GB2559439A

GB2559439A - Locking mechanism for pliers or clamps

Info

Publication number: GB2559439A
Application number: GB1714597.0A
Authority: GB
Inventors: Abraham David
Original assignee: Individual
Current assignee: Individual
Priority date: 2017-09-11
Filing date: 2017-09-11
Publication date: 2018-08-08
Also published as: GB201714597D0

Abstract

The locking mechanism includes levers with symmetrical jaws and handles on each side. The mechanism is connected via a threaded hole 1 in a main fulcrum and connections 3, 6 in the handles. Channeled pivots 3 in the handles may hold and force the arms 6 of a V-shaped slider block up and down an unthreaded section 4 of a thumbscrew 5. A stopper 2 may be fixed to the unthreaded end 4 of the thumbscrew nearest the fulcrum. This locks against the V-shaped slider block when turned anti-clockwise whilst the handles are squeezed, locking the slider arms and preventing the jaws from opening. The thumbscrew is positioned for convenient access to forefinger and thumb of either hand for a one-handed clamping operation. The mechanism may be incorporated centrally into the jaw sand handles.

Description

(54) Title of the Invention: Locking mechanism for pliers or clamps Abstract Title: Locking mechanism for pliers or clamps (57) The locking mechanism includes levers with symmetrical jaws and handles on each side. The mechanism is connected via a threaded hole 1 in a main fulcrum and connections 3, 6 in the handles. Channeled pivots 3 in the handles may hold and force the arms 6 of a V-shaped slider block up and down an unthreaded section 4 of a thumbscrew 5. A stopper 2 may be fixed to the unthreaded end 4 of the thumbscrew nearest the fulcrum. This locks against the V-shaped slider block when turned anti-clockwise whilst the handles are squeezed, locking the slider arms and preventing the jaws from opening. The thumbscrew is positioned for convenient access to forefinger and thumb of either hand for a one-handed clamping operation. The mechanism may be incorporated centrally into the jaw sand handles.

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FIG 6

FIG 7

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FIG 10

FIG 11

LOCKING MECHANISM FOR PLIERS OR CLAMPS

The present invention pertains to a locking mechanism used in hand tools where gripping or holding of the work-piece is carried out.

There are many types of holding and gripping hand tools that can be used for various general or specific purposes. They are usually categorised into holding, gripping and clamping hand tools.

Pliers are a hand tool used to hold objects. Generally, pliers consist of a pair of metal first-class levers joined at a fulcrum, allowing the force of the hands grip to hold an object. Gripping hand tools commonly used are locking pliers, otherwise known as “mole” or “vice” grips. Locking pliers use a toggle mechanism pivotally connected to a moveable jaw. The other jaw is fixed. Adjustments in the force applied by the jaws to the work piece are generally made by turning an adjusting screw mounted in the fixed handle that engages the toggle locking mechanism. A clamp is a fastening device used to hold or secure objects tightly. There are many different types of clamping hand tools that use various types of mechanisms in their design, but relevant to the present invention a “scissor action” first class lever ratchet mechanism arrangement is broadly described. A ratchet type clamping hand tool is usually made from moulded plastic and uses a mechanism that consists of a toothed strip that connects with a pawl or other toothed strips. When the handles are squeezed the pawl clicks into the grooves in the teeth resulting in the jaws locking onto the work-piece and clamping occurs. The pawl is released by a lever and a spring forces the handles and jaws apart. Clamping a workpiece can be achieved by using just one hand whilst the other hand is free to hold the work-piece in position. Smaller pliers with ratchet systems are used to hold small parts in the medical, model making and electronic industry.

The categories listed above can be loosely interpreted and specific categories can have characteristics that are common but disadvantageous to each other. For example locking pliers that use a toggle mechanism are usually classed as a gripping tool, but they can be used for clamping in some circumstances. However locking pliers are not usually used for clamping because they do not have the spanning capacity that ratchet clamps have due to the fixed jaw arrangement. Also they are not as fast as ratchet clamps when gripping a work piece due to the laborious trial and error method that the operator uses to get the optimum adjustment pressure and damage to the surface of the work-piece can occur. Besides, because one jaw is stationary whilst the other jaw is moveable, an unintentional change in the position of a clamped work piece is likely to occur. Other groups that have common characteristics are pliers and locking pliers. They also have advantages and disadvantages when compared to each other. Pliers without locking mechanisms are usually classed in the holding tool category. In operation they use the force of the hands grip to secure an object. An object can be manipulated faster and time is not wasted controlling a locking mechanism. They are simpler and have fewer components, making them lightweight, sleeker and more manipulative. Control is more precise and damage to the work-piece is less severe. However the main disadvantage when using pliers is that strength and dexterity are required of the operator due to the lack of a locking mechanism. If the operator has a weak or shaky hand grip, it can be difficult to tighten and manipulate objects. Also, tightening or loosening objects such as nuts and bolts can be laborious because the jaws of the pliers are unintentionally forced open due to the irregularly shaped projections. Again, clamps with ratchet systems can be used to hold or grip objects but when twisting occurs the moulded plastic and the ratchet mechanism would be likely to fail. Control would not be precise when manipulating objects because the release lever spring would snap open the jaws and handles.

