GB2197020A - Fastening - Google Patents

Description

1 GB2197020A 1

SPECIFICATION

Flexible draw latch This invention relates generally to over-center 70 draw latches for use in securing two closure members together. More specifically, the pre sent invention relates to overcenter draw latches of the flexible or elastic type.

Many types of over-center draw latches are 75 generally known in the art. One such type of over-center draw latch is taught in my U.S.

patent Nos. 3,181,095, issued May 4, 1965, and 3,466, 076, issued September 9, 1969.

The latches disclosed in these patents essen- 80 tially comprise a keeper and a one-piece part having three segments: a base segment, a locking segment, and an intermediate segment wherein the intermediate segment is flexibly connected to the base and locking segments. 85 When in a latched condition, the locking seg ment is detachably connected to the keeper and is in overlying relation to the keeper, the base segment, and the intermediate segment.

These latches were often considered desir- 90 able because they provided positive over-cen ter latching, were lightweight and also were inexpensive to manufacture. Furthermore,.

these latches were attractive in appearance.

Typically, however, these latches were of a molded plastic construction and were incapable of use in situations where high loads were placed on the latch. Another disadvantage in these latches was the fact that considerable precision was required in the installation of the 100 latch and the keeper in order for the latch to operate properly.

Flexible draw latches are also known in the art and have been used for many years. Per- haps the most simple example of a flexible draw latch comprises a mounting bracket, a rubber stretch arm af fixed to the bracket, and a keeper. These flexible draw latches are typically used to secure loose fitting hoods or covers on heavy machinery or mechanical equipment. In operation, the rubber stretch arm would be pulled up and into engagement with the keeper, whereby the elasticity of the rubber arm would keep the hood or cover secure. Although these latches were not very pleasing in appearance and did not provide the more positive over-center latching action, they were considered desirable because the flexibility of the rubber arm compensated for misal- ignment of the bracket and keeper during installation. Another advantage of these flexible draw latches was that the load capability of the latch could be varied, within a range, by simply increasing or decreasing the distance between the bracket and the keeper and, thus, the tension on the rubber stretch arm. In high load situations, this type of latch became unpractical, however, because of the difficulty in stretching the heavy- duty rubber arm re- quired in such situations.

Another type of flexible draw latch is also known which was primarily developed to overcome the disadvantages of the above-mentioned flexible latch by providing a lever handle to assist in stretching the rubber arm. Essentially, these lever-assisted flexible draw latches comprise a bracket, a rubber stretch arm, a lever handle and a keeper. The rubber stretch arm is connected at one end to the bracket and connected at the other end to the lever at a point intermediate the ends of the lever. To operate the latch, the fever handle was inserted in the keeper and pivoted to stretch the rubber arm and then'seating to secure the latch with a positive over-center action. Despite its advantages over the previous flexible draw latches, however, these lever assisted latches were considered unsightly and their use was essentially limited to high load situations where heavy-duty latches are required.

I have invented a simple draw-pull latch for use in securing two closure members together which provides the advantages of a flexible locking member in an aesthetically pleasing latch which is inexpensive to manufacture, easy to use, and has a wide variety of practical applications.

Briefly, the present invention comprises a flexible over-center draw latch for use in securing two closure members together, comprising a keeper adapted to be affixed to one of the members, a mounting bracket adapted for being affixed to the other member, a lever pivotally connected to the mounting bracket, and a flexible locking member pivotally connected to the lever. In operation, the locking member is disposed over the keeper and pushed toward the closure member to a latched position overlying the bracket, the keeper and the lever, whereby the latch is secured by a positive over-center -latching action. The tail end of the locking member is provided with a concave surface to facilitate the lifting of the locking member to an unlatched position. The nose end of the locking segment is preferably provided with a transverse cross-pin which engages the keeper to prevent localized stress on the flexible lock- ing member when the latch is in its closed position.

Accordingly, it is a primary object of the present invention to provide a novel flexible draw latch.

It is another object of the present invention to provide a flexible draw latch having positive over-center latching action.

It is another object of the present invention to provide a draw latch having aJlexible lock- ing member.

It is a further object of the invention to provide a flexible draw latch having variable load capabilities.

