diff --git a/src/BulletCollision/CollisionShapes/btTriangleBuffer.cpp b/src/BulletCollision/CollisionShapes/btTriangleBuffer.cpp
new file mode 100644
index 000000000..b926398dc
--- /dev/null
+++ b/src/BulletCollision/CollisionShapes/btTriangleBuffer.cpp
@@ -0,0 +1,41 @@
+/*
+Bullet Continuous Collision Detection and Physics Library
+Copyright (c) 2003-2006 Erwin Coumans  http://continuousphysics.com/Bullet/
+
+This software is provided 'as-is', without any express or implied warranty.
+In no event will the authors be held liable for any damages arising from the use of this software.
+Permission is granted to anyone to use this software for any purpose, 
+including commercial applications, and to alter it and redistribute it freely, 
+subject to the following restrictions:
+
+1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
+2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
+3. This notice may not be removed or altered from any source distribution.
+*/
+
+#include "btTriangleBuffer.h"
+
+
+///example usage of this class:
+//			btTriangleBuffer	triBuf;
+//			concaveShape->processAllTriangles(&triBuf,aabbMin, aabbMax);
+//			for (int i=0;i<triBuf.getNumTriangles();i++)
+//			{
+//				const btTriangle& tri = triBuf.getTriangle(i);
+//				//do something useful here with the triangle
+//			}
+
+
+
+
+void btTriangleBuffer::processTriangle(btVector3* triangle,int partId,int  triangleIndex)
+{
+		btTriangle	tri;
+		tri.m_vertex0 = triangle[0];
+		tri.m_vertex1 = triangle[1];
+		tri.m_vertex2 = triangle[2];
+		tri.m_partId = partId;
+		tri.m_triangleIndex = triangleIndex;
+			
+		m_triangleBuffer.push_back(tri);
+}
diff --git a/src/BulletCollision/CollisionShapes/btTriangleBuffer.h b/src/BulletCollision/CollisionShapes/btTriangleBuffer.h
new file mode 100644
index 000000000..6b3c33209
--- /dev/null
+++ b/src/BulletCollision/CollisionShapes/btTriangleBuffer.h
@@ -0,0 +1,60 @@
+/*
+Bullet Continuous Collision Detection and Physics Library
+Copyright (c) 2003-2006 Erwin Coumans  http://continuousphysics.com/Bullet/
+
+This software is provided 'as-is', without any express or implied warranty.
+In no event will the authors be held liable for any damages arising from the use of this software.
+Permission is granted to anyone to use this software for any purpose, 
+including commercial applications, and to alter it and redistribute it freely, 
+subject to the following restrictions:
+
+1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
+2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
+3. This notice may not be removed or altered from any source distribution.
+*/
+
+#ifndef BT_TRIANGLE_BUFFER_H
+#define BT_TRIANGLE_BUFFER_H
+
+#include "btTriangleCallback.h"
+#include <vector>
+
+struct	btTriangle
+{
+	btVector3	m_vertex0;
+	btVector3	m_vertex1;
+	btVector3	m_vertex2;
+	int	m_partId;
+	int	m_triangleIndex;
+};
+
+///btTriangleBuffer can be useful to collect and store overlapping triangles between AABB and concave objects that support 'processAllTriangles'
+class btTriangleBuffer : public btTriangleCallback
+{
+
+	std::vector<btTriangle>	m_triangleBuffer;
+	
+public:
+
+
+	virtual void processTriangle(btVector3* triangle, int partId, int triangleIndex);
+	
+	int	getNumTriangles() const
+	{
+		return int(m_triangleBuffer.size());
+	}
+	
+	const btTriangle&	getTriangle(int index) const
+	{
+		return m_triangleBuffer[index];
+	}
+
+	void	clearBuffer()
+	{
+		m_triangleBuffer.clear();
+	}
+	
+};
+
+
+#endif //BT_TRIANGLE_BUFFER_H
\ No newline at end of file
diff --git a/src/BulletDynamics/ConstraintSolver/btGeneric6DofConstraint.cpp b/src/BulletDynamics/ConstraintSolver/btGeneric6DofConstraint.cpp
index fc47390d7..b5783f824 100644
--- a/src/BulletDynamics/ConstraintSolver/btGeneric6DofConstraint.cpp
+++ b/src/BulletDynamics/ConstraintSolver/btGeneric6DofConstraint.cpp
@@ -309,12 +309,16 @@ void	btGeneric6DofConstraint::solveConstraint(btScalar	timeStep)
 			}
 		
 			//impulse
-			btScalar impulse = -(tau*rel_pos/timeStep + damping*rel_vel) * jacDiagABInv;
-			m_accumulatedImpulse[i + 3] += impulse;
+			
+			btScalar normalImpulse= -(tau*rel_pos/timeStep + damping*rel_vel) * jacDiagABInv;
+			float oldNormalImpulse = m_accumulatedImpulse[i+3];
+			float sum = oldNormalImpulse + normalImpulse;
+			m_accumulatedImpulse[i+3] = sum > hi ? 0.f : sum < lo ? 0.f : sum;
+			normalImpulse = m_accumulatedImpulse[i+3] - oldNormalImpulse;
 			
 			// Dirk: Not needed - we could actually project onto Jacobian entry here (same as above)
 			btVector3 axis = kSign[i] * axisA.cross(axisB);
-			btVector3 impulse_vector = axis * impulse;
+			btVector3 impulse_vector = axis * normalImpulse;
 
 			m_rbA.applyTorqueImpulse( impulse_vector);
 			m_rbB.applyTorqueImpulse(-impulse_vector);