Abstract:
The retaining plus is used for assembling or retaining an array of needle roller bearings in the center of a gear. The plug applies a spring force through a push ball and a wire retainer clip which separates a pair of the needle roller bearings and force the array of bearings together and against the inside diameter of the gear.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a retaining plug for assembling or retaining needle roller bearings in the centers of gears. This is achieved by applying a spring force through a push ball and a retaining wire, to separate two of the needle roller bearings and force them against each other and against the inside diameter of the gear. 
         [0003]    2. Description of the Prior Art 
         [0004]    The prior art retaining plug of  FIG. 1  included a cylindrical body having a spring biased and ball detent located in a cavity of the body midway between the ends thereof. The spring biases the ball outwardly against a pair of roller bearings. In use what happens is that the sides of the ball detent would get crushed which would prevent the ball from coming out far enough to retain the needles. Thus, after two or three uses of the prior art plug, they would tip the needle bearings and all of the needle bearings would fall out. 
         [0005]    Other devices of the prior art includes Japanese Pat. No. JP02002155963A, entitled, “Device for Preventing Fall-Off of Needle from Needle Bearing in its Assembling”, having a publication date of May 31, 2002. It discloses a device for preventing fall-off of a needle from a needle bearing in its assembling, having a construction by which even if a temporary shaft in an assembling process of the needle bearing is removed, the needle is maintained without falling off, and a permanent shaft can be inserted. 
         [0006]    Japanese Pat. No. JP358196939 A., entitled, “Method for Arranging Balls Uniformly and its Device”, was published Nov. 16, 1983. The device arranges balls uniformly by applying an axial load to an inner wheel after inserting balls between the inner and outer wheels. A needle is inserted in sequence in the gap around the balls between the inner and outer wheels thereby arranging the balls uniformly when assembling a ball bearing. 
         [0007]    U.S. Pat. No. 2,639,498 (Rookstool) entitled, “Bearing Insert Removing and applying Tool”, issued May 26, 1953, relates to a tool for removing and/or applying the bearing insert for the bearings of a shaft. 
         [0008]    U.S. Pat. No. 2,860,406 (Reichardt) entitled, “Roller Bearing Retaining Means”, issued Nov. 18, 1958 illustrates a roller assembly and another roller retention mechanism which is relatively expensive when compared with the present invention. A dummy tubular plug is employed which enters somewhat loosely inside the circular arrangement of the rollers. The plug has two radially bored holes, offset axially, and possibly circumferentially one from the other. There is a formed wire clip which must be entered inside the bore of the tubular plug and the two bent ends fitted radially outward through the bored holes. A resilient rubber-like plug is located inside the bore of the tubular plug to hold the wire clip in place. Thus, this three-piece roller retaining assembly appears to be relatively expensive to manufacture and has to be reused to be feasible. This creates additional expenses for collecting, handling, shipping, storing and cleaning the roller retention mechanism. 
         [0009]    U.S. Pat. No. 3,259,962 (Taylor) entitled, “Method of Assembling Bearing Elements, issued Jul. 12, 1966, relates to a method of assembling bearing balls or equivalent roller bearing elements between inner and outer, coaxially and radially spaced bearing members. The method includes the assembly of a circumferential series of bearing members between race surfaces, one of which is machined or fixedly formed upon a part which is journaled by the assembled bearing structure, for example, an elongated worm of a steering mechanism. The worm, in turn, is approximately sustained in a relatively fixed axial relation of its interval race surface to that of the co-acting, radially spaced race surface of a structure in which the end of the worm is axially received. 
         [0010]    U.S. Pat. No. 3,345,723 (Stilla et al.) entitled, “Dummy Pin Means and Method for Assembling Needle Bearings”, issued Oct. 10, 1967. It includes a simple form of dummy pin which may be used not only for the assembly of needle or roller bearings having a single roll set, but also for bearing arrangements involving double sets of rolls, with an axially interposed spacer sleeve or collar. The pin further can be arranged to cooperate with the spacer so that it is impossible to assemble a part without inclusion of the spacer. 
         [0011]    U.S. Pat. No. 4,166,660 (Murphy) entitled, “Roller Assembly with Roller Retention Spring”, issued Sep. 4, 1979. It discloses a folded spring which extends relatively diametrically across the circle of rollers in a roller assembly with each diametrical side pressing between two adjoining rollers to wedge these rollers apart circumferentially and thus depress all of the rollers against the wall of the bore in a “keystoning” effect with sufficient force to prevent axial movement of the rollers and to radially retain the rollers in the body. The spring may be removed from the body after shipment, preferably by a simple axial push. 
