Patent Publication Number: US-3880530-A

Title: Writing utensil

Description:
United States Patent [1 1 Katz 1 Apr. 29, 1975 1 WRITING UTENSIL [75] Inventor: Otto Katz, Schwabaek. Germany [73] Assignee: A. W. Faber-Caste. Stein bei Nurnberg. Germany [22] Filed: Aug. 14, 1973 [21] Appl. No.: 388,232  
 [30] Foreign Application Priority Data Aug. 16. 1972 Germany 2240173 [52] US. Cl 401/65: 401/93 [51] Int. Cl 843k 21/22: B42k 24/08 [58] Field of Search 401/92-94, 401/65. 67; 155/67 [56] References Cited UNITED STATES PATENTS 2.358.091 9/1944 Lovejoy 401/65 2.486.663 11/1949 Lovejoy 401/94 X FOREIGN PATENTS OR APPLICATIONS 143.542 8/1903 Germany 401/65 Primary Examiner-Lawrence Charles Attorney, Agent, or Firm-Michael S. Striker [57] ABSTRACT A barrel is provided with an elongated inner chamber having opposite open ends. and a pusher member is slidably accommodated with axial clearance in this chamber. having a portion which extends outwardly through one of these ends. The pusher member is thus slidable toward the other open end by inward pressure upon the aforementioned portion. The pusher member is formed with an axial passage which is open in direction toward the other end. and biasing means permanently opposes the sliding of the pusher member towards the other end. An abutment in the chamber is located adjacent the other end forwardly of the pusher member, and at least one elastically deformable washer. configurated either analogously to a Belleville spring or analogously to a spring washer. is accommodated in the chamber intermediate the abutment and the pusher member. The washer has a center aperture in registry with the passage of the pusher member so that a lead or the like can be received in this passage and in this aperture and extend outwardly through the other open end of the barrel.  
 8 Claims, 6 Drawing Figures A I All le/4m,  
 WRITING UTENSIL BACKGROUND OF THE INVENTION The present invention relates generally to a writing utensil, and more particularly to a mechanical pencil or ballpoint writing utensil.  
  Writing utensils of this type, for instance mechanical pencils, are known wherein the exertion of finger pressure upon a pushbutton causes the scribing member, that is either the ballpoint refill or the pencil lead, to be advanced by a certain increment. The operation of the pushbutton is opposed by a spring located in the interior of the utensil. When pressure is exerted on the pushbutton and the same is displaced inwardly into the barrel of the writing utensil, an arrangement located in the barrel engages the refill or lead and advances it through the forward open end of the barrel.  
  This type of writing utensil is extremely popular and, due to this popularity, is produced in very large quantities. One of the requirements of automated production of any type of equipment, including writing utensils of the kind here in question, is thatthe assembly of the various components be as simple as possible. In particular, it is important that to the extent possible screwthreaded connection between components be avoided, and that the general configuration of the operation of all components be as uncomplicated as possible.  
  The most widely used prior-art construction in writing utensils, particularly mechanical pencils,.wherein the lead is advanced by pushing on a button, uses a longitudinally advanceable clamp with a ring which is moved against an abutment when the button is pushed. In most instances the abutment is arranged in the tipportion of the barrel, which is a separate element that is screw-threadedly connected with the remainder of the barrel. ln addition,.the tip-portion also accommodates an elastic member which surrounds the lead. When the lead is to be advanced, the button is pushed and the slotted clamp is shifted forwardly together with the clamping ring and the lead, until the clamping ring moves against the abutment whereupon the clamp opens due to the pressure exerted by the ring; the now opened clamp can return to its starting position when the pressure on the button is released. During this return to starting position the lead is retained in thev advanced position to which it has moved, by the elastic element until such time as the clamp has returned to its starting position and has closed to re-engage the lead.  
  This type of mechanical pencil requires relatively few individual components and can be assembled without great difficulty, as long as the assembly is carried out manually. Automated assembly is, however, much more difficult to accomplish because of the screwthreaded connection required between the forward end of the barrel and the separate portion which must be connected with the same. Moreover, in this prior-art construction substantial forces act upon the clamp and the clamping ring. While these forces assure a proper clamping engagement of the lead, they require on the other hand a substantial strength of the clamp and the clamping ring which can be assured only if these components are made of metallic material. Evidently, metallic material is more expensive than synthetic plastic material which cannot be used for the aforementioned reasons. Therefore, this prior-art construction is considerably more expensive than is desirable, due to&#39;the necessity to assemble the various components manually and to make the aforementioned clamp and clamping ring of metallic material.  
 SUMMARY OF THE INVENTION It is, accordingly, a general object of the present invention to overcome the disadvantages of the prior art.  
