Patent Publication Number: US-3878929-A

Title: Type disc with integral coupling device

Description:
United States Patent [191 Orlens et al.  
 [ 1 Apr. 22, 1975 TYPE DISC WITH INTEGRAL COUPLING DEVICE [75] Inventors: Alfreds Orlens, Old Greenwich;  
 William W. Coville. Stamford. both of Conn.  
 [73] Assignee: Pitney-Bowes, Inc., Stamford Conn.  
 [22] Filed: Nov. 23, 1973 [21] Appl. No.1 418,291  
 [52] U.S. Cl 197/53; 197/l8 [51] Int. Cl B4lj H24 [58] Field of Search 197/18, 52, 53, 54, 6.7  
 [56] References Cited UNlTED STATES PATENTS 3.272.30l 9/l966 Craig l97/6.7 3.481.2ll l2/l969 Bottazzi l97/67 X OTHER PU BLICATlONS IBM Tech. Disclosure Bulletin, Vol. 13, No. 1. June Primary Examiner-Edgar S. Burr Assistant Examiner-R. E. Suter Attorney. Agent, 0&#34; FirmWilliam D. Soltow, .lr.; Albert W. Scribner; Robert S. Salzman [57] ABSTRACT A low cost. one piece. plastic coupling having inherent spring-like qualities for quickly connecting and disconnecting a printing disc to a printing machine. The coupling is molded of a plastic having a memory in order to provide a positive spring-biased connection. The coupling is attached or made integral with the printing disc and is operable by applying finger pressure to one end of the coupling causing two flexible extensions to bend. Securing hooks 0f the coupling can then be easily engaged to, or disengaged from. a drive shaft of the printing machine.  
 3 Claims, 6 Drawing Figures TYPE DISC WITH INTEGRAL COUPLING DEVICE This invention pertains to a flexible plastic coupling. and more particularly to a flexible coupling for quickly connecting or disconnecting a printing disc from the hub of a printing machine.  
 BACKGROUND OF THE INVENTION In printing devices of all kinds. it is highly advantageous to be able to replace worn parts. and perform maintenance with rapidity. Very often it is the small operative features. which dictate public acceptability. For example. the ease of replacing a used ribbon in a typewriter without dirtying one&#39;s hands. has been known to have greatly influenced the sale of that particular model.  
  In the case of high speed quality printing devices the ease of maintenance is a highly significant selling point. High speed quality printing generally produces a sizable degree of wear upon the parts ofthe machine. thus requiring frequent maintenance. The parts which are most frequently needing replacement in serial printers are the ribbon and printing disc. Therefore. it is desirable to be able to easily replace a printing disc. It is also desirable for an operator to have a set of easily assembled discs each having a different style or font of characters for different printing situations. such as discs having deluxe type. pica type. elite type. etc.  
  This invention seeks to provide a low cost coupling which allows for rapid assembly and replacement of a printing disc in a serial printing mechanism.  
 SUMMARY OF THE INVENTION This invention is for a one-piece flexible plastic coupling which is attached to a printing disc. and which allows the printing disc to be quickly and easily connected or disconnected from a rotative hub of a print ing machine.  
  The hub of the printing machine is provided with an abutting surface over which the coupling rides. and is allowed to snap-fit into place. The coupling comprises a center section which seats upon the hub member. From the center section. there extends to radially projecting flexible arms. The arms have a flexible springlike resiliency, which enables them to bend and flex. This inherant flexibility is due to the memory qualities of the plastic material. Materials commonly exhibiting the desired flexibility and memory are for example: acetal homopolymer. acetal copolymer. and polypropylene.  
  Each flexible arm supports a rigid flange at its outer end. The flange is disposed opposite the center section and has a finger engageable end. and a coupling. hooklike end. The hook-like ends of the rigid flange ride over-the hub abutment and snap into place. This is accomplished by means of depressing or pushing upon the finger engageable ends of the flange. so as to cause the flexible arms to bend. When the arms are made to bend, the hook-like portions of the flanges ride over the abutment of the hub. The coupling is then securely locked into place.  
  It is an object of the invention to provide an improved easily connectable and disconnectable coupling;  
  It is another object of this invention to provide a means of easily assembling or replacing a printing disc in a printing machine;  
  It is a further object of the invention to provide a coupling arrangement for a printing disc. which is of low cost. one-piece. plastic construction.  