It would therefore be desirable to have a combined holding, gripping and clamping handtool whereby the user can quickly hold and manipulate objects, whilst having the means to clamp and lock the work-piece firmly when required. It would also be useful to operate the pliers or clamps with one hand whist the other hand is free to hold the work-piece in position

The present invention has therefore been made in view of the conventional problems as described above.

The main object of the present invention is to provide a mechanism for pliers or clamps that use a “scissor action” first class lever system, whereby the user can hold and manipulate the work-piece in an open and unlocked position using the force of the operator but alternatively, when required, secure the work-piece firmly in a closed and locked position.

It is another objective of the present invention to provide a mechanism for pliers or clamps that use a scissor action first class lever system, whereby clamping or gripping a work-piece securely can be achieved by using one hand whilst the other hand is free to hold the work-piece in position.

It is another objective of the present invention to provide a mechanism for pliers or clamps that use a scissor action first class lever system whereby various configurations of the jaws and handles may be used to suit various applications.

It is a further objective of the present invention to provide a mechanism for pliers or clamps that use a scissor action first class lever system whereby the user can execute speedy and precise control during the clamping and gripping process.

The above objectives are achieved as follows:

A pair of first class levers joined at a fulcrum with jaws and handles on each side whereby grooved pivot bolts built into both handles and in operation force a connected V shaped slider with arms up and down an unthreaded section of a thumbscrew attached to a block with a threaded hole at the fulcrum point. A stopper fixed to the unthreaded end of the thumbscrew nearest the fulcrum locks against the V shaped slider with arms when the thumbscrew is turned anti-clockwise whilst the handles are squeezed, thus preventing the jaws from opening and also performing a clamping operation. The operator has control over the tightness of the material in the jaws by turning the thumbscrew whilst pressing the handles together. The thumbscrew can be turned with the fore finger and thumb whilst pressing the handles together with the same hand whilst the other hand is free to hold the work-piece in position.

Various configurations of the jaws and handles may be used in conjunction with the mechanism of the invention. The mechanism can be centrally fixed for ease of use.

The mechanism of the invention is intended to be used with pliers or clamps where gripping or holding of the work-piece is carried out.

The invention will be further described with reference to the accompanying drawings in which:

FIG.1 shows a front view of pliers with the locking mechanism incorporated.

FIG.2 shows a perspective view of pliers with the locking mechanism incorporated.

FIG.3 shows closed pliers locked with the locking mechanism.

FIG.4 shows closed pliers unlocked.

FIG.5 shows open pliers gripping an object and in a locked position.

FIG. 6 is a different embodiment of the present invention showing a clamped work-piece

FIG.7 is another embodiment of the present invention showing a nut within locked jaws.

FIG.8 is yet another embodiment of the present invention showing parallel pliers with the locking mechanism incorporated.

FIG.9 shows a front view of pliers with the locking mechanism incorporated.

The handles and jaws are configured to allow the v shaped slider and thumbscrew to run central.

FIG. 10 shows a plan view. The mechanism is incorporated centrally into the configured jaws and handles.

Fig. 11 shows the handles with ergonomically friendly shaped plastic sleeves hiding the slider arms.

Referring to Figs. 1 -11, there are shown a pair of first class levers joined at a fulcrum with jaws and handles on each side, whereby channelled pivot bolts 3 built into both handles and in action force a connected V shaped slider with arms 6 up and down an unthreaded section 4 of a thumbscrew 5 attached to the fulcrum connecting block with threaded hole 1. A stopper 2 fixed to the unthreaded end 4 of the thumbscrew 5 nearest the fulcrum locks against the V shaped slider with arms 6 when the thumbscrew 5 is turned anti-clockwise whilst the handles are squeezed, thus preventing the jaws from opening and also performing a clamping operation. The thumbscrew 5 can be turned with the fore finger and thumb whilst pressing the handles together with the same hand whilst the other hand is free to hold the work-piece in position. The operator has control over the tightness of the material in the jaws by turning the thumbscrew 5 with either hand whilst pressing the handles together. The mechanism can be centrally fixed for ease of use.

Fig 1 shows a front view of pliers with jaws in a locked position. The force of the users hand is shown gripping an object whilst the thumbscrew is turned with the thumb and index finger. The jaws are locked and prevented from moving due to a stopper fixed to the unthreaded end of the thumbscrew nearest the fulcrum. The stopper pushes against the V shaped slider with arms and prevents the channelled pivots on the handles from moving the slider forwards. The operator has control over the tightness of the material in the jaws by turning the thumbscrew.