  More particularly, it is an object of the present invention to provide an improved writing utensil which is not possessed of these disadvantages.  
  Another object of the invention is to provide such an improved writing utensil which can be produced of inexpensive materials and are therefore manufactured and sold at low cost.  
  A concomitant object of the invention is to provide such an improved writing utensil which can be manufactured very economically, and can in fact be assembled by resorting to automation techniques.  
  Another important object of the invention is to provide such an improved writing utensil having a simplified arrangement for engaging the scribing member, that is the lead or the refill, which is less expensive to produce and to install than what is known from the prior art but which, at the same time, has an efficiency which is at least equal to that known from the prior art.  
  In keeping with the above objects, and others which will become apparent hereafter, one feature of the invention resides in a writing utensil, in a combination comprising a barrel having an elongated inner chamber and opposite open ends. A pusher member is slidably accommodated in the chamber and has a portion extending outwardly through one of these ends so that the pusher member is slidable toward the other end by inward pressure upon the aforementioned portion. The pusher member has an axial passage which is open in direction toward the other end. Biasing means permanently opposes the sliding of the pusher member toward the other end. An abutment is provided in the chamber, adjacent the other end and forwardly of the pusher member. At least one elastically deformable washer is accommodatedin the chamber intermediate the abutment and the pusher member. The washer has a side facing the pusher member and a center aperture in registry with the passage of the pusher member so that an elongated rod-shaped scribing member can be received in the passage and aperture and can extend outwardly through the other end. When so received,  
 &#39; the scribing member is engaged by the inner circumferential edge face which frictionally contacts it.  
  It is advantageous if the deformable washer is configurated analogously to a spring washer, that is as a dished spring whose inner and outer circumferential surfaces are normally inclined to the axis of the aperture of the spring. If a higher elasticity and deformability is desired, then slots may be formed in the washer extending from the inner toward the outer circumferential edge face thereof.  
  The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.  
 BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an axial section through a writing utensil according to one embodiment of the invention;  
  FIG. 2 is an plan view of one of the deformable washers used in the embodiment of FIG. 1;  
  FIG. 3 is a fragmentary axial section through a writing utensil according to a further embodiment of the invention;  
  FIG. 4 is an axial section through a further washer according to the present invention;  
  FIG. 5 is an axial section analogous to FIG. 1, but illustrating an additional embodiment of the novel writing utensil which utilizes the washer of FIG. 4; and  
  FIG. 6 is a perspective view, showing a set of washers having still a different configuration in accordance with another embodiment of the invention.  
 DESCRIPTION OF THE PREFERRED EMBODIMENTS the writing utensil in FIGS. 1 and 2 has a barrel 1 provided at one of its ends (the front end) with an opening 2 through which the lead 17 can extend to the exterior. The interior of the barrel is formed as an elongated inner chamber 3 of cylindrical configuration, and inwardly adjacent the front end there is formed an abutment shoulder 4 and ribs 5 which support the lead 17.  
  The opposite end of the barrel 1, that is the righthand end in FIG. 1, is closed by a cap 6 which is provided with a guide opening 7 and with an inner annular rib 8 which can be inserted with a snap action into an outer circumferential groove 9 formed on the outer surface of the barrel 1.  
  In the illustrated embodiment, scribing-member engaging means is provided and is generally identified with reference numeral 10. This engaging means utilizes one or more (here several, which are arranged in form of two axially spaced stacks) elastically deformable washers 11 which in this embodiment are configurated as dished springs having a center aperture 12 which is bounded by an inner circumferential surface 14a. The washer 11 also has an outer circumferential surface 14, and is provided with slots 13 which extend from the inner circumferential surface 14a towards the outer circumferential surface 14. The provision of the slots 13 facilitates elastic deformation of the respective washer 11.  
  Reference to FIG. 3, which illustrates a different embodiment but wherein the configuration of the washers 11 is the same as in FIGS. 1 and 2, will show that in the normal dished configuration of the washers or springs 11 the inner circumferential surfaces 14a and the outer circumferential surfaces 14 of the respective springs l1all of which surfaces are annularare inclined to the center axis of the respective aperture 12, and hence of the lead 17.  
  A helical expansion spring 15 is located between the two packets or stacks of springs 11 in FIG. 1, and a pusher member 18 is provided having a portion 20 which extends out of the barrel 1 through the opening 7 in the cap 6, and which can be engaged by the fingers of a user to act as a pushbutton. The lead 17 is received in a central passage 19 formed in the pusher member 18, being supported in this passage as well as in the opening 2, by the ribs 5 and in the apertures 12 of the respective springs 11. Thus, the lead 17 is supported and guided over almost its entire length.  
