SNAP-ENGAGING MOUNTING PLATE

Abstract: An apparatus (10) configured to facilitate mounting a first device (42) to a second device (63) where the first device (42) has a plurality of first apertures (46, 48) and the second device (63) has a plurality of second apertures (66, 67). The apparatus (10) includes a substantially planar base member (16) and a plurality of post members (12, 14) affixed to the base member (16) at a plurality of attachment loci. Each post member (12, 14) is substantially in register with a first aperture (46, 48) and with a second aperture (66, 67) when the first device (42), the second device (63), and the apparatus (46, 48, 66, 67) are in a mounting orientation. Each post member (12, 14) includes a tab member (28, 40) and a mounting aperture (18, 30) which traverses the post member (12, 14). For each post member (12, 14) and each first aperture (46, 48), the post member (12, 14) is configured to flex appropriately so that the tab member (28, 40) deflects from an initial position to pass through the first aperture (46, 48) when the post member (12, 14) is urged into the first aperture (46, 48). The tab member (28, 40) returns to the initial position when the post member (12, 14) passes a predetermined distance into the first aperture (46, 48) to captively retain the first device (42) intermediate the tab member (28, 40) and the base member (16). Each first aperture (46, 48) is substantially coaxial with one of the second apertures (66, 67) and substantially coaxial with one of the mounting apertures (18, 30) when in the mounting orientation.

Description: SNAP-ENGAGINQ MOUNTING PLATE TECHNICAL FIELD The present invention is generally related to an apparatus for mounting a subunit to a host unit in assembling a device. More particularly, the present invention relates to a mounting apparatus to facilitate mounting a first device to a second device. The mounting apparatus snap-engages one of the devices and provides mounting apertures for through-fastener mounting of the first device to the second device with the snap-engaged mounting apparatus intermediate the first device and the second device. BACKGROUND OF THE INVENTION Snap-engaging structures are found in various environments. For example, U.S. Patent No. 4,841,100, of June 20, 1989, to Ignasiak for "Expanding Surface Mount Compatible Retainer Post", discloses an expandable retainer post for use with printed circuit boards employing surface mount technology intended to be attached to a host board. The Ignasiak device, however, does not provide a mounting aperture through his snap-engaging structure to facilitate mounting with a through-hole fastener. U.S. Patent No. 5,365,408, of November 15, 1994, to Apitz for "Chassis with a Movable Attachment Element Affixed Thereto", discloses a chassis with attachment elements which cannot be separated from the chassis, with an attaching device for carrying and attaching components or chassis elements. In one embodiment, Apitz discloses a column-shaped attachment element for attaching a plate- shaped component using a hot-molded retaining head. If the retaining head must be removed during servicing, or if it breaks off, a self-tapping screw may be screwed into a central bore in the column-shaped attachment element as a repair element to affix the subchassis to the original chassis in the same manner as the original retaining head. However, Apitz does not disclose employment of a snap- engaging apparatus with a through-aperture to facilitate mounting a subassembly to a host assembly. Another known method of attaching a printed circuit board to a host device is to heat stake a mounting plate to the printed circuit board to provide the requisite stand-off spacing between the printed circuit board and the host device. There is a need for an inexpensive and reliable apparatus to facilitate mounting a first device, such as a printed circuit board, to a second device in a manner facilitating mounting by a through-hole fastener. It is particularly desirable that such a mounting apparatus be configured to provide a predetermined stand-off distance between the first device and the host device. SUMMARY OF THE INVENTION The present invention is an apparatus configured to facilitate mounting a first device to a second device where the first device has a plurality of first apertures traversing the first device at a plurality of first loci. The second device has a plurality of second apertures at a plurality of second loci. Each respective second aperture is proportioned to engage a fastener. The apparatus comprises a substantially planar base member and a plurality of post members affixed to the base member at a plurality of attachment loci. Each respective post member is substantially in register