  These and other objects of this invention will become more understandable. and will become more apparent with reference to the following detailed description. taken in conjunction with the accompanying drawings. in which:  
  FIG. 1 is a prospective view of the inventive printing and coupling assembly of this invention shown in the unassembled state;  
  FIG. 2 is a side view of one embodiment of the coupling of FIG. 1 shown being assembled;  
  FIG. 2b is a side view of the coupling of FIG. 2a shown in its assembled state;  
  FIGS. 3a through 30 are side views of a second embodiment of the coupling of FIG. 1, shown in three different stages of assembly.  
  Generally speaking. the invention is for a one-piece flexible plastic coupling which is either attached to. or integrally formed with. a printing disc. The coupling is designed to quickly connect or disconnect the printing disc to and from a rotative hub of a printing machine. The hub has an abutting surface with which the coupling is engageable. The coupling comprises a center section which seats upon the hub of the printing machine. At least one flexible arm member extends outwardly from the center section. The flexible arm has a spring-like resiliency which enables it to bend and flex in a spring-like manner. A substantially rigid flange is disposed upon the flexible arm member opposite the center section. The flange has a finger engaging end and a coupling end. The finger engaging end is adapted to receive pressure applied to it by the finger of an operator. This finger pressure causes the flexible arm member to flex and bend. The coupling end of the flange rides over the abutting surface of the hub during assembly, when the center section of the coupling is caused to be seated upon the hub. and the flexible arm is caused to bend. The printing disc locks upon the rotative hub of said printing machine after the coupling end of the flange rides over the abutting surface of the hub.  
  Now referring to FIG. I, the printing disc assembly of this invention is shown in the unassembled state. A printing disc 10 having a plurality of radially extending arms 11 is depicted. Each of the arms 11 are flexible and carry a character type 9 at their ends. A center section of the disc 10 supports a coupling illustrated generally by arrow l2. The coupling-l2 has a bore 14 which seats (arrow 13) upon a hub 15. The hub 15 is part of the drive shaft 16 of the rotative drive mechanism of a printing machine. The hub 15 also comprises a disctype flange section 17 having two notches l8 and 19. respectively. cut therein. The notches l8 and 19 receive rigid flange members 20 and 21. respectively. of the coupling 12. Coupling 22, hook-like ends of the flange members 20 and 24 ride over the abutting surfaces 23 of the notches l8 and 19 and lock on a rear surface of disc 17.  
  The flange members 20 and 21 are respectively supported upon two flexible arm members 24 and 25, as shown.  
  The coupling 12 is molded in one-piece. of a plastic material exhibiting a memory. The flexible arms 24 and 25 are molded in thin enough cross-section. so that they exhibit flexibility. and because of the memory characteristics of the plastic. will also exhibit a springlike resiliency. Therefore. if the arms 24 and 25 are caused to bend. they will flex in a spring-like manner. The flange members 20 and 21 are molded in a thicker cross-section than the arms 24 and 25, and are therefore. substantially rigid.  
  The flanges 20 and 21 each have a finger tab 26, which can be depressed (Sec FIG. 2) so as to lift the hook-like ends 22 over the abutting surfaces 23. The finger tabs 26 may also be pushed (arrow 13) towards the drive shaft 16. This will cause the inclined surface 27 of the hook-like ends 22 to advance upon abutting surfaces 23, resulting in the spreading apart of the flange members 20 and 21 about their hooked ends. This will allow the hook-like ends 22 to ride over the abutting surfaces 23 (See FIG. 3a).  
  The notches l8 and 19 are of unequal size. as are the respective matching flanges 20 and 21, and hence the printing disc 10 can be put upon the shaft 16 in only one set position.  
  FIG. 2a and 2b illustrate one embodiment of the inventive coupling. In FIG. 2a. the coupling 12 is shown being inserted upon drive shaft 16. The finger tabs 26 of the flanges 20 and 21 are depressed (arrows 28) by applying finger pressure thereto. This causes arms 24 and 25 to flex as shown. which causes hooks 22 to spread apart from each other (arrows 29). Hook-like ends 22 now have sufficient clearance to override abutting surfaces 23 of the notches l8 and 19 respectively.  
  When the coupling 12 is completely seated upon the drive shaft 16, (FIG. 2b) the finger pressure on the tabs 26 is released. This causes hook-like ends 22 to move toward each other. (arrows 30) because resilient arms 24 and 25 of the coupling will now tend to return to their unflexed condition.  
  The hook-like ends 22 will now come to rest upon the beveled surfaces 31 as shown in FIG. 2b. The coupling 12 is now locked upon drive shaft 16. The arms 24 and 25 still exert a certain amount of flexural force upon flanges 20 and 21, and hence. upon hook-like ends 22,  
 so that hook-like ends 22 tend to remain locked upon beveled surfaces 31.  
