US1729815A - Lead pencil - Google Patents

Description

Patented Oct. 1, 1929 UNITED stares PATENT olf-FICE BERNARD C. BECKER, OF 'YORK, PENNSYLVANIA, .ASSIGNOR TO THE YODIER PENCIL COMPANY, OF CLEVELAND, OHO, A CORPORATION OF OHIO LEAD PENCL Application led September 16, 1922. Serial No. 588,624.

This invention relates to lead pencils of the class wherein a slidable tube surrounds the lead and is adapted to recede, as the lead wears away, in response to normal pressure exerted upon the end thereof through the action of writing.

The object of this inventionI is to provide a pencil in which the slidable tube is short and therefore not so liable to become bent, and to provide means adapted tomove said short tube in unison with a push rod which forms a backing for the lead; it is important however that the tube is free to recede on the lead under the influence of normal writing pressure.

Another object is to provide a pencil in which the slidable tube cannot move in the forward direction ahead ofthe push, rod movement.

Other objects will be apparent from the following description, taken in connection with the accompanying drawings, forming 2 a part hereof, and in which similar numerals refer to similar parts throughout the several views.

Fig. 1, represents a longitudinal sectional view of the pencil, and represents one form of my invention.

Fig. 2, is a sectional view of Fig. 1,'

taken on line 2--2. Fig. 3, is a longitudinal sectional view of apencil showing a side elevation of the feeding mechanism shown in the pencil of Fig. 1, and a modified means for causing the slidable tube to move in unison with the push rod movement.

Figs. 4 and 5, show other modified means for moving the tube in unison with the push rod movement.

Fig. 6, is a sectional view of the tube 8, Fig.

5, taken on line 6-6.

With reference to Figs. 1 and 3, 7 is a tubu- 'lar casing forming a handle for the pencil.

end 12 of the casing 7 the same being adaptedto engage the groove 14. The casing 7 is split lengthwise at several places as shown at 15,.and thereby it is possible toremove the head 11 from the casing by pulling on the same in the direction indicated by arrow`16; the ends 17 will then spring outward and release the engagement of the turned-over ends 12 from the groove 14. f

Carried by the head 11 is a spindle 18 which is provided with a slot 19 anda hole 20. The crosshead 21 is adapted to slide lengthwise in the slot 19, and is provided with teeth 22 which engage with the threads 28. A push rod or lead propeller 24 is carried bythe crosshead 21 and is free to slide in the hole 20.

lt is apparent that if the head 11 is rotated relative to the casing 7, the push rod will move lengthwise in the hole 20, through the engagement of the teeth 22 with the threads With reference to Fig 1, the tube 8 is provided with a casing 25 into which are {itted the balls 26, washer 27 and spring 28. The balls 26 are adapted tok clamp upon the push rod 24 through coming in contact with the conical surface 29 and the action of spring 28 through the washer 27. lt is apparent that forward movement of the push rod, indicated by arrow 30, will carry with it the tube 8 through the slight gripping action of the balls 26; however the tube 8 cannot move forward ahead of the push rod because theballs 26 will immediately grip the push rod 24 and prevent such movement.

The gripping action of the balls 26must in no-event be sufficient to prevent inward movement of the tube 8 under the iniiuence of normal writing pressure on the end 31 thereof during the action of writin The lead 32l of course cannot move inward ecause the same is backed up by the push rod 24.

The lead 32 is prevented from moving out of the tube 8 through thev contractile spring ring 33 reference is here made to my application for patent on Lead pencil, filed July 11th, 1921, serial No. 488,788.

The operation of this pencil is as follows As writing is carried on the tube 8 gradually scribed, the tube 8 and lead 31 are caused to move forward in unison. This action may be continued until all of the lea'd is worn away. v p

For refilling this pencil, the internal mechanism, including the tube 8, is removed from the casing by pulling upon the head 11 in the direction indicated by arrow 16 and then rotating the same in the proper direction until the crosshead 21 disengages with the thread 23 at the upper end of the pencil.