  When the portion 20 is pushed in, that is towards the left in FIG. 1, the lead 17 can be advanced out of the opening 2 by an incremental distance which is determined by the length of the pusher member 18 and the length of a spacer sleeve 16 which surrounds the lead 17 intermediate the packages of springs 11 and within the confines of the helical expansion spring 15. It will be appreciated that when the pusher member 18 is moved towards the left in FIG. 1, the packages of springs 11 move in the same direction because they engage the lead 17, as well as the pusher member 18, until the rearward package of springs 11, that is the one farthest from the opening 2, abuts against the spacer sleeve 16. This makes it possible to select any desired incremental advancement for the lead 17 within the maximum advancement which is possible, whereupon the portion 20 is released so that the pusher member 18 can return to its starting position.  
  In the embodiment of FIG. 3 I have shown a construction wherein like reference numerals identify like components as in FIGS. 1 and 2. Here, however, there is provided an additional spacer sleeve 21 which is also located between the packages of springs 11 but which surrounds the expansion spring 15. It cooperates with an abutment portion 22 of the pusher member 18. When the lead 17 is in the advanced position, that is when it has been shifted towards the left by depressing the portion 20 (which is not shown in FIG. 3), the engagement of the springs 11 with the outer surface of the lead 17 can be terminated, simply by pushing the portion 20 further towards the left after the leading spring 1 l of the stack or package which is located at the righthand end of the spring 15, has moved into contact with the spacer sleeve 21. Further movement of the pusher member 18 towards the left, in pressure-exerting contact of the portion 22 with the springs 11, causes the springs to assume a condition of greater conicity due to their elastic deformability. In this case the outer and inner circumferential edge faces 14, 14a of the respective springs 11 will become more inclined relative to the inner circumferential surface of the barrel 1 and the outer circumferential surface of the lead 17, respectively, so that they will no longer frictionally engage the lead 17 and will thus permit the lead 17 to be shifted freely in axial direction if and as desired.  
  A further embodiment of the invention is shown in FIGS. 4 and 5, FIG. 4 showing a novel elastically deformable washer and FIG. 5 showing a writing utensil utilizing this washer. The washer shown in FIG. 4 is identified with reference numeral 25 and has a dished body 26 provided with a central aperture 27 from which slots 28 extend outwardly. In the region of the outer circumferential edge face the body 27 is provided with an outer annular collar 29 which extends towards the right in FIG. 4, and which in the installed condition of the washer 25 will face towards the pusher member 46, as is clear in FIG. 5. Cutouts 30 are formed in the collar 29, being circumferentially distributed therein.  
 At the opposite side of the body 26, that is the sidewhich in the installed condition faces the outlet opening 51 for the lead 41, there is provided an additional the region of the inner circumferential surface bounding the aperture 27. In this embodiment the helical expansion spring of FIG. 1 and FIG. 3 can be omitted, due to the effect of the collar 29 with its cutouts 30.  
  The writing utensil in FIG. 5 has the barrel 40 which accommodates the aforementioned lead 41. The cylindrical chamber in the barrel 40 is identified with reference numeral 42 and again accommodates in the region of the outlet opening 51 a plurality of supporting ribs 43 for the lead 41. A cap 44 is provided, corresponding to the cap 6 of FIG. 1. The clamping means is here identified with reference numeral 45 and is composed of a plurality of the washers 25 shown in FIG. 4. A pusher member 46 has a portion 47 extending out of the opening provided in the cap 44 and serving as a pushbutton. The pusher member 46 has an axial passage 48 in which the lead 41 is received. Unlike the pusher member 18 of FIG. 1, the pusher mem- &#39;ber 46 of FIG. 5 is stepped as shown, and its reduceddiameter portion is surrounded by a helical compression spring 50 which bears upon the shoulder formed at the step. The opposite end of the spring 50 bears upon a sleeve 49 which slidably surrounds the reduceddiameter portion of the pusher member 46, axially spaced from the larger-diameter portion thereof. In this embodiment, also, the entire axial length of the writing utensil can accommodate a lead 48 having the same length, or of course several sections of lead which together have this length. The lead is again well supported in the opening 41, by the ribs 43, the apertures 27 of the several springs 25, and the bore or passage 48.  
  A particularity in the operation of the embodiment in FIG. 5 is that here, as in the case of FIG. 3, the clamping effect of the springs 25 can be reliably negated by exerting increased pressure upon the portion 47 after the lead 41 has been advanced to the desired extent. After the advancement has terminated, and the springs 25 are in engagement, a further increased pressure upon the pressure 47 causes the force of the spring 50 to be overcome, so that the pusher member 46 shifts forwardly relative to and within the sleeve 49, until it engages the springs 25 and deflects the same into the position of greater conicity which has been described above with respect to FIG. 3. This force is transmitted from one of the springs 24 to the next via the respective collar 31. The provision of the slots 28 facilitates this deflection, that is the conversion of the respective springs 25 to more conical condition. When this condition has been achieved, the lead 41 can be freely shifted because it is no longer engaged by the springs 25, and if for instance it has moved too far out of the opening 51 it can be pushed back in to the desired extent. When the portion 47 is subsequently released the springs 25 will re-engage the lead 41.  