with one respective first aperture and substantially in register with one respective second aperture when the first device, the second device, and the apparatus are in a mounting orientation. Each respective post member includes a tab member and a mounting aperture, which mounting aperture traverses the post member. For each respective post member and each respective first aperture, the post member is configured to flex appropriately so that the tab member deflects from an initial position to pass through the first aperture when the post member is urged into the first aperture. The tab member returns to the initial position when the post member passes a predetermined distance into the first aperture to captively retain the first device intermediate the tab member and the base member. Each first aperture is substantially coaxial with one of the second apertures and substantially coaxial with one of the mounting apertures when in the mounting orientation. The fastener may be inserted through the coaxial apertures to mount the first device to the second device. It is, therefore, an object of the present invention to provide an apparatus configured to facilitate mounting a first device to a second device which provides an easy and reliable connection between the apparatus and the first device. It is a further object of the present invention to provide an apparatus configured to facilitate mounting a first device to a second device which facilitates effecting such mounting by through-hole mounting. Yet a further object of the present invention is to provide an apparatus configured to facilitate mounting a first device to a second device which establishes a predetermined stand-off distance intermediate the first device and the second device when in a mounted orientation. Further advantages and features of the present invention will be apparent from the following specification and claims when considered in connection with the accompanying drawings illustrating in the preferred embodiment of the invention. BRIEF DESCRIPTION OF THE DRAWINGS Figure l is a plan view of the preferred embodiment of the present invention. Figure 2 is a plan view of details of a selected post member of the apparatus illustrated in Figure 1. Figure 3 is a plan view of a printed circuit board with the preferred embodiment of the present invention engaged therewith. Figure 4 is a side view of a printed circuit board poised for engagement with the apparatus illustrated in Figure 1. Figure 5 is a side view of a printed circuit board engaged with the apparatus illustrated in Figure 1, with the apparatus secured to a host device. Figure 6 is a section drawing of an alternate embodiment of a post member for use with the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Figure 1 is a plan view of the preferred embodiment of the present invention. In Figure 1, an apparatus 10 is illustrated having a pair of posts 12, 14 depending from a base member 16. Preferably, posts 12, 14 are integrally formed with base member 16 and depend substantially perpendicular from base member 16 in the same direction from base member 16. Base member 16 is preferably a substantially planar member. Post 12 has a central aperture 18 surrounded by a wall 20. A buttress 22 and a buttress 24 are preferably integrally formed with post 12, depend from wall 20, and terminate at a position below the upper limits of wall 20 (as shall be illustrated in subsequent drawings). The respective upper limits 23, 25 of buttresses 22, 24 are substantially coplanar in a plane generally parallel with base member 16. A shelf 26 is also integrally formed with post 12 and terminates in an upper limit 27 which is substantially coplanar with upper limits 23, 25 of buttresses 22, 24. A generally wedge-shaped tab 28 is further integrally formed with post 12 and depends from wall 20. A lower limit 29 of tab 28 (to be illustrated in greater detail in subsequent drawings) terminates in a plane substantially parallel with base member 16 and displaced a predetermined distance above the plane which contains upper limits 23, 25 of buttresses 22, 24 and upper limit 27 of shelf 26. Post 14 is similarly configured with a central aperture 30 surrounded by a wall 32. Buttresses 34, 36 and a shelf 38 are integrally formed with post 14. Buttresses 34, 36 terminate at upper limits 35, 37 and shelf 38 terminates at an upper limit 39. Upper limits 35, 37, 39 lie substantially in a plane generally parallel with base member 16. Further, upper limits 35, 37, 39 are substantially coplanar with upper limits 23, 25, 27 of buttresses 22, 24 and shelf 26. A generally wedge-shaped tab 40 is also integrally formed with post 14 and terminates in a generally planar lower limit 41 (to be illustrated in greater