  FIGS. 3a through 30 show a second embodiment of the coupling of this inventive printing disc. As can be seen from FIG. 3a, when the coupling 12 is completely seated upon drive shaft 16, the hook-like ends 22 of the flanges 20 and 21 rest upon abutting surfaces 23. Abutting surfaces 23 in this embodiment do not contain beveled surfaces 31 as shown in FIGS. 2a and 2b.  
  In order for the coupling 12 to become locked upon shaft 16, the hook-like ends 22 must be made to ride over abutting surfaces 23, and latch behind them upon surfaces 32 as shown. Because the arms 24 and 25 are in a flexed condition when hook-like ends 22 are upon abutting surfaces 23, (FIG. 3a) the hook-like ends 22 will tend to move toward each other as they ride past surfaces 23. This will cause the hook-like ends 22 to firmly anchor upon surfaces 32, and thus. cause the coupling 12 to lock upon shaft 16.  
  The above locking condition is accomplished by causing finger pressure to be applied upon tabs 26 as shown by arrows 33 in FIG. 3a. Tabs 26 are pushed toward drive shaft 16, causing hook-like ends 22 to ride over abutting surfaces 23 as illustrated in FIG. 3b. The hook-like ends 22 will now move toward each other as shown by arrows 34, thus locking them behind surfaces 32.  
  When tabs 26 are caused to be pushed as depicted in FIG. 3a. the flexible arms 24 and 25 will be caused to flex in an opposite direction as shown in FIG. 3b. This will produce a returning force (arrows 35 of FIG. 3b)  
  upon the hook-like ends 22, causing them to seat flush upon surfaces 32 as shown by arrows 36 in FIG. 30, when pressure is no longer applied to tabs 26 as in FIG. 30.  
 Thus. the coupling 12 is caused to be readily conl() nected to drive shaft 16. In order that the coupling 12 be disconnected from shaft 16, the tabs 26 are depressed as shown by arrows 28 of FIG. 2a, and the printing disc is unseated from shaft 16 (bore 14 is lifted outwardly from the hub Thus. the coupling I5 12 is just as easily disconnected as it is connected to shaft 16.  
  The coupling can be made as a separate unit, and then attached to the center section of the printing disc, or the disc 10 and coupling 12 may be molded integrally ofa flexible plastic such as: (a) acetal homopolymer; (b) acetal copolymer; or (c) polypropylene.  
  The coupling of this print disc invention can naturally take on several different forms and modification not inconsistant with the quick connect and disconnect objectives outlined herein.  
  Therefore, it is considered that all such changes and modifications which would be obvious to the skilled practitioner be deemed to lie within those limits encompassing the invention.  
  The full spirit and scope of the invention should be interpreted with respect to the appended claims.  
 What is claimed is:  
  1. A one-piece flexible plastic coupling integrally formed with a printing disc and being operable to quickly connect or disconnect said printing disc to and from a rotative hub ofa printing machine, said hub having abutting surfaces with which said coupling is engageable. said flexible coupling comprising a center section seatable upon the hub of said printing machine. two flexible arm members extending outwardly from the center section, said flexible arm members having a spring-like resiliency which enable them to bend and flex in a spring-like manner, and a substantially rigid flange disposed upon each of said flexible arm members in juxtaposition with said center section, each said flange having a finger tab end and a coupling end, each said finger tab receiving pressure applied thereto for the purpose of causing said flexible arms to flex and bend, each said coupling end of each said flange riding over one of said abutting surfaces of said hub during assembly when said center section of said coupling is caused to be seated upon the rotative hub and the flexible arms are caused to bend. said printing disc locking upon said rotative hub of said printing machine after the coupling ends of said flanges ride over said abutting surfaces of said hub.  
  2. A printing assembly containing a quick connect and disconnect coupling, said printing disc assembly comprising:  
 a rotative drive shaft for rotatively moving a printing disc coupled thereto. said drive shaft having a hub portion and abutting surfaces upon which the printing disc is made to lock thereon; and  
 a printing disc having a plurality of flexible arms radially extending from a central disc section. each of said arms containing a character type at an outer end thereof. said printing disc having a quick con- 5 6 nect and disconnect coupling disposed within said pressure to said flange members causing the flexicentral disc section and integrally formed thereble members of said coupling to flex and allow the with, said coupling comprising two flexible memcoupling means of said flange members to lock bers each supporting a substantially rigid flange upon said abutting surfaces of said drive shaft.  
 member, said flange members each having locking 5 3. The printing disc assembly of claim 2, wherein the means for locking upon said abutting surface of locking means of each said flange member is a hook said drive shaft when said printing disc is assembled member.  
 thereto, said coupling being operative by applying