Formwork Pin Assembly Automatic Locking Mechanism
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Solution Overview
Problem
Existing formwork pin assemblies for connecting forming panels in cementitious material casting are inefficient due to frequent loss of loose pieces, increased labor costs, and multiple steps required for assembly and disassembly, with issues like pin bounce-back and mushrooming of engagement pins.
Innovation Solution
A pin assembly with a biasing member and latch that automatically secures and disassembles forming panels, using a hardened core pin insert and biased catch to prevent bounce-back and mushrooming, allowing for single-tool disassembly and secure panel engagement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a retractable pin and latch mechanism is used to connect forming panels, then the panels can be secured together, but multiple manual steps are required including hammer strikes, manual latch engagement, and pin retraction, increasing labor time and complexity
Solution Approach 1:
The pin assembly automatically performs multiple functions: the spring-loaded pin self-extends through the hole when the latch is raised, self-secures through the panel, and the latch automatically engages with the panel edge to lock the pin in place. During disassembly, raising the latch automatically retracts the pin and stows the latch without requiring manual intervention for each step.
Solution Approach 2:
The invention combines the pin extension, pin securing, and latch engagement functions into a single automated sequence triggered by raising the latch. Similarly, disassembly merges pin retraction and latch stowing into one action, eliminating the need for separate hammer strikes and manual operations.
2Reliability
If the pin is made longer to prevent bouncing back and falling out, then connection reliability improves, but the latch cannot travel far enough to properly secure the panels
Solution Approach 1:
The pin is segmented into two distinct components: a reusable housing-mounted pin assembly and a consumable hardened core pin insert. The pin insert provides the necessary length and structural integrity to prevent bouncing and falling out, while the housing-mounted assembly provides the mechanical advantage for latch engagement and retraction.
Solution Approach 2:
The hardened core pin insert acts as an intermediary element between the pin assembly and the panels. It provides the structural function of a long, rigid pin that prevents bouncing and falling out, while allowing the latch to engage with the housing-mounted pin assembly rather than the full length of the pin.
3Reliability
If elongated pins with increased tapering are used to secure panels, then initial securing effectiveness improves, but mushrooming of the pin tip occurs and cost increases
Solution Approach 1:
The pin system uses a composite structure combining the housing-mounted pin assembly (providing mechanical function) with a hardened core pin insert (providing structural integrity and resistance to deformation). The hardened steel insert prevents mushrooming while maintaining the necessary tapering for effective panel engagement.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution significantly reduces labor time and costs by enabling automatic locking and stowing of panels with fewer steps, preventing pin loss and mushrooming, and allowing faster disassembly of formwork frameworks.
Implementation Method 1
a biasing member operable to bias the engagement pin in a forward direction relative to the housing. When it is desired to lock the first and second forming panels, the latch is raised compressing, creating an extension force, and tensioning, creating a rotational force, in the biasing member
Implementation Method 2
a hardened core pin insert coupled to the hollow-tipped engagement pin to prevent mushrooming of the tip of the engagement pin
Data Source
AI summary
A pin assembly (20) having a substantially automatic locking and stowing mechanism, including a latch (90), a biasing member (70), and an engagement pin (30). The engagement pin includes a hollow-tipped forward end, allowing a hardened core pin insert to be introduced. The latch is operably connected to the pin assembly such that raising the latch compresses, creating an extension force, and tensions, creating a rotational force, the biasing member, and applying a force to the rearward end of the pin assembly causes the extension force to drive the engagement pin forward through aligned openings of the adjacent panels and the rotational force drops the latch securing the two panels in place. The adjacent panels are easily disconnected by raising the latch, compressing, creating an extension force, and tensioning, creating a rotational force, the biasing member, and applying a force to the forward end of the pin assembly causing the extension force to drive the engagement pin back through the aligned openings of the framework panels and the rotational force to drop and stow the latch for later use. A biased catch (75) secures the engagement pin in a retracted position.