detail in subsequent drawings) . Lower limit 41 lies substantially in a plane displaced above the plane containing upper limits 23, 25, 35, 37 of buttresses 22, 24, 34, 36 and upper limits 27, 39 of shelves 26, 38. Further, lower limit 41 of tab 40 is generally coplanar with lower limit 29 of tab 28. In order to facilitate understanding the present invention, like elements will be indicated using like reference numerals in the various drawings. Figure 2 is a plan view of details of a selected post member of the apparatus illustrated in Figure 1. In Figure 2, post 14 is illustrated as depending from substantially planar base member 16. Buttresses 34, 36 and shelf 38 are integrally formed with post 14. Post 14 has a central aperture 30 surrounded by a wall 32. A tab 40 is also integrally formed with post 14. Buttresses 34, 36 terminate in upper limits 35, 37. Shelf 38 terminates in upper limit 39, which is substantially coplanar with upper limits 35, 37. Tab 40 terminates in lower limit 41, which is displaced above upper limits 35, 37, 39. Figure 3 is a plan view of a printed circuit board with the preferred embodiment of the present invention engaged therewith. In Figure 3, a printed circuit board 42 is illustrated (details of circuit traces on printed circuit board 42 are omitted for simplicity) . Printed circuit board 42 includes a plurality of electrical terminals 44 which are configured for connection to various predetermined loci in the printed circuit borne upon printed circuit board 42 (not shown in detail in Figure 3) . Printed circuit board 42 is traversed by apertures 46, 48. In the top plan view of Figure 3, apparatus 10 is hidden below (or behind) printed circuit board 42. Apparatus 10 has been fully inserted into apertures 46, 48, thereby engaging apparatus 10 with printed circuit board 42. That is, post 12 has been inserted through aperture 48 appropriately that tab 28 rests its lower limit 29 on the top side 43 of printed circuit board 42. Upper limit 23 of buttress 22, upper limit 25 of buttress 24 (not visible in Figure 3) , and upper limit 27 of shelf 26 (not visible in Figure 3) are disposed on the lower side 45 of printed circuit board 42. Printed circuit board 42 is captively retained intermediate lower limit 29 of tab 28 on top side 43 and upper limits 23, 25, 27 of buttresses 22, 24 and shelf 26 on lower side 45. The gap established between the plane containing upper limits 23, 25, 27 of buttresses 22, 24 and shelf 26 and the plane containing lower limit 29 of tab 28 are spaced apart a distance substantially equal to or slightly greater than the thickness of printed circuit board 42 in the vicinity of aperture 48. Post 14 is similarly disposed within aperture 46 of printed circuit board 42. Post 14 is oriented with lower limit 41 of tab 40 on top side 43 of printed circuit board 42. Upper limits 35, 37, 39 of buttresses 34, 36 (not visible in Figure 3) and shelf 38 (not visible in Figure 3) are disposed on lower side 45 of printed circuit board 42. Thus, printed circuit board 42 is captively retained between lower limit 41 of tab 40 and upper limits 35, 37, 39 of buttresses 34, 36 and shelf 38. The plane containing upper limits 35, 37, 39 of buttresses 34, 36 and shelf 38 is displaced from the plane containing lower limit 41 of tab 40 a distance substantially equal to or slightly greater than the thickness of printed circuit board 42 in the vicinity of aperture 46. Figure 4 is a side view of a printed circuit board poised for engagement with the apparatus illustrated in Figure 1. In Figure 4, printed circuit board 42 is illustrated poised above apparatus 10. Post 12 is generally perpendicular with and integrally formed with base member 16. Post 12 includes wall 20 (which surrounds central aperture 18, not visible in Figure 4) . Integrally formed buttresses 22, 24 depend from wall 20. Shelf 26 is also integrally formed with post 12 and is disposed beneath integrally formed, generally wedged-shaped tab 28. Upper limits 23, 25, 27 of buttresses 22, 24 and shelf 26 are generally coplanar and are displaced a distance "d" from lower limit 29 of wedge-shaped tab 28. Distance "d" is preferably substantially equal to thickness "t" of printed circuit board 42, or slightly larger than thickness "t". Similarly, post 14 depends generally vertically from base member 16 and is preferably integrally formed with base member 16. Shelf 38 and buttresses 34, 36 (not visible in Figure 4) are integrally formed with wall 32 of post 14 and depend from wall 32. Upper limits 35, 37, 39 of buttresses 34, 36 and shelf 38 are preferably coplanar with upper limits 23, 25, 27 of buttresses 22, 24 and shelf 26 and are disposed below lower limit 41 of tab 40 a distance "d". Wedge-shaped tab 40 is also