         [0012]    U.S. Pat. No. 4,596,472 (Vezirian) entitled, “Thrust Bearing and Axial Retainer System for Rotary Cone Rock Bits and Method for Assembling Same”, issued Jun. 24, 1986. It discloses a retention and thrust bearing system for retaining and locating a rotary rock cutter cone upon a journal shaft supported by a rock bit body. The cone is rotatively supported on the cooperating journal shaft by plain friction roller bearings. 
         [0013]    U.S. Pat. No. 6,568,859 (Stegmeier) entitled, “Bearing Support”, issued May 27, 2003. It relates to a rotating shaft bearing mounting structure and, in particular, to a bearing support for facilitating removal and replacement of a bearing and for supporting the rotatable shaft while the bearing is removed from the shaft. 
         [0014]    The retaining plug, according to the present invention, substantially departs from the conventional concepts and designs of the prior art, and in so doing, provides a tool primarily developed for the purpose of facilitating insertion of and for retaining the needle roller bearings in the centers of gears by the application of a spring force through the push ball of a detent and the accompanying retaining wire. This separates two of the needle rollers and force them against each other and against the inside diameter of the gear. 
       SUMMARY OF THE INVENTION 
       [0015]    In view of the disadvantages inherent with the prior art retaining plugs and tools for arranging ball bearings and devices, the present invention provides a new retaining plug developed for use in a process for retaining the needle roller bearings into the center a of gear. 
         [0016]    To attain this, a feature of the invention comprises a retaining plug having a body with a longitudinal axis and an outer surface. A longitudinal passage is located in the body at one side of the longitudinal axis and is open at one end. A slot is located in the outer surface of the body and a cavity is located in the body having an axis perpendicular to the longitudinal axis. A transverse passage is located in the body parallel to and spaced from the axis of the cavity. A spring and ball detent is located in the cavity. A wire retainer clip with a pair of ends is located in the longitudinal passage and is provided with a curved intermediate portion which extends through the slot. The ends of the retainer clip are located in the longitudinal passage and the ball of the spring and ball detent engages the curved portion of the retainer clip and biases same outwardly. 
         [0017]    Another feature of the present invention is to provide a retaining plug of the aforementioned type wherein the body is cylindrical and the longitudinal passage, cavity and transverse passage, are each of circular cross section. 
         [0018]    Still another feature of the present invention is to provide a retaining plug of the aforementioned type wherein the slot is in the form of a rectangle and through which the curved portion of the retainer clip extends. 
         [0019]    A further feature of the present invention is to provide a retaining plug of the aforementioned type wherein a retaining plug of the aforementioned type wherein the wire retainer clip is made exclusively from wire of circular cross section. 
         [0020]    A still further feature of the present invention is to provide a retaining plug of the aforementioned type wherein a cylindrical body is provided having a longitudinal center axis and an outer cylindrical surface. A pair of longitudinal passages are located in the body at opposite ends thereof at one side of the center axis. The passages are opposed to one another and each passage is open at one end thereof, with the opposite end being closed. The longitudinal passages have a common longitudinal axis which is parallel to the longitudinal center axis of the cylindrical body. 
         [0021]    Another feature of the present invention is to provide a retaining plug of the aforementioned type wherein there is a pair of slots in the cylindrical surface of the body, with the slots being longitudinally aligned and spaced apart and overlying the longitudinal passages. With such construction the cylindrical body is provided with a pair of cavities, each cavity having an axis perpendicular to the longitudinal axis with the corresponding passage. Each of the longitudinal passages has a transverse passage in the body parallel to and spaced from the axis of the corresponding cavity. 
         [0022]    Still another feature of the present invention is to provide a retaining plug of the aforementioned type wherein each cavity is provided with a spring and ball detent and a longitudinal wire retainer clip, with a pair of ends located in the corresponding longitudinal passage. Each retainer clip has an intermediate curved portion which extends through the corresponding slot in the cylindrical body. With such construction, the ends of the wire retainer clips are retained in the longitudinal passage by cylindrical roll pins which are provided in the transverse passages. 
         [0023]    There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be understood, and in order that the present contributions to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and will form the subject matter of the claims appended hereto. 
         [0024]    Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. 
         [0025]    As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for designing of other structures, methods and systems for carrying out the several purposes of the invention. It is important, therefore, that the claims be regarded as including such equivalent constructions in so far as they do not depart from the spirit and scope of the present invention. 
