US3012805A

US3012805A - Flush latch

Info

Publication number: US3012805A
Authority: US
Inventors: Lloyd R Poe
Original assignee: Hartwell Corp
Current assignee: Hartwell Corp
Priority date: 1959-11-05
Filing date: 1959-11-05
Publication date: 1961-12-12
Anticipated expiration: 1978-12-12

Description

Pm R F Dec. 12, 1961 INVENTOR LLOYD R. POE

ATTORNEYS Filed Nov. 5, 1959 5 BY k Patented Dec. I2, 1961 s,a1z,a05 FLUSH LATCH Lloyd R. Poe, Los Angcles, Califl, assignor to Hartwell Corporation, a corporation of California Filed Nov. 5, 1959, Ser. No. 851,060 2 Claims. (Cl. 292-429) This invention relates to latches. More particularly the invention provides a novel flush type latching mechanism for securing in the closed position closure members such as engine hoods for motor vehicles and the like.

I have invented a flush type latch which, with only one operating motion of the latch mechanism simultaneously provides alignment of the closure member with respect to the cooperating understructure, draw-down of the closure member on the understructure with good mechanical advantage, and positive keeping action. My new latch is also very easy to open but will not under any ordinary conditions open of its own accord.

In addition to these principal features, and even though as a matter of convenience my new latch is provided with springs to assist in opening the latch and to bias the mechanism into locked position, breakage of these springs will not render the lock inoperable or allow the latch to open unintentionally. Even if the springs should break, the latch may be opened and closed and the only difference between its operation then and its normal operation would be that the assistance provided by operative springs would have to be provided manually.

In normal operation, the latch may be closed or opened with one hand and this operation is free and easy even though the latch is called upon to correct substantial amounts of misalignment of the closure member with respect to the understructure on which it closes.

My new latch mechanism automatically locks at the end of the closing operation and does not require a sep arate locking operation. When closed and locked the latch maintains all of the draw-down force exerted during the closing of the latch. This assures that the closure member is held tightly in place. To open the latch it is only necessary to push a button to release the operating member locking means.

According to my invention, a flush latch for a closure member, which is hinged to and constructed and arranged to close on an understructure, comprises a hook adapted to be fixed to the understructure at a location spaced from the axis of the hinge by which the closure member is connected to the understructure. The hook is provided with a portion extending outwardly from the understructure toward the closure member.

The closure member itself is provided with an aperture which is adjacent the hook member when the closure member is in the closed position. Pivotally mounted within this aperture is an operating member comprising a pair of spaced and substantially parallel mounting walls and an elongated handle portion fixed to and bridging the space between the mounting walls. The long dimension of the handle portion is substantially parallel to the walls and in the usual case the dimensions of the handle member are substantially the dimensions of the aperture in the closure member so that in the closed position the handle member will occupy substantially the entire open area of this aperture.

Means are provided for mounting the operating member in the closure member aperture for pivotal motion about an operating axis parallel to the closure member and perpendicular to the mounting walls of the operating member. A hook engaging member is mounted between the mounting walls at a position more. distant from the handle portion of the operating member than is the operating axis about which the operating member pivots. When the operating member is pivoted about the operating axis to the closed position, the handle portion is substantially flush with the closure member and the wall members extend toward the hook member mounted on the understructure. In this closed position, the hook engaging member in the operating member is in engagement with the outwardly extending portion of the hook member.

A sear engaging lip is fixed to the closure member and extends transversely of the aperture therein at a position spaced from the operating axis of the operating member. The operating member has a scar pivotally mounted between the mounting walls. The pivotal axis of the sear is perpendicular to the mounting walls and is spaced from the handle portion of the operating member. It is provided with a portion adapted to engage the lip and lock the operating member in the closed position. Means are also provided for pivoting the sear out of engagement with the lip to enable the operating member to be pivoted out of the closed position.

To enable those skilled in the art to obtain a complete understanding of my invention, the features and structural characteristics are elaborated upon in the following detailed description of a particular embodiment of the invention. In the course of this description, reference is made to the accompanying drawing in which:

FIG. 1 is a plan view of afiush type hood latch according to my invention; and

FIG. 2 is a side elevation, partly broken away, of the latch shown in FIG. 1, the operating motion of the latch being indicated in outline.

Referring now to the drawing, the latch shown is spa cifically designed as a hood latch for an automobile. In a typical installation the hood over the engine of an automobile is formed of sheet metal and some portions of the hood are essentially horizontal surfaces and other portions are vertical or substantially so. The hood is hinged to the frame or body of the car so that it may be raised from and lowered onto the understructure of the automobile around the engine. For one arrangement frequently used the hood is hinged to the understructure by one or more hinges, the axes of which are horizontal and located toward the front of the hood. In this case the back of the hood rises upon opening and lowers for closing.