  Coming, finally, to the embodiment illustrated in FIG. 6 it will be seen that it is also possible to construct the engaging means 35 in form of washers having essentially the configuration of a spring lock washer. These lock washers are well known in the art, albeit in a different context, and reference is made to them only to particularly designate the configuration of the respective washers or springs 38. These again have a center aperture 36 and are provided with slots 37.  
  It will be appreciated that the present invention makes it possible to construct the barrel of the writing utensil in a very simple shape, and to insert both the respective springs and the associated pusher element in a very simple manner into the barrel before the respective cap is applied. This cap can be applied by a snapaction coupling, and no screw-threaded connection is required at all. Because of this the assembly can be carried out very readily and fully automated, if desired. The various components can be produced most inexpensively and their number is reduced to a minimum. The various springs can be produced of synthetic plastic material or of metal, for instance steel, and particularly if steel is used very high forces can be obtained which hold the lead steady against the force exerted upon it tip during writing with the utensil.  
  Moreover, and particularly in contradistinction to prior-art pushbutton operated writing utensils, the present invention makes it possible to advance the lead to a desired extent, rather to an invariable extent. The extent of advancement can be interrupted at any time within the full stroke, that is the lead can be advanced for instance by a quarter of a distance, by half the distance or the like of the total distance to which it can be advanced during a single depression of the respective pushbutton. Moreover, this can be done without having the lead return to its starting position (i.e., having it become retracted again) when the pushbutton is subsequently released, as is the case in the prior-art constructions where the lead will stay in the advanced position only if it has been advanced to the maximum extent possible during a single depressing of the pushbutton.  
  It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the type described above.  
  While the invention has been illustrated and described as embodied in a writing utensil, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.  
  Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.  
  What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:  
  1. In a writing utensil, a combination comprising a barrel having an elongated inner chamber and opposite open ends; a pusher member slidably accommodated with axial clearance in said chamber and having a portion extending outwardly through one of said ends, so that the pusher member is slidable toward the other end by inward pressure upon said portion, said pusher member having an axial passage which is open in direction toward said other end; biasing means permanently opposing the sliding of said pusher member toward said other end; an abutment in said chamber adjacent said other end and forwardly of said pusher member; and at least one elastically deformable dished spring washer accommodated in said chamber intermediate said abutment and said pusher member, said washer having a side facing said pusher member, an outer circumferential edge face, a center aperture in registry with said passage and bounded by an inner circumferential edge face both of said edge faces being normally inclined to the axis of said aperture, so that an elongated rodshaped scribing member can be received in said passage and aperture and can extend outwardly through said other end with said inner circumferential edge face frictionally engaging said scribing member. an outer annular collar projecting toward said pusher member in the region inwardly adjacent said outer circumferential edge face, and an inner annular collar projecting away from said pusher member in the region outwardly adjacent said inner circumferential edge face.  
  2. A combination as defined in claim I, wherein said washer is provided with slots extending from said inner towards said outer circumferential edge face of said spring washer.  
  3. A combination as defined in claim 1, wherein said side of said washer facing toward said pusher member is Concave.  
  4. A combination as defined in claim 1; and further comprising additional ones of said washer, similar to the first-mentioned one and axially adjacent the same so as to form with the same and with one another a stack.  
  5. A combination as defined in claim I, said biasing means being a helical spring; and further comprising a spacer sleeve slidably accommodated in said chamber between said washer and said helical spring, said spacer sleeve having a center opening in axial alignment with said aperture.  
  6. A combination as defined in claim 1, wherein said dished spring is formed with circumferentially distributed slots extending from said inner toward said outer circumferential edge face.  
  7. A combination as defined in claim 1, wherein said biasing means is a helical expansion spring surrounding said pusher member intermediate said portion and said washer; and further comprising a sleeve slidably surrounding said pusher member intermediate and bearing with its opposite ends upon said washer and said helical expansion spring.  
  8. A combination as defined in claim I, said washer being deformable from less conical into more conical condition in response to application of axial stress; and wherein the diameter of said aperture bounded by said inner circumferential edge face is substantially equal to the outer diameter of the scribing member when said washer is in said less conical condition, and is greater than said outer diameter when said washer is in said more conical condition.