         [0026]    The objects and various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and its specific features and objects attained by its uses, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0027]      FIG. 1  is a fragmentary cross sectional view of a prior art tool used to retain bearings in the center of a gear. 
           [0028]      FIG. 2  is an elevational view of the novel retaining plug of the present invention. 
           [0029]      FIG. 3  is a cross sectional view taken on the line  3 - 3  of  FIG. 2 . 
           [0030]      FIG. 4  is a cross sectional view taken on the line  4 - 4  of  FIG. 3 . 
           [0031]      FIG. 5  is a fragmentary cross sectional view illustrating the novel retaining plug of the present invention being utilized for retaining the needle roller bearings in the center of a gear as a result of applying a spring force through the push ball and retaining wire to separate two of the needle rollers and force them against each other and against the inside diameter of the gear. 
           [0032]      FIG. 6  is an elevational view of the cylindrical body of the novel retaining plug. 
           [0033]      FIG. 7  is a cross sectional view taken on the line  7 - 7  of  FIG. 6 . 
           [0034]      FIG. 8  is an elevational view of another embodiment of the present invention. 
           [0035]      FIG. 9  is a cross sectional view taken on the line  9 - 9  of  FIG. 8 . 
           [0036]      FIG. 10  is a perspective view of a mechanism employing a plurality of gears, with a permanent shaft being shown in one instance of pushing and removing the temporary retaining plug of the present invention from the gear for its subsequent reuse. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0037]    Automotive manufacturers depend on needle bearing injection systems for faster and more reliable assembly. The preferred system is made by Letnan Industries, Inc. of Sterling Heights, Mich. 48314, and may include an apparatus of the type illustrated and described in U.S. Pat. No. 4,837,910, issued Jun. 13, 1989, entitled, “Method and Apparatus for Assembling Anti-Friction Bearings”. This system collects and assembles a discrete number of needle bearings in an annular array into a part such as a gear utilizing positive displacement and a serpentine track. The loose bearings are retained, as an example, by temporary steel retaining plugs while transporting to final assembly. The retaining plug of the present invention is also a temporary plug and is meant to replace the plugs now in use with the Letnan Industries&#39; needle bearing injection systems. 
         [0038]    As mentioned previously,  FIG. 1  illustrates a prior art temporary plug A, having a cavity with a spring biased ball detent B engaging a pair of needle ball bearings C forming a part of a discreet number of needle bearings C as assembled in an annular array in the center of a gear D. The ball of the detent B wears out rather rapidly and cannot effectively hold the two adjacent needle bearings apart and against the inside diameter of the gear. 
         [0039]    Referring now to the drawings, the novel temporary retaining of process plug is designated by the numeral  10 ,  FIGS. 2-4  inclusive. It consists of a generally cylindrical elongated body  12  having the ends provided with upper and lower chamfers  14  and  16 . The body  12  has a longitudinal center axis  18 . The body  12  has a longitudinal passage of circular cross section designated by the numeral  20 . The passage  20  has a longitudinal axis  22  which is parallel to the center axis  18  of the body  12 . The passage  20  enters through the top end  14  and terminates a short distance from the bottom  16  as shown in  FIG. 3 . The body  14  is provided with a slot  24  of a generally rectangular cross section. The upper and lower ends  26  and  28  of slot  24  are curved as shown in  FIG. 1 . The slot  24  intersects the longitudinal passage  20 . A transverse passage  30  having a transverse axis  32  is provided in the cylindrical body  12 . A generally centrally located cavity  34  is provided in the body  12 . The back surface  36  of the cavity  34  is closed while the front surface is opened and intersects the passage  20  as best illustrated in  FIG. 3 . 
         [0040]    The body  12  is provided with a detent  40  consisting of a spring  42  and a spherical ball  44 . In order to overcome the problems of the prior art, a wire retaining clip  50 , formed by a single piece of wire of circular cross section, is provided to cooperate with the ball  44  of the ball detent  40  as illustrated in  FIG. 3 . The wire clip  50  has a curved intermediate portion  52  which on the inside thereof has a surface  54  which seats the ball  44 . As a result, the spring  42  and the ball  44  of the detent  40  urge the wire  50  outwardly in the direction of arrow A of  FIG. 3 . With the present invention, there are provided three passages,  20 ,  30  and  34 , with the spring and ball detent  40  located in the cavity  34 . The spring wire  50  is first inserted into passage  20  through the slot  24  with the upper end  56  thereof inserted first. After the upper end  56  is inserted behind the slot  24 , then the lower end  58  of the wire  50  is inserted. The wire clip  50  is then held in place by means of the cylindrical dowel pin  59  which extends into passage  30 . With such a construction, the ball  44  seats in the curved portion  52  of the wire clip  50 . Thereafter, the wire clip  50  is locked in place by the roll pin  60  which is inserted through the passage  30  as shown in  FIG. 6 . The roll pin  60  traps the wire retainer  50  in place. 