A hood of this type may advantageously use a pair of my new latches located toward the back of the hood. Furthermore, one complete latch assembly would be mounted in each of the opposite side walls toward the back of the hood. Viewing the automobile from the front, one latch, arranged as in FIG. 2, is mounted in the left hand side wall of the hood and an identical latch which would appear as a mirror image of FIG. 2, is mounted in the right hand side wall of the hood. The contour of the left hand side wall of the hood with respect to the latch assembly is indicated in phantom at 1 and 2 simply to give the reader a notion of the flush appearance of the latch assembly in the closed position. For clarity the actual details of the mounting latch on the hood have been omitted, although the means for mounting the assembly will be indicated in due course.

At 3 there is indicated a portion of the fire wall o other suitably located structural member of the automobile. A hook member 4 is attached by bolts and nuts 5 and 6 to the fire wall. The hook member is formed of long and narrow strip of metal and bent at the upper end to provide the curved portion 7 which extends outwardly from the structural member on which it is mounted. For the installation suggested above, there would be one such hook member mounted on the left hand side of the automobile and one on the right hand side, the curved portions extending in opposite directions.

At a position adjacent the hook member when the hood is in the closed position there is an aperture in the hood of suificient size to accommodate the latch assembly The operating member 8 of the latch is metal and comprises the handle portion 10 which may have any suitable surface contours so that it fairs into the adjacent contours of the hood itself. Extending from the right hand surface of the handle member as seen in FIG. 2 are parallel, spaced apart mounting walls 11 and 12. These walls extend longitudinally of the handle member 10 and although they are shaped such that some portions extend further away from the handle member than other portions, the intermediate part of the operating member is essentially a channel-shaped structure in which the mounting walls 11 and 12 form the side walls of the channel and the handle member bridging the space between the mounting walls forms the web. The fact that the intermediate portion of the operating member is channel-shaped lends greatly to the rigidity of the operating member. One convenient way of forming the operating member is to cast the handle member 1% and the mounting walls 11 and 12 in one unitary piece.

An essentially rectangular mounting plate 13 is provided with laterally extending tabs 1% and 15 on the opposite longitudinal edges of the mounting plate. These mounting tabs as well as a marginal portion of the plate itself are provided with mounting holes 16 for riveting or bolting the mounting plate to the side wall of the hood in any convenient manner.

The central portion of the mounting plate is provided with an elongated rectangular aperture through which the mounting walls 11 and 12 extend toward the hook 4 mounted on the fire wall 3. The longitudinal edges of the aperture of the mounting plate are indicated at 1'7 and 18. One transverse edge is also indicated at 20. In this particular embodiment there is no transverse edge opposite the edge there being no transverse portion of the mounting plate at the upper end as seen in FIG. 1. The

lower transverse edge 20 is bent slightly out of the plane of the mounting plate as shown in FIG. 2 and serves as a sear engaging lip, the purpose of which will be explained in due course. Along the longitudinal edges 17 and 18 of the mounting plate aperture there are walls 21 and 22 extending perpendicularly to the plane of the mounting plate toward the hook member 4.

The operating member 8 is pivotally mounted about an operating axis formed by a pin 23 which passes through the Walls 21 and 22 of the mounting plate and is also journalled in the mounting walls 11 and 12 of the operating member. The pin 23 is suitably headed on each end during assembly. As shown the axis of the pin 23 is near the juncture of the handle 10 and mounting walls 11 and 12. Thus, the operating member forms a lever with the fulcrum at the pin 23.

At a suitable location spaced from the axis of the pin 23 there is a motion limiting stop pin 24 fixed between the mounting walls 11 and 12 and extending outwardly from the outside surfaces of the mounting walls by an amount sufficient to intercept the portions of the mounting plate along the longitudinal edges 17 and 18.

A coil spring 25 is assembled coaxially on the pin 23 with one end 26 of the spring extended to engage the stop pin 24. The other end 27 of the spring is extended to engage a tab 28 which is fixed to and extends perpendicularly from the wall 21 on the mounting plate. In this arrangement the spring is torsionally compressed so that it always exerts a force between pin 24 and tab 28 which tends to pivot the operating member clockwise about the axis of the pin 23 as far as the stop pin 24 will permit. In other words, if it were not for other operative elements of the latch, the spring 25 would hold the operating member in the unlatched or open position indicated in dotted outline at 80. in FIG. 2.

