US3747975A

US3747975A - Fastener

Info

Publication number: US3747975A
Application number: US00196375A
Authority: US
Inventors: Gregor E Mc
Original assignee: UOP LLC
Current assignee: PTC Aerospace Inc
Priority date: 1971-11-08
Filing date: 1971-11-08
Publication date: 1973-07-24
Anticipated expiration: 1990-07-24

Abstract

Turn type fastener for seat-back tray table is assembled to a blind hole in the tray bottom surface and is locked thereto against unauthorized axial movement by a snap type fastening means located partially on the turn type fastener shaft and partially in a bearing member in the hole. The turnable fastener is rotatable into locking engagement with an opening in the seat back and is formed with outwardly conveying gripping portions which permit the fastener to be easily manually rotated but render it difficult to apply an outward pulling force to it. Although the fastener can be pried out of its bearing near its pivot shaft when replacement is necessary, a pulling force applied at the end of its radial handle will merely cause the pivot shaft to bind against its bearing.

Description

United States Patent [191 July 24, 1973 McGregor 1 FASTENER [75] Inventor: Eugene R. McGregor, Morris, Conn.

[73] Assignee: Universal Oil Products Company, Des Plaines, Ill. [22] Filed: Nov. 8, 1971 [21] Appl. No; 196,375

[52] U.S. Cl. 297/191, 292/202 [51] Int. Cl. A47c 7/62, EOSc 3/04 [58] Field of Search 297/191; 292/202, 292/353; 287/53; 16/114 [56] v vReferences Cited UNITED STATES PATENTS 2,769,221 11/1956 Maiman 24/216 434,295 8/1890 Richardi 292/353 1,652,548 12/1927' Wensel 292/202 1,718,661 6/1929 Nightingale 292/202 1,777,494 10/1930 Johnson 292/202 2,409,822 10/1946 Allen 292/202 2,619,395 11/1952 Kent .l 297/191 3,135,542 6/1964 Wilkinson 292/204 Primary ExaminerBernard A. Gelak Attorney-James R. Hoatson, Jr. et a1.

[57] ABSTRACT Turn type fastener for seat-back tray table is assembled to a blind hole in the tray bottom surface and is locked thereto against unauthorized axial movement by a snap type fastening means located partially on the turn type fastener shaft and partially in a bearing member in the hole. The turnable fastener is rotatable into locking engagement with an opening in the seat back and is formed with outwardly conveying gripping portions which permit'the fastener to be easily manually rotated but render it difficult to apply an outward pulling force to it. Although the fastener can be pried out of its bearing near its pivot shaft when replacement is necessary, a pulling force applied at the end of its radial handle will merely cause the pivot shaft to bind against its bearing.

6 Claims, 4 Drawing Figures Patented July 24, 1973 3,747,975

Figure FASTENER BACKGROUND OF THE INVENTION aseat' back andwhichare actuable from the bottom sideof a tray are known to the prior art. For example,

0'; s. Pat. Nos. 2,098,426; 2,619,395 and 2,963,078 each show such a latch. Another common type of tray table latch comprises a turn button-attached to the seat back which is adapted to be rotated into 'a position overlying the table in its stored position. Yet another type of latch comprises-a spring loaded ball in the tray edgewhich isheld by a detent in a tray frame member. "Many of the prior art latches" have their operating handle exposedso. as to present the. possibility of injury latching elements are held in a precise relationship relative to each other. A majority of theprior-art latches require expensive assembly and disassembly operations whey they are installed or replaced.

SUMMARY It is an object of the presen t invention toIprovide a fastener or latch which .will provide effective latching of atray table to a seat ,whilefbeing economical to manufacture, simple to install, recessedfor reducing the risk of injury,,and shaped so that a latch can be easily removed andreplacedwhen brokenbut cannotbe easily removed by a seat occupant.

