GB2178790A - Cord clamp - Google Patents

Abstract

A cord clamp has a sleeve (20) and a plunger (10) displaceable in the sleeve against the force of a spring (14) formed integrally on the plunger. The sleeve (20) has a pair of windows (24) which can be aligned with an opening (13a) in a shank (13) of the plunger (10) when the plunger is pressed in to allow the movement of the cord through the clamp. Inner corners of the bars (15) forming the spring and arranged in a zigzag pattern are provided with circular section concavities to reduce material fatigue, while opposite sides of the windows (24) and opening (13a) are toothed for effective engagement with the cord. Opposite ends of the sleeve and the plunger are convexly ribbed to allow convenient gripping and use of the clamp. <IMAGE>

Description

SPECIFICATION Cord clamp The present invention relates to a cord clamp and, more particularly, to a device which is intended to be applied to a cord, string, band or strip for limiting the displacementthereof and which can be adjustably moved along the cord.

It is known to provide on a drawstring orothercord, band orstrip, an elementwhich is adapted to form a stop preventing retraction of the cord through a hole, for example in a garment. Such cord clamps also serveto clamp two strands of a cord together or even a greater number of strands in relative positions.

In general,cord clamps have been provided in a large number of configurations and the cord clamp which is ofthe greatest interestforthe purposes of this application comprises a sleeve into which a plungercan be forced against a spring counterforce,to align windows in the sleeve with an opening in the plunger orto cause registration thereof.

In this inwardly pressed position, a cord or a strand thereof can be displaced relative to the stop and, upon release ofthe pressure, which can be applied by the fingers of a hand of a user, the tendency forthe opening to become misaligned from the windows results in a clamping action between an edge ofthe opening intheshank and an opposite edge of a window to grip the cord or strands between them. The cord can be threaded through a device when the windows and opening are aligned or in registration and simple release of the pressure fixes the cord relative to the stop.

Cord clamps or stops ofthistype can be utilized in sporting articles such as rucksacks and similar receptacles, bags and the like. They can be utilized in gar mentsto draw in a portion ofa garment which istofit the wearer snugly butadjustably.

They have the advantage that they are more easily handled and even more versatile than buckles orthe like and are characterised by the high degree offorce which can be brought to bear to prevent undesired shifting ofthe cord, clamp orstop on acord.

There is a need for an easily operated cord clamp of the type described which is more reliable than earlier devicesforthis purpose, is inexpensiveto manufacture and especially has a longer useful life.

There is also a need for a cord stop which has less of a tendency to breakage or permanent deformation tending to impair its operation than earlier devices which have been proposed for the purpose.

According to the present invention a cord clamp or stop comprises a flattened sleeve open at one end and closed at an opposite end, and a plunger received in this sleeve and having a head projecting from the open end, the plunger being integral with a spring and having an opening in itsshankwhich can be aligned with windows in opposite sides orwalls ofthe sleeve to release a cord threaded through thewindows of the opening when the plunger is pressed into the sleeve, the spring serving to biasthewindows and opening out of alignmentforthe clamping action previously described.

In order to increase the life ofthe device, the spring can be formed from unitarily interconnected bars adjoining each other at angles in a zigzag configuration for internal corners which are provided with rounded concavities facilitating bending ofthe spring adjacent the concavities. Most advantageously these concavities are ofcircularcross section.

According to one preferred feature, external surfaces ofthe head and the closed end of the sleeve are provided with outwardly convexly curved and ribbed surfaces which facilitategreatlythe gripping ofthe device between fingers of the hand of a user, for example between the thumb and an index finger.

Furthermore, the edges ofthe omening in the shank andthewindowswhich gripthecord underthespring force are preferably toothed.

The rounded concavities at the inner corners of the junctions formed by the bars ofthe spring have been found to eliminate material fatigue of the spring orto greatly reduce that fatigue.

An embodiment of the present invention will now be more particularly described byway of example with reference to the accompanying drawings, in which: Figure 1 is an eievational view of a cord clamp embodying the invention with the plunger in its outwardmost position in which it is held by its spring; Figure2 is an elevational view ofthe plunger removed from the sleeve; Figure 3 is an elevational view ofthe sleeve with the plunger removed therefrom; Figure 4 is a sectional view th rough the sleeve showing the plungerfully depressed so that its open ing and the windows of the sleeve can be aligned; Figure 5is a side-elevational view of the device showing it clamped to a cord; and Figure 6isa detail-elevational view drawn to a much larger scale and showing the inner corner between two bars of the zigzag spring.