It is another object of the invention to pro- vide a flexible over-center draw latch wherein 2 GB2197020A 2 the flexible locking member is in overlying relation to the rest of the latch components when in the latched condition.

It is a further object of the invention to ac- complish the above objects by providing a keeper, a mounting bracket, a lever pivotally connected to the mounting bracket, and a flexible locking member pivotally connected to the lever and having a nose end adapted to receive the keeper.

It is another object of the invention to provide a latch having the above objects wherein the nose end of the latch is provided with a transverse cross-pin which engages the keeper to relieve the stress on the locking member.

It is a further object of the invention to ac complish the above object in a flexible draw latch operated by a simple push-to-latch or lift-to-unlatch action.

These and other objects of the invention will become apparent upon a reading of the following detailed description of the invention with reference to the drawings, and the ap pended claims.

Reference is made to the accompanying drawings, wherein:

Figure 1 is a perspective view of a preferred embodiment of the present invention, as mounted to a pair of closure members, illus- trated in the unlatched condition; Figure 2 is a sectional view of the invention taken along line 2-2 of Fig. 1; Figure 3 is a perspective view of the inven tion illustrated in a partially latched condition; Figure 4 is a sectional view taken along line 4-4 of Fig. 3; Figure 5 is a perspective view of the inven tion illustrated in fully latched condition; Figure 6 is a sectional view taken along line 6-6 of Fig. 5; Figure 7 is a sectional view similar to Figure 6, showing the preferred embodiment of the invention in which the nose end of the locking member is provided with a transverse cross pin; Figure 8 is a rear elevational view of the preferred embodiment of the invention taken along line 8-8 of Figure 7.

With reference now being made to the Fig- ures, particularly Fig. 1, the flexible over-center draw latch of the present invention comprises a keeper 10, a mounting bracket 20, a lever 30, and a locking member 40 which is made of a flexible, resilient material, pref9rably rubber. As seen in Figs. 1 and 2, keeper 10 is adapted for being af fixed to a closure member, such as panel 11, and comprises a cylindrical member 12 having a bore 13 therethrough and an outwardly extending annular flange 14 at the outer end of cylindrical member 12. As seen in the Figures, keeper 10 is affixed to panel 11 by a screw 15 or other suitable fastener disposed within the bore 13 of cylindrical member 12. With reference to Fig. 2, the annular flange 14 forms a seat for the head of screw 15 to provide a smooth exterior contour on the face of keeper 10, when assembled. In the preferred embodiment, keeper 10 is made of stamped metal construction.

Mounting bracket 20, as seen in Fig. 1, is preferably a wedge-shaped member having spaced-apart opposing side walls 21, 22 and a bottom wall 23. Bottom wall 23 is prefera- bly provided with a pair of spaced-part apertures 24, 25 to facilitate the mounting of mounting bracket 20 to a closure member, such as panel 26, by screws 27, 28 or other suitable fasteners. In the preferred embodi- ment, mounting bracket 20 is of a stamped metal construction, preferably stainless steel.

Lever 30, as seen in the Figures, comprises a bar having a transverse aperture 31, 32 at the longitudinal ends thereof through which is disposed a pin 33, 34 or the like to facilitate the pivotal mounting of lever 30 to mounting bracket 20 on the one end and locking member 40 on the other. Lever 30 is preferably of molded or extruded plastic construction. As seen in the Figures, lever 30 is mounted near the outer edges of side walls 21, 22 of mounting bracket 20, whereby lever 30 is held in spaced relation to the face of panel 26.

Locking member 40, as mentioned previ ously, is preferably made of a rubber or other like material having sufficient flexibility and re silient properties. As seen in Figs. 2-6, locking member 40 is preferably of substantially flat- tened triangular shape having a nose section 41, a tail section 42 and a crown 43 on the exterior face of locking member 40 intermediate the nose and tail sections. As seen in Fig. 1, the interior face of locking member 40 is provided with a relatively narrow channel 44 in tail section 42, which channel 44 is sized to substantially coincide with the width of]ever 30 and to receive lever 30 therein when the latch is moved to a latched position (See Fig. 6). Extending from channel 44 toward nose section 41 is a channel 45 which, as seen in Fig. 1, is substantially longer and wider than channel 44, whereby a shoulder 46 is formed between the connection of the channels 44 and 45.