These and other objects are obtained by the present invention wherein a tray table latching member is assembled to the table by merely pressing it into a blind hole in the bottom surfaceof the table. Mounted within the blind hole between the table surfaces is a bearing member which is inserted when the table is formed. The bearing member includes a detent portion, such as a spring fastener, which retains a detent such as an undercut groove formed at the inner end of a pivot shaft on the latching member. Two features of the latching member function to prevent the latching member being removed by a .seat occupant. Firstly, the operating handle, which also performs the latching function, extends radially outwardly from its pivot shaft. By making the pivot shaft diameter very close to that of the bearing, an axial pulling of the latch at'its end where it extends over the edge of the tray will tend to bend the pivot shaft and force it into a binding relationship with the bearing surface. Secondly, the handle is provided with outwardly converging sides which effectively prevent a seat occupant from obtaining a grip on the handle sufficient to pull it from its mount. Should the latch break or need replacementfor another reason, it can be pried away from its detent engagement with the bearing member by placing a tool under the latch adjacent to the pivot shaft. To reduce the possibility of injury in the event of a crash and to prevent persons from catching their clothing onthe'latch, the tray table has, its thickness reduced in the region of the latch so that the outer end of the handle is generally flush with the bottom surface of the tray.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top sectional view taken on line -ll of FIG. 2 with the pivoted latch member shown in full;

FIG. 2 is a front plan view showing the improved latch member mounted in a recess in a tray table;

FIG. 3 is a side sectional view taken on line 3-3 of FIG. 1 with the latch member shown in full; and

FIG. 4 is a view similar to FIG. I but showing a modified form of fastener.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 3, a partially rotatable latch member indicated generally at 10 is mounted on the underside of a pivoted tray table 12 which is adapted to be latched into a slot 13 formed in the back of a seat 14. Although the invention has its principal use in connection with tray tables mounted on the back of airplane seats, it could of course be used in any" situation wherein it is desired to mount a latching member in one side of a panel without disturbing the opposite side of the panel.

In FIG. 1 it can be seen that the tray table ,12 includes a top surface 15 and a bottom surface" 16 The bottom surface is recessed at 18 so that the latching member 10 will be flush with the bottom surface 16. A bearing member indicated generally at 22 which may be formed of any suitable material such as metal or plastic, is mounted within the table 12 during its manufacture.

The bearing member 22 includes an outwardly extending flanged portion 24 and an internal bearing wall portion 26. A pair of washer members 28, 30 at opposite ends of the bearing member 22 are bonded to the top and

bottom surfaces

15, 16 and provide a substantial support for the bearing member. A recess 32 formed in the bearing member 22 locates and supports a spring fastener or detent member 34 which cooperates with a grooved detent portion 40 on pivot shaft 38 which may be formed of metal or other material.

Latching member 10 is assembled to the bearing member 22 by pressing it into the bearing 22 until its enlarged diameter end portion 42 forces its way past spring fastener 34 and permits the fastener 34 to enter the grooved detent 40. A handle portion 44 on the outer end of the pivot shaft 38 includes a latching portion 46 at its end which is designed to be movable into and out of the slot 13 in seat back 14. The sides 48 of the handle portion 44 are tapered so as to converge toward each other in an outward direction. The tapered surfaces48 do not hinder a users ability to rotate the handle 44 within the limits of the recessed area 18. They do however make it most difficult to obtain a grip on the handle by which an outward pull could be exerted. The design of the handle member 44 includes yet another feature that prevents the unauthorized removal of the latching member 10 from the bearing member 22. As previously noted, the tapered surfaces 48 prevent one from obtaining a good grip on the handle 44. However, as can be seen in FIGS. 2 and 3, the latching portion 46 extends beyond the edge of the tray table where it could presumably be pulled outwardly when the tray table 12 is not latched by latch portion 46 into the slot 13. Referring to FIG. 3, it can be seen that an outward force applied parallel to the axis of shaft 38 and at point a at the end of the latch member 10 would be applied at such a considerable distance from the pivot shaft 38 that it would mainly serve to force the pivot shaft 38 into a tight binding relationship with bearing surface 26 as shown at point b. In the event that it is necessary to replace the latching member due to breakage or some other cause, a tool, such as a screwdriver, could be inserted behind the handle member 44 so as to apply a prying force at a point such as c which is close to the pivot shaft 38. In FIG. 2, the latch member 10 is shown in solid lines in its latched position and in dotted lines at 10' in its unlatched position.