Referring now to the drawings, Figures 1 to3show a cord clamp having, as its principal elements, a plunger 10 and a sleeve 20.

The plunger 10 comprises a head 11 which has an outwardly curved and transversely ribbed surface 12 moulded unitarilywith a shankl3 which, in turn, is formed unitarilywith a zigzag spring 1 4whose bars 15 join at angularjunctions 16 (Figure 6), the internal corners of which are provided with circular concavities 17.

The flattened end 18 ofthe spring can come to rest upon a surface 21 ofthe sleeve 20 provided within the latter.

The shank 13 has athrough window 13a which is elongate in a direction transverse to the direction in which the plunger is pressed into the sleeve (arrows P in Figure 4) so as to have longer sides 13b and 13the latter being toothed. Adjacentthe long sides 13c, moreover, a lug 1 3d projects from the shank and engages in one ofthe windows of the sleeve to prevent withdrawal ofthe plunger from the sleeve.

The sleeve 20 has an open end 22 and a closed end 23, the latter being convexly curved and ribbed opposite the ribbed surface 12 of the head, to permit the device to be readily gripped between, say, the thumb and the index finger of a hand of the user.

The sleeve 20, moreover, is formed with two elon gate windows 24which have long sides 24a and 24b, the former ofwhich is toothed so that when a cord C is clamped within the windows ofthe opening of the plunger, the toothed edges 1 3e and 24a bear in opposite directions against the cord. The lug 13d engages the upper edge 24 of one of the windows to prevent withdrawal ofthe plunger beyond the position shown in Figure 1.

When the plunger is fully depressed by the applica tion of pressure as represented bythe arrows Pin Figure 4, the lug 13d can engage in a recess 24c in the long side 24b of a window 24. The windows are thus aligned with the opening in the shank and the cord C can be drawn through them to the desired position.

Release ofthe plungerthen locks the cord in place.

The toothed formations along the opposite edges ofthe windows in the sleeve and the opening in the plunger, in combination with the effect of the spring, ensures a fixing of the device to the cord and, where several strands of a cord traverse the opening of these windows, the strands relative to one another even when considerable force is applied,for example in the form oftension to the strand againstthe clamp.

The outwardlyconvexordomed configuration of the ribbed ends of the plungerand sleeve facilitates manipulation and,ofcourse,thecircularconcavities atthe inner corners ofthe pairs ofthe spring counter material fatigue.

Claims (8)

1. A cord clamp comprising a sleeve which is open at one end, closed at an opposite end, and has respective mutually aligned windows formed proximal to said one end in opposite walls of said sleeve through which a cord can be passed, and a plunger received in said sleeve and comprising a head disposed outside said sleeve and adapted to be pressed toward said sleeve, a shank adjacent said head and formed with a transverse hole registrablewith said windows upon pressing of said head toward said sleeve and said shank into said sleeve, and a spring having interconnected bars in a zigzag configuration integral with said shank and bearing upon a surface of said sleeve within said sleeve and including internal corners between them, said internal corners expediently being formed with rounded concavities facilitating bending of said spring adjacentsaid concavities, external surfaces of said head and said closed end of said sleeve preferably being outwardly con vexlycurved and ribbed, and edges of said windows and said opening engageable with said cord for pre- ference being toothed.

2. Acordclampasclaimed in claim 1,wherein said sleeve and said plungerareeach unitarily moulded from a synthetic resin.

3. A cord clamp as claimed in either claim 1 or claim 2, wherein said hole is elongate in a direction transverse to the direction in which said plunger is pressed into said sleeve, said hole having opposite long edges, one of said edges being toothed.

4. A cord clamp as claimed in claim 3,wherein said windows are each elongate in said direction transverse to the direction in which said plunger is pressed into said sleeve, said windows each having opposite long sides, one of said sides of each window being toothed.

5. Acordclampasclaimed in claim 4,whereinthe toothed sides of said windows are opposite the toothed edge of said hole.

6. A cord clamp as claimed in any one of the preceding claims, comprising at least one lug arranged on said shank and engaging in one of said windows for preventing separation of said plunger from said sleeve.

7. A cord clamp as claimed in any one of the preceding claims,wherein said sleeve and said shank are offlattened cross section.

8. A cord clamp substantially as hereinbefore de scribedwith reference to the accompanying drawings.