As also seen in Fig. 1, channel 45 is widest at the point adjacent shoulder 46 and is sized so as to receive therein the mounting bracket 20 when the latch is moved to a latched posi- tion (See Fig. 6). From its widest point, channel 45 narrows slightly as it extends toward nose section 41, whereby the cross-sectional area of locking member 40 along channel 45 is constant. In this construction, the elonga- tion or stretch of locking member 40 when the latch is closed is uniform to prevent the formation of "weak points" in the locking member and consequential localized deformation and fatigue of the resilient material. A notch 47 is provided at the end of channel 45 3 GB2197020A 3 adjacent the nose section 41 (see Fig. 2) which is adapted to receive therein the annular flange 14 of keeper 10 when the latch is closed, as seen in Figs. 4 and 6.

The inner face 48 of nose section 41, as seen in the Figures, is bevelled slightly outwardly and upwardly to facilitate the engagement of locking member 40 with the keeper 10 (see Figs. 4 and 6). In the preferred embodiment, inner face 48 of nose section 41 forms a 10' angle with the vertical as illustrated in Fig. 6, which has been found to provide sufficient clearance for engaging keeper 10 and further to substantially prevent local- ized deformation and fatigue of the nose section 41 when the latch is closed.

The end of tail section 42 is provided with a concave surface 49 which facilitates the unlatching of the latch by an outward pull of tail section 42 away from panel 26, as described hereinbelow.

With reference to the preferred embodiment of the invention illustrated in Figures 7 and 8, the latch comprises a keeper 110 having a mounting region 112 and a curved leg region 113. The mounting region 112 is adapted for being affixed to panel 111 such as by screws or the like disposed within apertures in the mounting region 112. As seen in Figure 7, curved leg region 113 is of an S-shaped conf iguration and is attached to the mounting re gion 112 so as to project outwardly from panel 111.

A bracket 120 is also provided for mount ing the latch to panel 126 and has the same 100 shape and configuration as described above.

That is, bracket 120 comprises a pair of spaced-apart side walls 121, 122 and a bot tom wall 123 which bottom wall 123 is adapted for being affixed to panel 126 by screws or the like 127, 128. Lever 130 is pivotally connected to bracket 120 by pin 133 and is connected to tail section 142 of locking member 140 by pin 134 as described above in connection with the other embodi- ments. Locling member 140 is also of similar shape and design as above-described, having a channel 144 in tail -end 142 thereof to ac commodate lever 130 therein and a larger channel 145 adjoining channel 144 so as to 115 form a shoulder 146. It should be noted that channels 144 and 145 are of slightly different configuration due to the reverse orientation of mounting bracket 120 in the preferred em- bodiment. (Compare Figure 7 and Figure 7). This reverse orientation of mounting bracket 120 as seen in Figure 7 is desirable because it allows for mounting of bracket 120 farther away from the terminal edge of panel 126 without unnecessarily increasing the overall length of the latch.

The nose end 141 of locking member 140 is different in construction than the previous embodiments and is provided with a channel 147 therein which is sized so as to receive curved leg 113 of keeper 110 (see Figure 8). Transversely disposed through nose end 141 and channel 147 is a bore 151 within which is disposed a pin 150. As seen in broken lines in Figure 8, cross-pin 150 traverses channel 147 whereby it engages with curved leg 113 of keeper 110 when the latch is moved to a closed position, whereupon crosspin 150 nests within a concave depression of S-shaped curved leg 113.

In the preferred embodiment, localized deformation at the nose end 141 of locking member 140 is virtually eliminated. In addition, the use of crosspin 150 allows the locking member 140 to lie flat against the panel when in the latched condition for increased latching strength and better overall appearance.

The operation of the flexible over-center draw latch will now be described with refer- ence to the sequential illustration thereof from a fully open, unlatched position (Figs. 1 and 2) to a fully closed, latched condition (Figs. 5 and 6), it being understood that the preferred embodiment illustrated in Figures 7 and 8 op- erates in a like manner. From the fully open position of Figs. 1 and 2, the locking member 40 is moved outwardly and upwardly and pivoted inwardly through lever 30 and pivot pins 33, 34 to the position illustrated in Figs.

