Here is another great idea submitted to us that we would like to see on the market.  Please leave comments. We are starting a new monthly tool giveaway, to enter leave a relevant comment or post in our forum.


This tool was developed after realizing that the typical clamp used in the construction industry is of limited use as only a small percentage of framing members are parallel and adjacent to one another. A far greater percentage of these members are perpendicular to one another, a situation where a typical clamp is essentially useless. While a 90 degree clamp would be ideal for this situation, none of the clamps available are well suited for framing. They are all cumbersome to use, being based on the time consuming turn screw mechanism, and often block convenient access to either toe or end nailing. The tool disclosed here is designed to overcome these deficiencies and fill this need for a 90 degree framing clamp optimized for the construction industry that is simple to use, quick in operation and cost effective to manufacture.


A 90 degree framing clamp specifically designed to be used in the construction industry should meet the following requirements:

  1. It should be optimized to be used with 2×4 lumber such that it provides clamping forces down the centerline of each member and no additional adjustments are needed to accept these framing members.
  2. It should allow for single handed operation, leaving the other hand free to align the framing members.
  3. A single clamping action should be required, as opposed to one action to clamp the framing member and another to draw them together.
  4. It should allow for easy access to both toe nailing and end nailing.
  5. It should be easy to use and quick in operation.

While the above parameters must be met and constrain the design, the following is a list of factors that ease some of the design requirements:

  1. Since we are dealing with framing lumber, marring the surface is not a concern. This will allow the clamping surfaces to have aggressive profiles with high frictional values.
  2. The clamp is not required to hold the framing members perfectly 90 degrees to one another as it is typical to use layout lines to provide the correct orientation. The clamp only needs to hold the framing members approximately perpendicular to one another such that the vertical member may be easily placed on the required layout line.

Figure 1


Fig.1 is a perspective view of the tool. While the internal mechanism is based on the typical quick grip or pistol grip clamps, it overcomes several deficiencies in these designs. First, it is immediately apparent to the user that they will be able to apply more leverage and consequently greater clamping force with this design. This is a major drawback of the quick grip clamps and one the user is inherently aware of as the clamping force is limited to the users grip strength. Second, the typical quick grip clamps require the user to orient their hands in a particular position in order to operate the clamp. This design provides more freedom in this respect, as it may be operated from many different angles. Finally, from a marketing standpoint this mechanism instills the feeling that you have developed a new clamp from the ground up as opposed to simply modifying a standard pistol grip clamp.

Note: The components are colored so they may be easily identified, not to denote the type of material used.


Figure 2


Fig.2 illustrates the major components of the clamp where the main housing has been hidden from view. The cam located at the pivot end of the lever handle provides the clamping force via its interaction with the blue actuator plate. The steel hoop attached to this cam and looped around the green brake plate provides the brake release function. Finally, the mechanism for clamping the framing member which passes through the main housing is provided by the grey cam clamps. These clamps would preferably be spring loaded such that they would automatically close in on any framing member placed between them. The steel hoop located at the rear serves as both an axle for these gray cam clamps and a structural member to counteract the spreading forces they induce. This combination would provide a system that would immediately begin grabbing any framing member placed between them.

Figure 3


Fig.3 is a side view illustrating the internal mechanism of the tool. As stated previously the mechanism driving this clamp is based on the typical pistol grip clamp, which are well known in the field. Therefore, I will not waste time describing the shared features and only touch on the elements that differ.

The primary difference is the use of a lever handle as opposed to a trigger to leverage the blue actuator plate. In the figure above the lever handle has rotated the cam into a position that produces the maximum displacement between the blue actuator plate and the cam’s pivot point. It should be noted that in this position the contact point between the cam and the blue actuator plate has moved past the cams apex. This relationship creates a force which tends to rotate the lever handle in the clockwise direction, restraining it in the horizontal position. This is an advantage over the typical pistol grip clamps. With these clamps there is a point where the users grip strength is inadequate to move the bar through the brake and any extra clamping force applied is lost once the user releases the trigger. This is not the situation with the mechanism discussed here as the extra clamping force is held when the lever arm is in the position of maximum displacement .


Figure 4


Fig.4 is a side view of the tool where the lever handle is in the minimum throw position. The lever handles range of motion required to operate the clamp reside anywhere from Fig.3 to Fig.4. When the lever is in the above position the steel hoop attached to the cam is just touching the green brake plate and the left side of the lever is resting on the red pseudo brake release button. If the handle is rotated clockwise then the clamping force is increased, however if rotated counter clockwise the pseudo brake release button is depressed as the steel hoop simultaneously disengages the green brake.

Figure 5


Fig.5 is a side view of the tool where the lever handle is in the brake release position. In this position the red pseudo brake release button has been fully depressed and the steel hoop has pulled the green brake in a more vertical position, releasing the clamping force. The blue actuator plate is also canted towards vertical as well and whole assembly may move freely up and down the steel I beam. It would be convenient to provide a simple detent mechanism (not shown) to hold the lever handle in this position or the one shown in Fig.4.

The red pseudo brake release button serves several purposes. First, it serves as a visual indicator to alert the user when the minimum throw position has been reached. Second, as the brake release mechanism is hidden from the user, releasing it may not be immediately apparent to them. However, if the button was brightly colored and clearly marked as the brake release then operation of the tool would be intuitive.




Figure 6


Fig.6 illustrates the clamp in use. The fixed end of the clamp residing on the horizontal framing member has an open center section to allow end nailing as seen on the right. Also the main housing attached to the vertical member is placed far enough back to provide easy access to toe nailing. In addition, due to the design the clamping process is a single handed operation as movement is restricted along both the vertical and horizontal axis. This would allow the use of both hands to align the framing members after the clamp is in place. Once the framing members are set, all that is required are a few quick pumps of the lever handle to finalize the clamp.






Figure 7


Fig.7 illustrates an optional compressible actuator assembly with the exploded view on the left and the assembled part in use on the right. The purpose of this optional part is to prevent the user from overstressing the tool by limiting the maximum possible clamping force. The blue part serves the same purpose as the blue actuator plate discussed in the previous figures with the addition of an integrated post. A yellow elastomeric spring slides over this post and is capped with a steel washer as seen in the complete assembly on the right. The cam now interacts with and applies forces to the steel washer and depending on the elastomeric spring choice a wide variety of compliances may be provided. For example, if the desired maximum clamping force was 600 lbs and the maximum cam displacement was 0.25” then an elastomeric spring would be chosen that compressed 0.25” at a clamping force of 600 lbs. Therefore, at this maximum clamping force the cam would simply compress the elastomeric spring as opposed to creating any additional clamping force. Taking into account the compliance of the system external to the assembly and the fact that the displacement path is not in line with the compression path, the FIBROFLEX 90 Shore A yellow elastomeric spring would be a close match and is the part modeled in the figure above.


Figure 8


Fig.8 illustrates an alternative method of clamping the framing member that passes through the main housing.

Figure 9


Fig.9 illustrates an alternative version of the clamp.  In this version standard pistol grip technology is used and therefore the internal mechanism has not been shown as any of the existing designs may be used. This is by far the safer design, pistol grip mechanisms have stood the test of time and the product would retain a high degree of user familiarity. However, every person that has seen both versions chose the original version presented here by a large margin. User familiarity is a double edge sword in this case as the user is also very aware of this technologies shortcoming. They were all tired of having to exert maximum strength, often squeezing the trigger as hard as they can with both hands, in order to achieve maximum clamping force. We have all seen the typical scenario where someone has used a pistol grip clamp solely to squeeze the trigger of another pistol grip clamp. For these reasons everyone chose the original design, as they realized a long throw lever in combination with small displacement cam could achieve a high clamping force with minimal effort.












The number of clamps available today could fill a tool coral. They come in every shape and size, with a wide range of operating mechanisms. Many trades, from welding to picture framing, have clamps specifically designed to serve their industry. However, not one company produces a clamp dedicated solely to the construction industry. This is that clamp. It was optimized and designed with one purpose in mind, to assist the user in fastening two framing members that reside perpendicular to one another, a situation that occurs time and time again in the construction industry. It is an extra set of hands that everyone would use, from the layman to the professional contractor.

This clamp targets a market that is wide open and free of competition. It would stand alone in the tool coral as the only one designed for our industry next to a sea of generic clamps that serve no specific industry at all. It would be fitting if C.H. Hanson, a company whose name is synonymous with construction industry, be the first company to build a clamp dedicated solely to that industry.


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