Fig 2 shows a perspective view of pliers with the proposed mechanism attached. The proposed locking mechanism is connected as a unit to pliers or clamps that use a scissor action first class lever system arrangement via the main fulcrum and pivot holes situated in the handles. The proposed locking mechanism consists of several components, namely, the fulcrum connecting block with threaded hole, V shaped slider with arms, thumb screw with fixed stopper and grooved pivot bolt heads. The fulcrum connecting block with threaded hole component is attached loosely to the fulcrum to allow the jaws to open and close. The threaded hole contains the threaded section of the thumbscrew. The V shaped slider with arms component is made up of a shaped block with a hole running through the centre. Two arms each side, preferably rectangular in cross section protrude from the slanted sides of a shaped block. The arms are angled to stabilize the mechanism and to improve the clamping force. The thumbscrew component has a stopper fixed at the region between the threaded and unthreaded rod and at the end there is a knurled head that can be operated with the index finger and the thumb of either hand. There are two grooved pivot bolt components. The pivot bolt head components have a channel running through the heads to accommodate the arms of the V shaped slider. The pivot bolts are attached to holes in the handles. Fig 3 show closed pliers in a locked position. The stopper fixed at the region between the threaded and unthreaded rod prevents the jaws from opening. The pliers can be unlocked by turning the thumbscrew anti-clockwise thus releasing the stopper from the V shaped slider. Fig 4 shows closed pliers unlocked. The stopper is the furthest away from the V shaped block. The pliers can now be used conventionally for holding and manipulating objects but can be locked when required. Fig 5 shows the pliers open and gripping an object in a locked position. The jaws are fixed to the object until the stopper is released by the thumbscrew. Fig 6 shows the proposed mechanism used for clamping or gripping two objects. The proposed mechanism is incorporated into the shown first class lever style clamping, gripping or holding hand tool. The locked object can be twisted by the operator without causing the hand tool to fail or break. The two objects can be held and manipulated before executing the lock.

It is understood that this invention has scope for a variety of conventional symmetrical designs. Fig 7 shows the proposed mechanism incorporated into a first class lever style, gripping or holding hand tool. This type of hand tool would be useful for holding, gripping and wrenching. Fig 8 shows parallel pliers with the locking mechanism incorporated.

Fig 9 shows the handles and jaws configured to allow the v shaped slider and thumbscrew to run central. The thumbscrew enters the middle of the main pivot and the sliders are housed inside the handles. Fig 10 shows a plan view of the mechanism incorporated centrally into the configured jaws and handles. Fig, 11 shows the handles with ergonomically friendly and shaped plastic sleeves hiding the slider arms. The plastic sleeves serve to contain the slider arms and also improve the handle grip for improved performance.

The present invention can be made by using several processes, or by the use of 3D computerised machinery. The present invention can be made from a variety of materials suitable to its particular use. The present invention can be incorporated into different types of hand tools.

Further modifications will be apparent to those skilled in the art, without departing from the scope of the present invention.

Claims

1. A locking mechanism for pliers or clamps incorporated into first class levers that use symmetrical jaws and handles on each side and the mechanism is connected via a threaded hole in the main fulcrum and connections in the handles.

2. A locking mechanism for pliers or clamps according to claim 1 in which channelled pivots in the handles hold and force the arms of a V shaped slider block up and down an unthreaded section of a thumbscrew with a fixed stopper which is attached to the main fulcrum with threaded hole.

3. A locking mechanism for pliers or clamps according to claim 1 and 2 in which a stopper fixed to the unthreaded end of the thumbscrew nearest the fulcrum locks against the V shaped slider block thumbscrew when turned anti-clockwise whilst the handles are squeezed, locking the slider arms, thus preventing the jaws from opening and also performing a clamping operation

4. A locking mechanism for pliers or clamps according to claim 1 and 2 in which the thumb screw is positioned conveniently and is accessible to fore finger and thumb of either hand particularly for a one handed clamping operation whilst the other hand is free to hold the work piece.

5. A locking mechanism for pliers or clamps according to claim 1 and 2 in which the handles are shaped to allow the threaded end of the thumbscrew easy access.

6. A locking mechanism for pliers or clamps according to claim 1 and 2 whereby the mechanism is incorporated centrally into the configured jaws and handles.

7. A locking mechanism for pliers or clamps according to claim 1 and 2 whereby the handles may have ergonomically friendly shaped plastic sleeves and also sleeves that can hide the slider arms.

8. A locking mechanism for pliers or clamps according to claim 1 and 2 in which the present invention can be incorporated into different types of hand tools using a first class lever arrangement.

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Application No: GB1714597.0 Examiner: Mr Ian Blackmore