3 and 4 whereby the keeper 10 is received in the channel 45 and notch 47. From the position illustrated in Figs. 3 and 4, the latch is closed by application of force to the locking member 40 in the direction of arrow 50 in Fig. 4. Upon movement of locking member 40 toward panel 26 to close the latch, [ever 30 will pivot about pin 33 and locking member 40 will elongate slightly as the central axis of the latching force is reached. Once the lever 30 crosses the central axis, lever 30 will pivot about pins 33 and 34, and locking member 40 will contract and "snap" to the closed position of Figs. 5 and 6 to provide positive over-center latching. The resiliency of the locking member 40 retains the panels 11 and 26 securely together.

To open the latch, the forefinger is placed against concave surface 49 on tail section 42 and the thumb is placed on the face of locking member 40 near the crown 43 and the latch is snapped open by a simple lifting and squeezing movement of the thumb and forefinger. From the resulting position of the latch illustrated in Figs. 3 and 4, the locking mem- ber 40 is lifted to disengage the keeper 10 and the panels 11, 26 can be separated.

As seen in Fig. 5, the appearance of the latch when fully closed is a function of the shape and appearance of the locking member.

Thus, locking member 40 can be made of any size or shape as may be considered desirable and furthermore may be of any color or colors, and the face thereof may be provided with a logo, trademark or other suitable indi- cia, as desired.

4 GB2197020A 4 It can be seen from the above specification, the latch of the present invention, due to the presence of a flexible, resilient locking member, provides all of the advantages associated with flexible draw latches. For example, the flexibility of the locking member insures a positive latching action even if the mounting bracket and the keeper are not in precise alignment, and thus compensates for misalign- ment of the bracket and keeper during installation. In addition, the load or tension generated by the locking member can be varied, within a particular range, by simply increasing or decreasing the distance between the mounting bracket and the keeper to provide a lesser or greater degree of stretch in the locking member when the latch is closed. Of course, if the distance is too short the locking member will not properly engage the keeper and the latch will be ineffective. Likewise, if the distance is too large, the latch will tend to release spontaneously because the stretch capabilities of the locking member have been exceeded.

Preferred forms of the invention have been described and illustrated herein for purposes of illustration only and not for purposes of limitation, and various modifications or alternatives may suggest themselves to those skilled in the art, all of which are intended to be within the spirit and scope of the present invention as defined in the appended claims.

Claims (18)

1. An over-center draw latch for use in securing two closure members together, comprising:

a) a keeper adapted to be affixed to one of the closure members; b) a mounting bracket adapted to be affixed to the other closure member; c) a lever pivotally connected to said mounting bracket; d) a locking member pivotally connected to said lever and adapted to detachably engage said keeper, said locking member being disposed in over-center position overlying said keeper, said mounting bracket and said lever when said latch is in a closed, latched position, and wherein said locking member is made of a flexible, resilient material and the lever is relatively rigid whereby the member stretches as the member is moved to its overcenter position.

2. A draw latch according to Claim 1, wherein said locking member further comprises an element transversely disposed therethrough and positioned to detachably engage said keeper when said latch is in said closed position.

3. The latch of Claim 1 or 2, wherein the pivot connection between said]ever and said locking member is closer to the closure member when the latch is in the closed, latched position than said connection between said lever and said mounting bracket.

4. The latch of any preceding claim, wherein said locking member is made of rubber.

5. The latch of any preceding claim, wherein said locking member is provided with a first channel therein adapted to receive said lever when said latch is moved to said closed position and a second channel adjacent to said first channel, adapted to receive said mounting bracket when said latch is moved to said closed position.

6. The latch of Claim 5, wherein the crosssectional area of said locking member along the length of said second channel is constant.

7. The latch of any preceding claim, wherein said mounting bracket comprises a wedgeshaped member having a bottom wall adapted to receive fastening means for affixing said bracket to the other closure member and a pair of spaced- apart walls outwardly extend- ing from said bottom wall, wherein said lever is disposed between said side walls and connected thereto by a pin in spaced relation to said bottom wall.