preferably integrally formed with post 14 and depends from wall 32. Figure 5 is a side view of a printed circuit board 42 engaged with the apparatus 10 in Figure 1, with the apparatus 10 secured to a host device 63. That is, Figure 5 is a side view of the assembly 10, 42 illustrated in the plan view of Figure 3, shown mounted to the host device 63. To change the orientation of printed circuit board 42 with respect to apparatus 10 from the respective positions illustrated in Figure 4 to the respective positions illustrated in Figure 5, a user must urge apparatus 10 and printed circuit board 42 together. Such urging must be appropriate to insert post 14 within aperture 46 (Figure 3) and to insert post 12 within aperture 48 of printed circuit board 42. By such urging wedge-shaped tab 40 engages an edge of aperture 46, and wedge-shaped tab 28 engages an edge of aperture 48. Further urging together of printed circuit board 42 and apparatus 10 deflects tab 40 with respect to aperture 46 and deflects tab 28 with respect to aperture 48 appropriately to facilitate passage of post 14 through aperture 46 and passage of post 28 through aperture 48. Once posts 12, 14 are sufficiently urged into their respective apertures 46, 48, tabs 40, 28 return to their initial positions at which they were situated before deflection. In such manner, appropriately aligned urging together of printed circuit board 42 and apparatus 10 changes the relative positions of circuit board 42 and apparatus 10 from the orientation illustrated in Figure 4 (poised for engagement) to the positions illustrated in Figures 3, 5 (engaged). In actuality, the flexing which facilitates passing of tabs 40, 28 through apertures 46, 48 occurs along the length of each post 12, 14, including flexing in the vicinity of tabs 40, 28. Such full-length flexing is accommodated by the elongated shape of apertures 46, 48, which is most clearly seen in Figure 3. When engaged with apparatus 10, printed circuit board 42 is captively retained intermediate lower limit 41 of tab 40 and upper limits 35, 37, 39 of buttresses 34, 36 (buttress 36 is not visible in Figures 4, 5) and shelf 38. Further, printed circuit board 42 is also captively retained intermediate lower limit 29 of tab 28 and upper limits 23, 25, 27 of buttresses 22, 24 and shelf 26. As seen most clearly in Figure 3, in this assembled orientation, apertures 18, 30 provide through-hole access through posts 12, 14, whereby the assembly comprising printed circuit board 42 engaged with apparatus 10 (as illustrated in Figures 3, 5) may be mounted to host device 63 (as shown in Figure 5) using through-hole fasteners 68, 65 through apertures 18, 30 to engage the host device 63 in appropriate mating registered apertures 66, 67. Such through-hole fastening may be effected by a threaded fastener, a rivet fastener, a force-fit pin fastener, a christmas-tree fastener, or other through-hole fasteners known in the art. Figure 6 is a section drawing of an alternate embodiment of a post member for use with the present invention. In Figure 6, a post 50 is integrally formed with a base member 52. An aperture 54 traverses post 50 and is surrounded and defined by a wall 56. Integrally formed with and depending from a first side of wall 56 is a generally wedge-shaped tab 58. Integrally formed with and depending substantially from wall 56 substantially opposite on post 50 from wedge-shaped tab 58 is a buttress 60. Buttress 60 terminates in an upper limit 61. Upper limit 61 lies in a plane 62. Wedge-shaped tab 58 terminates in a lower limit 59. Lower limit 59 lies in a plane 64. Planes 62, 64 are separated by a distance "d" which is preferably substantially equal to or slightly greater than the thickness of a printed circuit board (not shown in Figure 6) anticipated to be employed with an apparatus employing post 50. The operation of post 50 during installation with respect to a printed circuit board having appropriate apertures therethrough is substantially the same as described above in connection with engagement of apparatus 10 with printed circuit board 42. Post 50 is less complex than posts 12, 14 and presents fewer complications for its manufacture by molding, such as fewer buttresses and no shelf. Post 50 therefore provides a practical alternate embodiment for a post for use with the present invention. It is to be understood that, while the detailed drawings and the specific examples given describe the preferred embodiments of the invention, they are for the purpose of illustration only, that the apparatus of the invention is not limited to the precise details and conditions disclosed, and that various changes may be made therein without departing from the spirit of the invention which is defined by the following claims.

