOLMES.