FR2743627A1 - System for locking suspension cord of plumb-bob at chosen length - Google Patents

Abstract

The plumb-bob has a weight (9) fixed to the end of a suspension cord (8), the other end of the cord passes through a guide plate (2), and a cord locking housing (1) which is fixed to the guide plate. The locking housing includes a pushbutton (3) whose axis is perpendicular to and is in the same plane as the cord passing through the housing. The pushbutton acts against a spring (5). The pushbutton has a semi-circular cut-out in it which passes around the cord when the button is pushed in.. The button can be locked in the cord gripping position by means of a screw(7).

Description

SELF-LOCKING LEAD WIRE
The present invention relates to an if device used to block the plumb line cord to immobilize the weight at the desired height.

Traditionally the plumb line consists of a mass
(9) and a simple square plate (2) pierced for the free passage of the cord (8). It is therefore necessary, at the time of use, to maintain the plate in the desired position, and at the same time immobilize the wire stretched by the weight, at the correct length.

These two maneuvers to be performed simultaneously are often difficult, especially since this instrument is used on construction sites, therefore in positions which are sometimes difficult for the user.

The proposed devices only modify the upper part of this instrument, that is to say the guide plate (2); it does not change anything at the bottom, that is to say the mass suspended from the head of the cord.

With the device presented, the user can easily adjust the height position of the weight, either by acting (action F) on push button (3) to lower it, or e, 'pulling on one end of the wire to increase or decrease the useful length of the wire.

To simplify the representation and understanding, the cord (8) has not been shown in FIGS. 2 and 3.

Figure 1 is an overall perspective view.

The other views represent the proposed device. Figure 2 is a vertical section along the line AA passing through the axis of the pusher (3).

Figure 3 is a vertical section along the line BB passing through the axis of the part (4).

Figure 4 is a partial section according to Figure AA, showing a possible modification of the device.

Figure 5 is a schematic partial section showing the blocking of the wire (R).

The device is composed of a paralelepedic box (1) centered and fixed on a square plate (2). The whole is drilled right through in the center, for the free passage of the wire. The housing (1) comprises a pusher (3) whose axis is perpendicular and located in the same vertical plane as the hole for passage of the wire. This pusher driven by the spring (5), comprises two axial mortises, one opening into the aforementioned hole, the other, perpendicular to the previous one, receives the axis (4) which ensures the guiding and the stop in limit switch of this pusher. When the cord is in place, it is trapped at the bottom of the mortise by the part (4), see figure 5.

This self-locking of the cord is reliable, without any risk of the wire jamming whatever its diameter (however) compatible with the dimensions of the device) because this wire theoretically undergoes no deviation, the contacts at A and B with the parts (3) and (4) are punctual and diametrically
Opposed. see figure 5.

Only the internal parts ensure this self-locking, the box simply contributes to the guiding and orientationt of entry and exit of the wire.

Figure 4 shows a supplement to the device studied, to more or less harden the sliding of the cord by acting on the initial pressure of the spring 5 with one screw (6) and its locknut.

With the proposed device, all the internal parts are cylindrical, therefore easy to produce. Disassembly, for cleaning for example, is simple. just drive out the axis (4), note that it could have a threaded end.

Please also note that the housing (1) and the plate (2) assembled by the screws (7) can be in one piece, and that this shoemaker (.1) can be associated with an external device, stirrup, permanent magnet, allowing its immobilization on the element whose verticality is to be controlled.

Claims (5)

- 1 - Plumb line comprising a mass (9) fixed to the end of a cord (8) and suspended from a guide plate (2) in which this slider slides, characterized by the self-locking of the cord by a device (1) fixed on this plate. The sliding of the wire is carried out either by pulling on one of the ends of the wire, or by pressing sut. the pusher (3) (action F), when the weight is suspended, it descends by itself. - 2 - Plumb bob according to claim 1, characterizes that the device consists of a housing (1) fixed on a plate (2); all pierced right through, in the center for the free passage of the cord (8). the housing includes a pusher (3) whose axis is perpendicular and in the same plane as the axis of passage of the cord. the pusher driven by the spring (5) comprises two axial mortises; one opening into the hole for passage of the cord, the other perpendicular to the previous one, receives one axis (4) which ensures the guidance of the pusher and its stop and the race fir; cord is thus wedged between parts (3) and (4), see figure 5. - 3 - Plumb line according to claim 2, characterized in that only the internal parts (3) and (4) ensure the blocking of the wire (8). The box (1) intervening only for the guidance and the orientation of entry and exit of the wire. This wire undergoes, theoretically no deviation, the contacts at A and B on it are punctual and diametrically opposite, which avoids any untimely jamming of this wire. For disassembly (cleaning of the mechanism), simply remove the axle (4). One end could be threaded. - 4 - Plumb bob, according to the preceding claims, characterized in that the self-locking force due to the action of the spring (5) could be adjusted by adding the screw (6) and its lock nut: the initial pressure of the spring being modified, Figure 4. On the other hand, the housing (1) and the plate (2) assembled by the screws (7) can be in one piece. - 5 - Plumb bob according to one of the preceding claims, characterized in that this box can be associated with an external device, stirrup. permanent magnet, allowing its immobilization on the element whose verticality is to be controlled.