During this operation the tube 8 is carried by the push rod 24. To remove the tube 8 from the push rod, you must p'ull against the sleeve 34 in the direction indicated by the arrow 30; this moves the balls 26 away from the conical surface 29 a ainst the action of the spring 28, and there y releases the gripping action of the balls 26 upon the rod 24, and said tube will freely slide off the rod.

A new lead may now be inserted in the tube 8 at either endand the pencil reassem bled through a reverse operation to that above described for disassembling.

With reference to Fig. 3, the construction and operation of this pencil is the same in every respect as that set forth for the pencil shown in Fig. 1, except for the construction of the clutching mechanism forholding the tube 8 to the push rod 24. In this construction I provide a coil spring 36, the end 37 of which is soldered or otherwise fixedto the end of the tube 8. This coil spring is adapted to normally grip the push rod 24. It is apparent that with inward movement of the tube 8 the coil spring 36 will release its gripping action on the push rod 24, sufficient to permit the tube 8 to recede upon the lea-d 32 under the inliuence of normal writing pressure applied at the end 3l thereof.. If the tube attempts to move in the opposite direction the same will pull on the end 37 of the coil spring; this will cause the coils of the spring 36 to contract and grip the push rod tighter, thereby preventing movement of the tube 8 in the outward direction. To remove the tube 8 from the rod 24, pressure is applied to the end of the coil spring at 38, sufficient to compress the spring, and thereby enlarge the coils and release the gripping action. v

With reference to Fig. 4; here the push rod 24 is crimped as shown at 40, just suicient to set up enough resistance yto lengthwise movement of the tube 8 to prevent the salne from falling out of the casing'7.

With reference to Figs.` 5 and 6; here I Having thus described my invention, what I claim, and desire to secure by United States Letters Patent is as follows:

l. In a lead pencil, the combination of a lead propelling device, means for actuating` said lead propelling device, a lead carrying tube free to recede on a lead carried thereby through the influence of normal writing pressure, and frictional means through which a resistance to lengthwise movement is effected between said tube and said lead propelling deV vice, said frictional means being sufficiently.A yielding to permit said tube to recede through the iniuence of normal writing pressure.

2. In a lead pencil, the combination of a lead propelling device, a push rod forming part of said lead propelling device, means for actuating said lead propelling device, a lead carrying tube free to recede on a lead carried thereby through the influence of normal writing pressure, and a gripping device carried by said tube and adapted to effect a resistance to movement between asaid tube and said push rod, said gripping device being sufficient y yielding to permit said tube to recede through the Writing pressure.

3. In a lead pencil, the combination of a' 'lead propelling device, a push rod forming part of said lead propelling device, means for actuating said lead propelling device, a

lead carrying'tube free to recede on a lead carried thereby through the influence of normal writing pressure, and a one-way clutch caried by said tube and adapted to grip said ro 4. In a lead pencil, the combination of a lead propelling device, means for actuating said lead propelling device, a lead carrying tube free to recede on a lead carried thereby through the iniuence of normal writing pressure, and a one-way clutch connecting said tube with said propelling device.

5. A. lead pencil comprising a casing, a push rod in said casing, means whereby said push rod may be moved lengthwise in said casing, a lead carrying tube protruding from the end of said casing, a conical casing carried by said tube, balls adapted to wedge between said conical casing and said push rod, and resilient means ada ted to force said balls into wedging condition.

6. A lead pencil comprising a casing, a push rod in said casing, means whereby said push rod may be moved lengthwise in-said casing, a lead carrying tube protruding from the end of said casing, a conical casing carried by said tube, balls adapted to Wedge between said conical casing and said push rod, resilient means adapted to force said balls into wedgng condition, and means whereby said balls may be moved out of wedging condition. In testimony whereof I afix my signature.

BERNARD C. BECKER.

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