The modified form of latching member 52 shown in FIG. 4 is functionally similar to the device shown in FIG. 1 but, since it requires fewer parts, is simpler and more economical to produce. The bearing member 54 extends the entire distance between the upper surface and the recessed lower surface 18 of the table 12 so as to eliminate the need for the washers 28, 30 shown in FIG. I. A detent shoulder 56 formed in the bearing member 54 cooperates with the latch member retaining surfaces 58 on the latch member pivot shaft 60 to maintain the latch member 52 within the bearing. The pivot shaft 60 is formed of a resilient material such as plastic and includes a grooved center portion 62 which defines a gap which closes as the forward cam surfaces 64 are assembled 'into the bearing member 54. The handle and latch portion 68 is identical in shape to the corresponding handle and latch portion 48 shown in FIG. 1. The detent retaining surfaces 58 can be given various angles depending on the amount of resistance against pulling out it is desired to impart to the latching member 52.

I claim as my invention:

.1. In combination, a pivoted seat back tray table and a turn-type fastener for fastening said pivoted tray table in a storage position in said seat back, said traytable having spaced apart upper and lower surfaces, said fastener comprising an elongated bearing member positioned between said surfaces and including an axially extending bearing surface accessible at one end through an opening in the lower surface of said tray table, said bearing member including a detent portion adjacent said bearing surface, a latch member including a pivot shaft portion adapted .to be engaged by said bearing surface, a detent portion on said latch member adapted to be engaged with said detent portion on said bearing member, at least one of said detent portions being resilient to permit said pivot shaft portion to be assembled in snap engagement with said bearing surface through said opening, an elongated handle portion integral with the outer end of said pivot shaft and extending radially outwardly therefrom in close overlying relation to a portion of said lower surface for the major portion of its length, said handle being selectively pivotally movable about the axis of said pivot shaft for movement of its outer extremity into and out of latching engagement with a latching portion in said seat back, said handle being formed so as to be easily manually engaged for pivotal movement into and out of said latching engagement with said seat back while resisting unauthorized attempts to axially remove said latch member from its snap engagement with said bearing member.

2. A combination in accordance with claim 1 wherein said lower surface of said tray table is recessed in the vicinity of said fastener and said handle portion has an axial length approximately equal to the depth of the recess.

3. A combination in accordance with claim 1 wherein said handle portion has outwardly converging sides which make it difficult to manually grasp the handle portion to exert an outward pulling force thereon.

4. A combination in accordance with claim 1 wherein said detent portions comprise an undercut area on one of said members and complementary projecting portion on the other member.

5. A combination in accordance with claim 4 wherein one of said detent portions comprises an expandable spring member.

6. A turn type fastener in accordance with claim 1 wherein the outer diameter of said pivot shaft portion is justslightly less than the inner diameter of said hearing surface whereby an axial pulling force applied to the outer end of said handle portion will force the pivot shaft portion against the said bearing surface so that a much greater force is required to remove the latch member from the bearing member by pulling on the end of the handle than would be required to separate the members by the application of a prying force between them at a point immediately adjacent the pivot shaft.

Claims

1. In combination, a pivoted seat back tray table and a turntype fastener for fastening said pivoted tray table in a storage position in said seat back, said tray table having spaced apart upper and lower surfaces, said fastener comprising an elongated bearing member positioned between said surfaces and including an axially extending bearing surface accessible at one end through an opening in the lower surface of said tray table, said bearing member including a detent portion adjacent said bearing surface, a latch member including a pivot shaft portion adapted to be engaged by said bearing surface, a detent portion on said latch member adapted to be engaged with said detent portion on said bearing member, at least one of said detent portions being resilient to permit said pivot shaft portion to be assembled in snap engagement with said bearing surface through said opening, an elongated handle portion integral with the outer end of said pivot shaft and extending radially outwardly therefrom in close overlying relation to a portion of said lower surface for the major portion of its length, said handle being selectively pivotally movable about the axis of said pivot shaft for movement of its outer extremity into and out of latching engagement with a latching portion in said seat back, said handle being formed so as to be easily manually engaged for pivotal movement into and out of said latching engagement with said seat back while resisting unauthorized attempts to axially remove said latch member from its snap engagement with said bearing member.

6. A turn type fastener in accordance with claim 1 wherein the outer diameter of said pivot shaft portion is just slightly less than the inner diameter of said bearing surface whereby an axial pulling force applied to the outer end of said handle portion will force the pivot shaft portion against the said bearing surface so that a much greater force is required to remove the latch member from the bearing member by pulling on the end of the handle than would be required to separate the members by the application of a prying force between them at a point immediately adjacent the pivot shaft.