A hook engaging element in the form of a roller 30 is mounted on a suitable shaft 31 fixed between the mounting walls 11 and 12 at a position more distant from the handle member 10 than the pin 23. Preferably, the roller is simply a short length of tubing made from nylon or other comparably tough material and is made to turn freely on pin 31. The internal radius of the curved portion 7 of the hook member 4 and the external radius of the roller 30 are made substantially the same so that there is good bearing contact between the roller and the hook member when these two parts are engaged. The position of the roller when the operating member is in the open position is shown in dotted outline at 30a.

The roller serves two main functions. Gne of these is its keeping action, that is when the hood is closed and the operating member is in the locked position the roller engages the curved portion of the hook and prevents the hood from opening. The second function is that the roller acts as a guiding element to correct lateral misalignment of the hood with respect to the understructure of the vehicle. As an illustration of this, suppose that as the hood is being closed it is laterally displaced to the right with respect to the structural member 3. When the operating member 8 is moved from the open position shown at 8a, to the closed position, the roller is moved about the axis of pin 23 from the position 3%. In the course of this motion the roller will contact the straight portion of the hook member 4 and further rotation of the member about the axis of pin 23 will force the hood to the left to its intended position because the distance etween the axis of pin 23 and the roller 36 has been designedly fixed at a proper value. Where a pair of my new latches is used to secure the hoodone latch on each side as suggested above-the aligning action is particularly certain because the latches are acting in directly opposite directions to center the hood on the unde structure of the vehicle.

Another feature of my new latch is the good drawing down action which results from the roller 36 being r tated upwardly under the curved portion of the hook. With the latch assembly properly located on the hood the roller 30 will initially contact the curved portion 7 of the hook member before the operating member is in the fully closed and locked position. It follows that the terminal portion of the motion of the roller 3i about the axis of the pin 23 as the handle member is pushed into the fully closed position results in a substantial drawing down force on the hood. This insures a tight and rattle free contact between the hood and the understructure.

Locking of the operating member in the fully closed position is provided for by another novel feature of my new latch. A channel shaped sear 32, comprising side walls 33, 34 and web 35, is mounted between the mounting walls 11 and 12 of the operating member for pivotal motion about the axis of a pin 36, the ends of which are fixed in the mounting walls 11 and 12. The pin itself is journalled in the side walls 33 and 34 of the sear.

The axis of the pin 36 is spaced outwardly from the handle member 10 and the sear is oriented so that the web 35 is generally between the axis of the pin 35 and the inside surface of the handle 10 and extends substantially parallel to the inside surface of the handle member. At one end the sear is provided with a shoulder 37 and the sear extends in the direction opposite the shoulder portion 37 toward the pin 23. The scar is thus efi'ectively a lever with the fulcrum at the axis of the pin 36.

Intermediate the ends of the handle member 10 there is a trigger button having a cylindrical body part 33 and a hemispherical head which is larger in diameter than the button itself so that there is a circumferential shoulder 41 which bears on the inside surface of the handle member between the mounting walls 11 and 12. The button is free to move axially in a hole which extends through the handle member and the shoulder 41 limits the outward motion of the button. The curved surface of the hemispherical head bears against the web 35 of the sear so that when the button is pressed the sear is rotated about the axis of the pin 36 in the clockwise direction as seen in FIG. 2. The proportions of the sear are such that the angle to which the sear is rotated by depressing the button 38 is suflicient to rotate the shoulder 37 out of engagement with the lip 20 on the mounting plate.

As will be apparent from the inspection of the drawings, when the shoulder 37 of the sear is engaged with the lip 20 and the operating member, under the action the axis of pin 23. On the other hand, when the button .38 is depressed to rotate the sear about the axis of the pin 36, the shoulder 37 is moved out of engagement with the lip 20 and the operating member, under the action of spring 25, is free to pivot about the axis of the pin 23 to the open position shown at 8a. Of course, this same motion withdraws the roller 30 from engagement with the curved portion 7 of the hook member 4 so that the hood may be opened. Conversely, when the hood is closed on the understructure of the vehicle and the handle member is moved toward the closed position, the edges 42 of the walls of the sear act as camming surfaces which are engaged by the lip 20 on the mounting plate 16. The camming action rotates the sear clockwise about the axis of the pin 36 so that the shoulder 37 of the sear is permitted to pass the lip 20. If the latch assembly is mounted in the vertical position as shown in FIG. 2, the sear would rotate counterclockwise due to gravity, as soon as the shoulder had passed the lip 20. The operating member would then be locked in the closed position until the button 38 was again depressed. However, to provide for positive locking action regardless of the orientation of the latch, I provide coil spring 43 which is assembled coaxially on the pin 36. One end 44 of the coil spring is extended outwardly to bear on the underside of the web 35 of the sear and the other end 45 is extended outwardly to bear against a pin 46 fixed between mounting Walls 11 and 12 of the operating member. -In this arrangement the spring 43 exerts a force which tends to rotate the sear 32 counterclockwise about the axis of pin 36 as far as the circumferential shoulder on the button 33 will permit. As previously explained, the limit of this counterclockwise rotation is such that the shoulder on the sear is in engagement with the lip 20 on the mounting plate. In addition to maintaining the sear in the locked position the spring 43 also serves to maintain the button 33 in its outermost position from which it may be moved onlyby force deliberately exerted when it is desired to open the latch.