         [0041]    The novel temporary retaining plug  10  as described in connection with  FIGS. 2-4  inclusive is illustrated in  FIG. 5  where it is employed in a needle bearing injection system of the type manufactured by Letnan Industries, Inc. The system collects and assembles a discrete number of needle bearings  60  in an annual array in a gear  62 . The loose bearings  60  are retained by the temporary retainer plug  10  when transporting the gear  62  to final assembly. The retaining plug  10  is a temporary plug and replaces the plugs now in use with the Letnan Industries needle injection systems: 
         [0042]    It should be noted that the spherical ball  44  of the retaining plug  10  does not contact the bearings  60 ; rather, the wire or clip spring  50  is urged in between the pair of adjacent needle bearings  60  as illustrated in  FIG. 5  and urges the bearings  60  against one another and against the inside diameter of the gear  62 . With this device, the ball  44  of detent  40  does not wear as rapidly as the prior art device and can effectively, with the assistance of the wire spring  50  separate the pair of adjacent bearings  60  and urge the bearings  60  against the inside surface of the gear or part  62 . 
         [0043]    The retaining plug  10  may be made in various sizes, with different diameters, lengths, and widths. Each elongated body may have anywhere from three passages and one slot, as described in connection with  FIGS. 2-4  inclusive or six passages and two slots as described in connection with  FIGS. 8 and 9 . This embodiment consists of a single body with two detents. With a retaining plug having triple detents, there would be nine passages and three slots, while a plug having quadruple detents would have twelve passage and four slots. 
         [0044]    Continuing on with  FIGS. 6 and 7 , there is illustrated a different sized body for a plug utilizing a single detent. It is slightly shorter than the body of  FIG. 3  and is approximately twice the diameter of the plug of  FIG. 3 . The body  70  contains three passages, namely a longitudinal passage  72  having a longitudinal axis  74  which is parallel to the center longitudinal axis  76  of the body  70 . It further includes a transverse passage  78  and a recess or cavity  80  which receives the spring and ball of the detent. The wall of the body  70  is provided with an elongated slot  82 . The body  80  is designed to receive a ball detent, a dowel pin, and a wire spring or clip in generally the same manner as described in  FIGS. 1-3  inclusive. 
         [0045]    A further embodiment of the present invention is illustrated in  FIGS. 8 and 9 , where the plug  90  is provided with two detents. Plug  90  contains a body  92  containing double the number of passages and slots as does the embodiment of  FIGS. 2-4  inclusive. The body  92  has a chamfered top surface  94  and a chamfered bottom surface  96 . The body  92  has a center axis  98  and a pair of longitudinal passage  100  and  102  having a common longitudinal axis  104 . The passages  100  and  102  are spaced apart near the center of the body  92 . Each passage  100 ,  102  has a transverse passage  105 ,  106 , a cavity or passage  108  and  110  and longitudinally aligned and spaced apart slots  112  and  114 . The spring and ball detents  120  and  122  are received in the corresponding cavities  108  and  110 . The ball  121 ,  123  of each detent is seated in the curved center portion  126 ,  128  of the wire clip  130  and  132 , respectively. The ball of each detent urges the curved portion of the wire clips  126 ,  128  to the right as viewed in  FIG. 9 . Dowel pins  134  and  131  traps the corresponding wire clips in their respective longitudinal passages behind the corresponding slot. The roll pins  134  and  136  trap the wire clips  130 ,  132  in place. 
         [0046]    A carrier  140  carrying a plurality of needle bearing assemblies or gears  142  are mounted in the carrier  140 . Washers  144  are placed on opposite sides of each gear  142 . A secondary process plug  146  having upper and lower detents  148  is inserted into the carrier  140  to remove the temporary retaining plug  10  from the carrier  140 . The upper and lower detents  148  retain the corresponding gears in the carrier  140 . Subsequently the assembled gear and carrier  140  are moved to a further processing operation where the carrier and gear assembly  140  is mounted on an axle, not shown. The retaining plugs  10  which are removed from the carrier  140  are subsequently re-used. 
         [0047]    With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. 
         [0048]    Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resort to, falling within the scope of the invention.