1. A safety brake system for a trailer comprising:
a brake end comprising a brake unit adapted to be secured to a trailer and positioned to block movement of the trailer when actuated;
an actuation end adapted to be secured to a front end of the trailer comprising:
a hitch ball coupler comprising a hand portion defining a concavity adapted to receive a hitch ball of a vehicle,
a mechanism operatively connected to the hitch coupler and displaceable with respect thereto, the mechanism comprising a probe plunger displaceable between an unhitched position in which the probe plunger penetrates inside the concavity free of the hitch ball, and a hitched position in which the probe plunger is displaced at least partially out of the concavity by contact with the hitch ball, the mechanism being directly connected to the brake unit, the mechanism transmitting movement of the probe plunger to the brake unit so as to actuate said brake unit when the probe plunger moves to the unhitched state, the mechanism transmitting movement of the probe plunger to the brake unit so as to release said brake unit when the hitch bail is received in the hitch ball coupler to move the probe plunger to the hitched state and
a biasing unit to continuously bias the probe plunger toward the unhitched state, whereby the probe plunger automatically penetrates the concavity when the hitch coupler of the trailer is separated from the hitch ball of the vehicle to actuate the brake unit.
2. The safety brake system according to claim 1, wherein an opening is defined in a top portion of the hand portion for penetration of the probe plunger into the concavity.
3. The safety brake system according to claim 1, wherein the mechanism comprises an elongated member pivotally mounted at to the hitch ball coupler, with the probe plunger being secured to the elongated member.
4. The safety brake system according to claim 3, wherein the elongated member is a U-shaped bracket pivotally mounted at opposed ends to the hitch ball coupler.
5. The safety brake system according to claim 3, wherein the mechanism further comprises a lever operatively connected to the elongated member for concurrent movement, the lever being manually displaceable to release brakes of the brake unit.
6. The safety brake system according to claim 3, wherein the mechanism further comprises a joining unit for joining a cable of the brake unit to at least one of the elongated member and of the lever, a portion of the joining unit being mounted to the hitch ball coupler to translate relative to the trailer, the joining unit being connected to the cable of the brake unit such that a translation of the portion of the joining unit actuatesreleases the brakes of the brake unit.
7. The safety brake system according to claim 6, wherein the joining unit comprises a rack block meshed with a pinion portion of one of the elongated member and of the lever.
8. The safety brake system according to claim 7, wherein the joining unit further comprises a cable block releasably engaged to the rack block, the cable block being mounted to the hitch ball coupler to translate relative to the trailer, the cable block being connected to the cable of the brake unit such that a translation of the cable block actuatesreleases the brakes of the brake unit.
9. The safety brake system according to claim 8, further comprising a safety block and biasing component, the safety block being operatively mounted to the hitch ball coupler to bias the cable block into engagement with the rack block.
10. The safety brake system according to claim 9, further comprising a safety cable connected at a first end to the safety block and adapted to be connected at a second end to the vehicle, such that a pulling force on the safety cable displaces the safety block out of biasing the cable block from the rack block to actuate the brakes.
11. The safety brake system according to claim 9, wherein the safety block is mounted to the hitch ball coupler to translate relative to the trailer in a direction angled relative to a direction of the cable block.
12. A trailer assembly comprising:
a trailer body supported by wheels, and a trailer tongue; and
the safety brake system as defined in any one of claims 1 to 11, the hitch ball coupler being mounted to the trailer tongue.
13. The trailer assembly according to claim 12, wherein the brake is shaped to block at least one of the wheels of the trailer.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A repair circuit for substituting a defective cell with a redundancy cell, comprising:
an antifuse programmed by a voltage difference of both ends thereof;
a power-up reset circuit for generating a first and a second power stabilization signal;
a programming circuit for programming the antifuse;
a detection circuit for detecting whether the antifuse is programmed or unprogrammed by using the first and the second power stabilization signals, wherein the detection is performed during or after a power stabilization period; and
a latch circuit for latching the result of the detection, wherein the defective cell is substituted with the redundancy cell in response to an output of the latch circuit.
2. The repair circuit as recited in claim 1, further comprising:
a pulse generating means, connected between the power-up reset circuit and the detection circuit, for generating a first and a second short pulse in order to detect whether the antifuse is programmed or unprogrammed after the power stabilization.
3. The repair circuit as recited in claim 2, wherein the pulse generating means produces the first and the second short pulses by using the first control signal and one of a chip select signal and a row address strobe signal.
4. The repair circuit as recited in claim 3, wherein the pulse generating means includes:
a phase inversion level shifter receiving either the chip select signal or the row address strobe signal as its input;
a NAND gate for combining an output of the phase inversion level shifter and the first control signal;
a delay circuit for delaying and inverting an output of the NAND gate;
a NOR gate for combining the outputs of the NAND gate and the delay circuit to generate the first short pulse; and
an inverting gate for inverting an output of the NOR gate to generate the second short pulse.
5. The repair circuit as recited in claim 1, wherein the programming circuit includes:
a first PMOS transistor, connected between a power voltage node and one end of the antifuse, whose gate is provided with a high voltage when the antifuse is programmed and is also connected to said one end of the antifuse;
the antifuse connected between the first PMOS transistor and a first node;
a first NMOS transistor, connected between the first node and a second node, whose gate is connected to the power voltage node;
a second NMOS transistor, connected between the second node and ground, which gate is provided with an address for the programming; and
a third NMOS transistor, connected between the power voltage node and the second node, whose gate is provided with a precharge signal.
6. The repair circuit as recited in claim 1, wherein one junction of each of the second and the third NMOS transistors has an N-type.
7. The repair circuit of claim 5, wherein the detection circuit includes:
a second PMOS transistor, connected between the power voltage node and a third node, whose gate is connected to the gate of the first PMOS transistor;
a third PMOS transistor, connected between the third node and a fourth node, whose gate is provided with the first control signal;
a fourth NMOS transistor, connected between the fourth node and ground, whose gate is provided with the second control signal; and
a fifth NMOS transistor, connected with the second NMOS transistor in parallel, whose gate is provided with the second control signal.
8. The repair circuit as recited in claim 7, wherein one junction of the fifth NMOS transistor has an N-type.
9. The repair circuit as recited in claim 7, wherein the detection circuit further includes:
a fourth PMOS transistor, connected with the second PMOS transistor in parallel in order to prevent a gate-to-junction breakdown of the second PMOS transistor, whose gate is provided with the second control signal.
10. The repair circuit as recited in claim 1, wherein the programming circuit includes:
a first PMOS transistor, connected between the power voltage node and one end of the antifuse, whose gate is provided with a high voltage when the antifuse is programmed and is also connected to said one end of the antifuse;
the antifuse connected between the first PMOS transistor and a first node;
a first NMOS transistor, connected between the first node and a second node, whose gate is provided with the power voltage node; and
a third NMOS transistor, connected between the power voltage node and the second node, whose gate is provided with a precharge signal.