The details set forth above relate to only one particular embodiment of my invention. I do not intend that the scope of the invention is limited to these details, rather, the invention is defined in the following claims.

I claim:

1. A flush latch for releasably securing a closure member to a structure when said member and structure are in predetermined spaced positions, which latch comprises, in combination: a mounting plate adapted to be secured to said closure member, said plate having an elongated aperture therein; an operating member having an elongated handle portion; operating axis means su ported on said plate adjacent one end of said aperture for pivotably supporting said operating member, said operating member also having structural means extending through said aperture from said handle portion, which structural means rotatably engages said fixed axis means, and a rotatable roller fixed to said structural means at a position more remote from said handle portion than said operating axis; a sear engaging lip extending transversely of said mounting plate at the other end of the said aperture; a scar pivotally mounted on said structural means at a second axis which second axis is parallel to said sear lip and spaced from said handle portion on the same side thereof as said roller, said sear having a lip engaging portion nearer said handle portion than said second axis and spaced radially from said second axis by a distance which is equal to the separation between said second axis and said sear lip when said operating member is in a closed position; means on said handle portion for manually pivoting said sear about said second axis; and a hook rigidly attached to said structure at a position such that when said closure member and said structure are in said predetermined positions, the distance between said hook and said handle portion is substantially equivalent to the distance from said more remote position to said handle portion.

2. A fiush latch for releasably securing a closure member to a structure when said member and structure are in predetermined spaced positions, which latch comprises, in combination: a hook member rigidly aflixed to said structure, said closure member having an aperture therein, said hook member having a curved portion extending outwardly from said structure toward said closure member, one end of said aperture being adjacent said curved-portion when said closure member and structure are in said predetermined positions; an operating member having a pair of spaced apart and substantially parallel mounting walls and an elongated handle portion fixed to and bridging the space between said Walls; operating axis means disposed spaced from the inner side of said closure member adjacent said aperture one end, said operating member being disposed With said walls extending from said handle portion through said aperture and engaging said axis means,'said operating member being pivotally supported at said operating axis for limited rotational movement between a latched position and a released position, said operating member also having a cylindrical roller rotatably mounted between said mounting walls at a position more remote from said handle portion than said fixed axis for engagement with said curved portion when said closure member and structure are in said predetermined positions, said curved portion and said roller being adapted for mutual engagement when said operating member is in said latched position; a sear engaging lip extending transversely of said closure member aperture at a position spaced from said aperture one end; a sear pivotally mounted between said walls for limited rotation about a sear axis, the sear axis being spaced from the handle portion of said operating member, said sear having a portion thereon adapted to engage said lip on the side thereof opposite from said handle member when said operating member is in said latched position; a reciprocable member mounted in said handle member, one end of said member being accessible from the side of said handle member opposite said mounting Walls and the opposite end of said member bearing on a portion of said sear remote from said sear axis; and a sear spring mounted at said sear axis and acting between said sear and said operating member to urge the sear into contact with said reciprocable member.

References Cited in the file of this patent UNITED STATES PATENTS 2,424,962 Best Aug. 5, 1947 2,712,955 Andrews July 12, 1955 2,717,796 Cudney Sept. 13, 1955 2,721,750 Rudis et a1 Oct. 25, 1955 2,830,843 Seaburg et a1. Apr. 15, 1958 UNITED STATES PATENT OFFICE CERTIFICATION OF coBREcTIoN Patent No, 3 Ol2 805 December 12,, 1961 Lloyd R. Poe

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 5; line 8, for "and the operating member, under the action" read the operating member cannot be rotated about Signed and sealed this 17th day of April 1962.

(SEAL) Attest:

DAVID L. LADD Commissioner of Patents ESTON G0 JOHNSON Attesting Officer