Claims: I claim: 1. An apparatus (10) configured to facilitate mounting a first device (42) to a second device (63) , the first device (42) having a plurality of first apertures (46, 48) traversing the first device (42) at a plurality of first loci, the second device (63) having a plurality of second apertures (66, 67) at a plurality of second loci, each respective second aperture (66, 67) being proportioned to engage a fastener (65, 68) , the apparatus (10) characterized by: a substantially planar base member (16) ; and a plurality of post members (12, 14) affixed to the base member (16) at a plurality of attachment loci, each post member (12, 14) substantially in register with one respective first aperture (46, 48) and substantially in register with one respective second aperture (66, 67) when the first device (42) , the second device (63) , and the apparatus (10) are in a mounting orientation; further characterized by each post member (12, 14) including a respective tab member (28, 40) and a respective mounting aperture (18, 30) , the respective mounting aperture (18, 30) traversing the respective post member (12, 14), further characterized in that for each respective post member (12, 14) and each respective first aperture (46, 48), the respective post member (12, 14) is configured to flex appropriately so that the respective tab member (28, 40) deflects from an initial position to pass through the respective first aperture (46, 48) when the respective post member (12, 14) is urged into the respective first aperture (46, 48) , the respective tab member (28, 40) returning to the initial position when the respective post member (12, 14) passes a predetermined distance into the respective first aperture (46, 48) to captively retain the first device (42) intermediate the respective tab member (28, 40) and the base member (16), each respective first aperture (46, 48) being substantially coaxial with one respective second aperture (66, 67) and substantially coaxial with one respective mounting aperture (18, 30) in the mounting orientation, whereby the respective fastener (65, 68) may be inserted through the respective coaxial apertures (30, 46, 67) and (18, 48, 66) to mount the first device (42) to the second device (63) . 2. The apparatus (10) of Claim 1, further characterized in that the respective post members (12, 14) are integrally formed with the base member (16) . 3. The apparatus (10) of Claim 2, further characterized in that the respective post members (12, 14) protrude substantially perpendicularly from the same side of base member (16) . 4. The apparatus (10) of Claim 3, further characterized in that each mounting aperture (18, 30) is centrally located within the respective post member (12, 14). 5. The apparatus (10) of Claim 4, further characterized in that each post member (12, 14) flexes along the entire length of the respective post member (12, 14) as the respective post member (12, 14) is urged into the respective first aperture (46, 48) . 6. The apparatus (10) of Claim 1, further characterized in that each tab member (28, 40) is generally wedge-shaped having a lower limit (29, 41) facing toward the base member (16) . 7. The apparatus (10) of Claim 6, further characterized by a plurality of buttresses (22, 24, 34, 36) integrally formed with each respective post member (12, 14), each buttress (22, 24, 34, 36) extending from the base member (16) to an upper limit (23, 25, 35, 37) facing away from the base member (16) , each upper limit spaced a fixed distance (d) from the respective lower limit (29, 41) and located a predetermined standoff distance from the base member (16) . 8. The apparatus (10) of Claim 7, further characterized in that the distance (d) is such that the first device (44) is clasped between the upper limits (23, 25, 35, 37) and the lower limits (29, 41) in the mounting orientation. 9. The apparatus (10) of Claim 7, further characterized in that the upper limits (23, 25, 35, 37) lie substantially in a first plane (62) generally parallel with the base member (16), and the lower limits (29, 41) lie substantially in a second plane (64) generally parallel with the base member (16) . 10. A circuit board assembly comprising a circuit board (42) mounted to a host device (63) , characterized in that: the circuit board (42) is secured to the host device (63) by the apparatus (10) of claim 1, and the apparatus (10) is secured to the host device (63) by the fastener (65, 68), wherein the fastener (65, 68) is a screw fastener extending through the respective coaxial apertures (30, 46, 66), (18, 48, 67) and threadedly secured in the respective coaxial second aperture (66, 67) of the host device (63) to secure the circuit board (42) at a predetermined standoff distance from the host device (63) .

Inventors: SKARIVODA EDWIN L, SKARIVODA, EDWIN, L.
Applicants: PARAGON ELECTRIC CO INC, PARAGON ELECTRIC COMPANY, INC.
Application year: 1996
Main classification: H05K7
IPC codes: H05K7