8. The latch of any preeding claim, wherein said keeper comprises a substantially straight mounting region and an S- shaped leg attached to said mounting region and extending therefrom.

9. The latch of Claim 2, or any ne of Claims 3 to 7 as appenclant to Claim 2, wherein said locking member comprises a nose portion adapted to receive said keeper therein and a tail portion to which said lever is connected, said tail portion having a concave surface to facilitate movement of said locking member to an unlatched position, and wherein said transverse element is disposed through said nose portion.

10. An over-center draw latch for use in securing two closure members together, comprising:

a) a keeper adapted to be affixed to one of the closure members; b) a mounting bracket adapted to be affixed to the other closure member, said mounting bracket having a bottom wall and a pair of spaced-apart side walls outwardly extending from said bottom wall; c) a lever disposed between said spaced- apart side walls of said mounting bracket and pivotally connected thereto at a location spaced from said bottom wall of said mounting bracket; d) a locking member pivotally connected to said lever and adapted to detachably engage said keeper, wherein said locking member is disposed in an over-center position overlying said keeper, said mounting bracket and said lever when said latch is in a closed, latched position, and wherein said locking member is made of a flexible, resilient material and said]ever is made of a relatively rigid material, whereby the member stretches as the member is moved to its over-center position, the lock- ing member further comprising an element transversely disposed therethrough and positioned to detachably engage said keeper when said latch is in said closed position.

11. The latch of Claim 10, wherein the pi- vot connection between said lever and said locking member is closer to the closure member than said pivot connection between said mounting bracket and said lever when said latch is in said closed, latched position.

12. The latch of Claim 10, wherein said locking member is made of rubber.

13. The latch of Claim 10, wherein said locking member is provided with a first channel therein adapted to receive said lever when said latch is closed, a second channel adjacent said first channel adapted to receive said mounting bracket when said latch is moved to said closed position and a third channel adjacent to said second channel adapted to re- ceive said keeper when said latch is moved to said closed position.

14. The latch of Claim 13, wherein the cross-sectional area of said locking member along the lengh of said second channel is con- stant.

15. An over-center draw latch for use in securing two closure members together comprising:

a) a keeper adapted to be affixed to one of the closure members, said keeper comprising a cylindrical member having an annular flange connected thereto and a bore extending therethrough; b) a wedge-shaped mounting bracket adapted to be affixed to the other closure member comprising a bottom wall and a pair of spaced-apart side walls disposed substantially perpendicular to said bottom wall c) a lever disposed between said spacedapart side walls of said mounting bracket and pivotally connected thereto by a transverse pin; d) a locking member made of a flexible, resilient material having a nose section adapted to receive said keeper therein, said nose section having a pin transversely disposed therethrough and positioned to detachably engage said keeper and a tail section pivotally connected to said lever, said locking member hav- ing a first channel in the tail section thereof adapted to receive said lever when said locking member is moved to a closed latched position; a second channel adjacent said first channel and extending towards said nose section, said second channel being adapted to receive said mounting bracket when the latch is moved to a closed position, and a third channel adjacent to said second channel adapted to receive said keeper when the latch is closed, wherein the cross-sectional area of said locking member along the length of said second channel is constant, and wherein said pivot connection between said lever and said tail section of said locking member is closer to the closure member than the pivot connec- GB2197020A 5 tion between said lever and said mounting bracket when said latch is in said closed position.

16. The latch of Claim 15, wherein said tail section of said locking member is provided with a concave surface to facilitate the lifting of said locking member and the unlatching of said latch.

17. The latch of Claim 15 or 16, wherein said locking member is made of rubber.

18. The latch of Claim 15, 16, or 17, wherein said mounting bracket is affixed to a panel or the like by screws disposed through said bottom wall of said mounting bracket.

Published 1988 atThe Patent Office, State House, 66/71 High Holborn, London WC 1 R 4TP. Further copies may be obtained from The Patent Office, Sales Branch, St Mary Cray, Orpington, Kent BR5 3RD. Printed by Burgess & Son (Abingdon) Ltd. Con. 1/87.